[libc++][format] Buffer changes proof-of-concept

[Mordante]

Summary

In D110495 @vitaut suggested a different approach for the buffers. This is
a proof-of-concept of that idea.

• There's a new __output_buffer that contains the fixed size buffer. The __iterator_wrapper_buffer now always call the put of this buffer. When the buffer is full the buffer calls flush of one of the original buffers.
• The original buffers are still called buffer, but they're no longer buffers; they are more a write policy. This needs to be renamed once backported.
• All format functions call __output_buffer:;flush(). It would be possible to do that with an RAII buffer, but since flush then throw from the destructor some guards were needed. This slowed the performance.
• There are before and after benchmark timings using D110501 Before -> D110500 After -> This patch. In general this approach seems to be an improvement. The notable exception is when using std::list::begin() as iterator. This hasn't been investigated, since I don't expect this to be used in real applications.
• This patch is just for discussion, the code is not ready for review and should be folded back in the earlier patches in this series. Especially the two objects called buffer should be changed.

Depends on D110500

[• Quuxplusone]

libcxx/include/__format/buffer.h

104–110

@vitaut wrote on D110495:

I think D112361 is a step in the right direction. You can do even better and make it represent a contiguous (not necessarily fixed-size) buffer with a single type-erased reallocation/flush function. Then it can be used to write to contiguous containers like vector and string which is a common case directly avoiding copies. This is basically what {fmt} does.

Charlie Barto also showed MSVC STL doing that approach, in his CppCon talk on Thursday. https://cppcon.digital-medium.co.uk/thursday-recordings/
IIRC, basically they have _Size, _Capacity, virtual void _Grow(); and whenever _Size == _Capacity they call _Grow. I guess I remain fuzzy on the details of what _Grow would actually do for a std::string (does it resize? does it merely reserve?).

[Mordante]

libcxx/include/__format/buffer.h

104–110

That looks a lot like what fmt does. I tested with a similar approach, but the virtual call seems to have a measurable impact over the __fun_(__buffer_.begin(), __buffer_it_, __obj_); method.

[Mordante]

Update the design based on the latest feedback.
Still a proof-of-concept to discuss the way ahead.

Note the CI will probably fail since it's based on older CI files.

[vitaut]

libcxx/include/__format/buffer.h

63

You might also want to provide an API for appending multiple chars at a time (e.g. a string_view) which can be implemented more efficiently than appending individual characters.

68–69

Wouldn't this overwrite the data for direct storage?

102

Did you mean internal_storage? (missing "n")

[Mordante]

libcxx/include/__format/buffer.h

63

I already considered that, but I prefer to do that in a separate commit.
I'll add a TODO FMT in the source to make that intention clear.

68–69

No the flush of the direct storage only adjusts the output iterator. The output iterator needs to be updated when the the direct storage uses a __wrap_iter<_CharT*> instead of a _CharT*.

102

Thanks for catching this typo.

[vitaut]

libcxx/include/__format/buffer.h

60–61

Looks like this doesn't need to be a template because it is only called with internal storage.

63

Makes sense.

87–92

Not sure if it matters but __ptr_, __size_ and __capacity_ are accessed way more frequently than __flush_ and __obj_ so maybe put them first?

117–123

__ptr_ and __capacity_ duplicate members of __format_buffer. Is it possible to get rid of them?

203–204

There is a naming inconsistency here (buffer vs writer): the class is called __buffer_selector while it selects between __writer_*.

[Mordante]

libcxx/include/__format/buffer.h

60–61

Good point, I changed the call to just give the new values for __ptr_ and __capacity_ as argument.

117–123

An interesting observation. I've tested it and these members are indeed not required. This means the entire class can just be an empty class. Since __format_buffer still needs to select between this storage and the __interal_storage it can't be removed.

[Mordante]

Addresses review comments.
@vitaut's suggestion turned __direct_storage into an empty class, this avoids some duplication but required a small rewrite.
The CI will fail.

This version will be used to update the earlier patches in this series so this patch can be applied in smaller steps.

[vitaut]

libcxx/include/__format/buffer.h

104–110

The virtual call can be replaced with an indirect call (similar to __flush_ in this diff) and it should only be called rarely (normally when you need to do a reallocation). But to see the benefits you really need to make use of writing to the buffer directly. It doesn't make much sense to test with a push_back API which only writes individual characters. I guess the latter is the reason why you even see virtual calls at all. The current approach while an improvement has an extra level of buffering and likely be slower in common scenarios compared to direct output. I think you can even implement the flush method using the grow method + a fixed intermediate buffer so the latter is strictly more powerful and can address cases where an extra buffering helps reducing reallocations.

[Mordante]

Please note that the changes in this patch have been applied to the other patches in the stack. So this patch can probably be abandoned.
(For now I keep it open, but remove it from the review queue.)

libcxx/include/__format/buffer.h

104–110

It seems this comment has moved and not really attached to where the comment belongs. I've there changes:

• A direct buffer (char*, std::vector<char>::begin(), std::string::begin()) writes directly to the underlying character pointer. The flush there is used to keep track of the number of writes. A std::string::iterator is a std::wrap_iter. To return the proper iterator this calculation is done at the end. The direct buffer should only flush once since its capacity is size_t(-1). (For format_to_n the capacity of the buffer is limited to n.)
• An indirect buffer (all other iterators) write to an internal buffer and are copied to the output during the flush. When it's a std::back_insert_iterator for an container with an insert member it uses insert else it just copies it.

Making the internal buffer a variable size might help. However during testing using a larger internal buffer didn't have a real affect on the benchmarks. This might change when I add insert operations for std::string_view in the buffer. I like to investigate this once I start working on that part.

[vitaut]

libcxx/include/__format/buffer.h

104–110

The comment is not attached to something in particular, I was just continuing the discussion started by Arthur. Handling std::vector<char>::begin() directly is fine but it's not the case I was referring to and it's less interesting because of being generally unsafe. The common case is std::back_insert_iterator to a contiguous container and that's where it would be great to avoid an extra buffering. Handling of this case is the main difference between the flush approach from this diff and the grow approach used in {fmt}.

[vitaut]

libcxx/include/__format/buffer.h

104–110

Anyway, since "this patch can probably be abandoned", let's move the discussion to other diffs.

[Mordante]

This patch was mainly intended to discuss the direction and the changes have been applied to other patches in the series.

libcxx/after-v2/format.txt

+--------------------------------------------------------------------------------------------
+Benchmark                                  Time             CPU   Iterations UserCounters...
+--------------------------------------------------------------------------------------------
+BM_format_string<char>/1                39.0 ns         39.0 ns     17958178 bytes_per_second=24.4675M/s
+BM_format_string<char>/2                20.5 ns         20.5 ns     34080986 bytes_per_second=92.8685M/s
+BM_format_string<char>/4                11.6 ns         11.6 ns     60520112 bytes_per_second=329.61M/s
+BM_format_string<char>/8                6.65 ns         6.65 ns    103418744 bytes_per_second=1.11993G/s
+BM_format_string<char>/16               4.23 ns         4.23 ns    158993760 bytes_per_second=3.52259G/s
+BM_format_string<char>/32               3.52 ns         3.52 ns    199014720 bytes_per_second=8.47356G/s
+BM_format_string<char>/64               2.65 ns         2.65 ns    264567872 bytes_per_second=22.5289G/s
+BM_format_string<char>/128              2.22 ns         2.22 ns    315761408 bytes_per_second=53.7657G/s
+BM_format_string<char>/256              2.10 ns         2.10 ns    333994240 bytes_per_second=113.585G/s
+BM_format_string<char>/512              2.02 ns         2.02 ns    346097152 bytes_per_second=236.308G/s
+BM_format_string<char>/1024             1.98 ns         1.98 ns    352839680 bytes_per_second=480.966G/s
+BM_format_string<char>/2048             1.96 ns         1.96 ns    356339712 bytes_per_second=970.938G/s
+BM_format_string<char>/4096             1.93 ns         1.93 ns    362029056 bytes_per_second=1.92707T/s
+BM_format_string<char>/8192             1.91 ns         1.91 ns    366108672 bytes_per_second=3.89587T/s
+BM_format_string<char>/16384            1.90 ns         1.90 ns    367837184 bytes_per_second=7.82956T/s
+BM_format_string<char>/32768            1.90 ns         1.90 ns    368476160 bytes_per_second=15.6861T/s
+BM_format_string<char>/65536            1.95 ns         1.95 ns    359006208 bytes_per_second=30.5553T/s
+BM_format_string<char>/131072           2.21 ns         2.21 ns    316669952 bytes_per_second=53.9487T/s
+BM_format_string<char>/262144           2.32 ns         2.32 ns    301727744 bytes_per_second=102.743T/s
+BM_format_string<char>/524288           2.38 ns         2.38 ns    293601280 bytes_per_second=200.688T/s
+BM_format_string<char>/1048576          2.41 ns         2.41 ns    290455552 bytes_per_second=395.506T/s
+BM_format_string<wchar_t>/1             39.1 ns         39.1 ns     17886043 bytes_per_second=97.4408M/s
+BM_format_string<wchar_t>/2             20.1 ns         20.1 ns     34843370 bytes_per_second=379.926M/s
+BM_format_string<wchar_t>/4             10.6 ns         10.6 ns     66172232 bytes_per_second=1.40664G/s
+BM_format_string<wchar_t>/8             8.43 ns         8.43 ns     83001296 bytes_per_second=3.5361G/s
+BM_format_string<wchar_t>/16            4.78 ns         4.78 ns    146250240 bytes_per_second=12.4757G/s
+BM_format_string<wchar_t>/32            2.67 ns         2.67 ns    261437344 bytes_per_second=44.6226G/s
+BM_format_string<wchar_t>/64            1.95 ns         1.95 ns    360125120 bytes_per_second=122.547G/s
+BM_format_string<wchar_t>/128           1.69 ns         1.69 ns    415067904 bytes_per_second=282.868G/s
+BM_format_string<wchar_t>/256           1.57 ns         1.57 ns    444819712 bytes_per_second=605.712G/s
+BM_format_string<wchar_t>/512           1.47 ns         1.47 ns    475035136 bytes_per_second=1.26391T/s
+BM_format_string<wchar_t>/1024          1.33 ns         1.33 ns    527887360 bytes_per_second=2.81034T/s
+BM_format_string<wchar_t>/2048          1.23 ns         1.23 ns    567339008 bytes_per_second=6.03794T/s
+BM_format_string<wchar_t>/4096          1.21 ns         1.21 ns    578605056 bytes_per_second=12.3072T/s
+BM_format_string<wchar_t>/8192          1.20 ns         1.20 ns    582705152 bytes_per_second=24.8009T/s
+BM_format_string<wchar_t>/16384         1.22 ns         1.22 ns    574619648 bytes_per_second=48.9465T/s
+BM_format_string<wchar_t>/32768         1.29 ns         1.29 ns    542048256 bytes_per_second=92.3115T/s
+BM_format_string<wchar_t>/65536         1.30 ns         1.30 ns    539623424 bytes_per_second=184.056T/s
+BM_format_string<wchar_t>/131072        1.31 ns         1.31 ns    533463040 bytes_per_second=363.874T/s
+BM_format_string<wchar_t>/262144        3.25 ns         3.25 ns    215220224 bytes_per_second=293.379T/s
+BM_format_string<wchar_t>/524288        2.61 ns         2.61 ns    267911168 bytes_per_second=730.515T/s
+BM_format_string<wchar_t>/1048576       2.81 ns         2.81 ns    248512512 bytes_per_second=1.32355P/s

libcxx/after-v2/format_to.txt

+--------------------------------------------------------------------------------------------------------------------------
+Benchmark                                                                Time             CPU   Iterations UserCounters...
+--------------------------------------------------------------------------------------------------------------------------
+BM_format_to_string_back_inserter<std::string>/1                      38.2 ns         38.2 ns     18333555 bytes_per_second=24.9676M/s
+BM_format_to_string_back_inserter<std::string>/2                      40.0 ns         40.0 ns     17527305 bytes_per_second=47.6853M/s
+BM_format_to_string_back_inserter<std::string>/4                      45.7 ns         45.7 ns     15317233 bytes_per_second=83.496M/s
+BM_format_to_string_back_inserter<std::string>/8                      54.0 ns         54.0 ns     13024572 bytes_per_second=141.204M/s
+BM_format_to_string_back_inserter<std::string>/16                     65.4 ns         65.4 ns     10695650 bytes_per_second=233.225M/s
+BM_format_to_string_back_inserter<std::string>/32                      116 ns          116 ns      6006277 bytes_per_second=262.132M/s
+BM_format_to_string_back_inserter<std::string>/64                      175 ns          175 ns      3993632 bytes_per_second=348.208M/s
+BM_format_to_string_back_inserter<std::string>/128                     289 ns          289 ns      2417262 bytes_per_second=422.175M/s
+BM_format_to_string_back_inserter<std::string>/256                     543 ns          543 ns      1289593 bytes_per_second=449.871M/s
+BM_format_to_string_back_inserter<std::string>/512                    1034 ns         1034 ns       676159 bytes_per_second=472.252M/s
+BM_format_to_string_back_inserter<std::string>/1024                   2074 ns         2074 ns       337715 bytes_per_second=470.9M/s
+BM_format_to_string_back_inserter<std::string>/2048                   4081 ns         4081 ns       171526 bytes_per_second=478.61M/s
+BM_format_to_string_back_inserter<std::string>/4096                   8001 ns         8001 ns        87356 bytes_per_second=488.213M/s
+BM_format_to_string_back_inserter<std::string>/8192                  15781 ns        15781 ns        44413 bytes_per_second=495.062M/s
+BM_format_to_string_back_inserter<std::string>/16384                 31299 ns        31299 ns        22358 bytes_per_second=499.221M/s
+BM_format_to_string_back_inserter<std::string>/32768                 62251 ns        62251 ns        11240 bytes_per_second=501.998M/s
+BM_format_to_string_back_inserter<std::string>/65536                124433 ns       124434 ns         5625 bytes_per_second=502.276M/s
+BM_format_to_string_back_inserter<std::string>/131072               272979 ns       272975 ns         2560 bytes_per_second=457.917M/s
+BM_format_to_string_back_inserter<std::string>/262144               591913 ns       591913 ns         1183 bytes_per_second=422.359M/s
+BM_format_to_string_back_inserter<std::string>/524288              1228355 ns      1228360 ns          569 bytes_per_second=407.047M/s
+BM_format_to_string_back_inserter<std::string>/1048576             2515146 ns      2515125 ns          278 bytes_per_second=397.594M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1                51.9 ns         51.9 ns     13524073 bytes_per_second=18.3737M/s
+BM_format_to_string_back_inserter<std::vector<char>>/2                54.6 ns         54.6 ns     12813738 bytes_per_second=34.923M/s
+BM_format_to_string_back_inserter<std::vector<char>>/4                56.6 ns         56.6 ns     12329215 bytes_per_second=67.352M/s
+BM_format_to_string_back_inserter<std::vector<char>>/8                65.2 ns         65.2 ns     10739221 bytes_per_second=117.053M/s
+BM_format_to_string_back_inserter<std::vector<char>>/16               77.8 ns         77.8 ns      8994669 bytes_per_second=196.041M/s
+BM_format_to_string_back_inserter<std::vector<char>>/32                106 ns          106 ns      6576899 bytes_per_second=286.716M/s
+BM_format_to_string_back_inserter<std::vector<char>>/64                163 ns          163 ns      4271534 bytes_per_second=373.34M/s
+BM_format_to_string_back_inserter<std::vector<char>>/128               276 ns          276 ns      2529150 bytes_per_second=441.649M/s
+BM_format_to_string_back_inserter<std::vector<char>>/256               521 ns          521 ns      1344584 bytes_per_second=468.45M/s
+BM_format_to_string_back_inserter<std::vector<char>>/512              1020 ns         1020 ns       686051 bytes_per_second=478.741M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1024             1979 ns         1979 ns       353945 bytes_per_second=493.545M/s
+BM_format_to_string_back_inserter<std::vector<char>>/2048             3955 ns         3955 ns       177085 bytes_per_second=493.853M/s
+BM_format_to_string_back_inserter<std::vector<char>>/4096             7855 ns         7855 ns        88926 bytes_per_second=497.287M/s
+BM_format_to_string_back_inserter<std::vector<char>>/8192            15556 ns        15556 ns        45010 bytes_per_second=502.224M/s
+BM_format_to_string_back_inserter<std::vector<char>>/16384           30944 ns        30944 ns        22619 bytes_per_second=504.95M/s
+BM_format_to_string_back_inserter<std::vector<char>>/32768           62090 ns        62090 ns        11276 bytes_per_second=503.298M/s
+BM_format_to_string_back_inserter<std::vector<char>>/65536          123304 ns       123304 ns         5677 bytes_per_second=506.879M/s
+BM_format_to_string_back_inserter<std::vector<char>>/131072         247665 ns       247666 ns         2821 bytes_per_second=504.711M/s
+BM_format_to_string_back_inserter<std::vector<char>>/262144         498591 ns       498586 ns         1405 bytes_per_second=501.418M/s
+BM_format_to_string_back_inserter<std::vector<char>>/524288         994676 ns       994676 ns          704 bytes_per_second=502.676M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1048576       1991906 ns      1991878 ns          349 bytes_per_second=502.039M/s
+BM_format_to_string_back_inserter<std::list<char>>/1                  50.0 ns         50.0 ns     13977370 bytes_per_second=19.0642M/s
+BM_format_to_string_back_inserter<std::list<char>>/2                  63.5 ns         63.5 ns     11015869 bytes_per_second=30.0183M/s
+BM_format_to_string_back_inserter<std::list<char>>/4                  91.0 ns         91.0 ns      7690111 bytes_per_second=41.9195M/s
+BM_format_to_string_back_inserter<std::list<char>>/8                   159 ns          159 ns      4426156 bytes_per_second=48.0549M/s
+BM_format_to_string_back_inserter<std::list<char>>/16                  307 ns          307 ns      2296758 bytes_per_second=49.7331M/s
+BM_format_to_string_back_inserter<std::list<char>>/32                  603 ns          603 ns      1163850 bytes_per_second=50.5765M/s
+BM_format_to_string_back_inserter<std::list<char>>/64                 1174 ns         1174 ns       593496 bytes_per_second=51.9686M/s
+BM_format_to_string_back_inserter<std::list<char>>/128                2317 ns         2317 ns       301491 bytes_per_second=52.6818M/s
+BM_format_to_string_back_inserter<std::list<char>>/256                4627 ns         4627 ns       150960 bytes_per_second=52.7669M/s
+BM_format_to_string_back_inserter<std::list<char>>/512                9239 ns         9239 ns        75762 bytes_per_second=52.8525M/s
+BM_format_to_string_back_inserter<std::list<char>>/1024              18535 ns        18535 ns        37763 bytes_per_second=52.6868M/s
+BM_format_to_string_back_inserter<std::list<char>>/2048              37295 ns        37295 ns        18762 bytes_per_second=52.3695M/s
+BM_format_to_string_back_inserter<std::list<char>>/4096              74907 ns        74907 ns         9342 bytes_per_second=52.1477M/s
+BM_format_to_string_back_inserter<std::list<char>>/8192             150675 ns       150673 ns         4645 bytes_per_second=51.8508M/s
+BM_format_to_string_back_inserter<std::list<char>>/16384            301711 ns       301712 ns         2318 bytes_per_second=51.7879M/s
+BM_format_to_string_back_inserter<std::list<char>>/32768            604702 ns       604691 ns         1152 bytes_per_second=51.6793M/s
+BM_format_to_string_back_inserter<std::list<char>>/65536           1210372 ns      1210375 ns          576 bytes_per_second=51.6369M/s
+BM_format_to_string_back_inserter<std::list<char>>/131072          2437855 ns      2437817 ns          285 bytes_per_second=51.2754M/s
+BM_format_to_string_back_inserter<std::list<char>>/262144          5106059 ns      5105893 ns          127 bytes_per_second=48.963M/s
+BM_format_to_string_back_inserter<std::list<char>>/524288         10573176 ns     10572882 ns           62 bytes_per_second=47.2908M/s
+BM_format_to_string_back_inserter<std::list<char>>/1048576        21524883 ns     21524224 ns           31 bytes_per_second=46.4593M/s
+BM_format_to_string_begin<std::string>/1                              32.7 ns         32.7 ns     21368897 bytes_per_second=29.1297M/s
+BM_format_to_string_begin<std::string>/2                              34.0 ns         34.0 ns     20621714 bytes_per_second=56.1704M/s
+BM_format_to_string_begin<std::string>/4                              37.8 ns         37.8 ns     18494368 bytes_per_second=100.897M/s
+BM_format_to_string_begin<std::string>/8                              48.8 ns         48.8 ns     14383142 bytes_per_second=156.493M/s
+BM_format_to_string_begin<std::string>/16                             62.3 ns         62.3 ns     11235179 bytes_per_second=244.784M/s
+BM_format_to_string_begin<std::string>/32                              101 ns          101 ns      6918737 bytes_per_second=302.873M/s
+BM_format_to_string_begin<std::string>/64                              145 ns          145 ns      4821874 bytes_per_second=421.547M/s
+BM_format_to_string_begin<std::string>/128                             262 ns          262 ns      2682037 bytes_per_second=466.604M/s
+BM_format_to_string_begin<std::string>/256                             527 ns          527 ns      1331374 bytes_per_second=463.239M/s
+BM_format_to_string_begin<std::string>/512                             944 ns          944 ns       740446 bytes_per_second=517.091M/s
+BM_format_to_string_begin<std::string>/1024                           1891 ns         1891 ns       370154 bytes_per_second=516.295M/s
+BM_format_to_string_begin<std::string>/2048                           3670 ns         3670 ns       190561 bytes_per_second=532.226M/s
+BM_format_to_string_begin<std::string>/4096                           7325 ns         7325 ns        95597 bytes_per_second=533.253M/s
+BM_format_to_string_begin<std::string>/8192                          14603 ns        14603 ns        47946 bytes_per_second=534.978M/s
+BM_format_to_string_begin<std::string>/16384                         29176 ns        29176 ns        24005 bytes_per_second=535.549M/s
+BM_format_to_string_begin<std::string>/32768                         58302 ns        58303 ns        12005 bytes_per_second=535.997M/s
+BM_format_to_string_begin<std::string>/65536                        116645 ns       116643 ns         5996 bytes_per_second=535.823M/s
+BM_format_to_string_begin<std::string>/131072                       233536 ns       233536 ns         3001 bytes_per_second=535.249M/s
+BM_format_to_string_begin<std::string>/262144                       466762 ns       466763 ns         1500 bytes_per_second=535.604M/s
+BM_format_to_string_begin<std::string>/524288                       932619 ns       932620 ns          751 bytes_per_second=536.124M/s
+BM_format_to_string_begin<std::string>/1048576                     1865487 ns      1865452 ns          375 bytes_per_second=536.063M/s
+BM_format_to_string_begin<std::vector<char>>/1                        32.8 ns         32.8 ns     21288670 bytes_per_second=29.057M/s
+BM_format_to_string_begin<std::vector<char>>/2                        33.9 ns         33.9 ns     20650698 bytes_per_second=56.2919M/s
+BM_format_to_string_begin<std::vector<char>>/4                        38.6 ns         38.6 ns     18125553 bytes_per_second=98.7696M/s
+BM_format_to_string_begin<std::vector<char>>/8                        44.8 ns         44.8 ns     15692791 bytes_per_second=170.343M/s
+BM_format_to_string_begin<std::vector<char>>/16                       58.7 ns         58.7 ns     11928388 bytes_per_second=260.018M/s
+BM_format_to_string_begin<std::vector<char>>/32                       88.8 ns         88.8 ns      7884710 bytes_per_second=343.74M/s
+BM_format_to_string_begin<std::vector<char>>/64                        148 ns          148 ns      4733375 bytes_per_second=412.905M/s
+BM_format_to_string_begin<std::vector<char>>/128                       264 ns          264 ns      2644470 bytes_per_second=462.151M/s
+BM_format_to_string_begin<std::vector<char>>/256                       493 ns          493 ns      1416449 bytes_per_second=495.119M/s
+BM_format_to_string_begin<std::vector<char>>/512                       942 ns          942 ns       741797 bytes_per_second=518.251M/s
+BM_format_to_string_begin<std::vector<char>>/1024                     1892 ns         1892 ns       369918 bytes_per_second=516.078M/s
+BM_format_to_string_begin<std::vector<char>>/2048                     3668 ns         3668 ns       190822 bytes_per_second=532.415M/s
+BM_format_to_string_begin<std::vector<char>>/4096                     7333 ns         7333 ns        95453 bytes_per_second=532.713M/s
+BM_format_to_string_begin<std::vector<char>>/8192                    14619 ns        14619 ns        47912 bytes_per_second=534.394M/s
+BM_format_to_string_begin<std::vector<char>>/16384                   29165 ns        29165 ns        24000 bytes_per_second=535.749M/s
+BM_format_to_string_begin<std::vector<char>>/32768                   58325 ns        58326 ns        12007 bytes_per_second=535.784M/s
+BM_format_to_string_begin<std::vector<char>>/65536                  116615 ns       116614 ns         6003 bytes_per_second=535.958M/s
+BM_format_to_string_begin<std::vector<char>>/131072                 233308 ns       233309 ns         3000 bytes_per_second=535.77M/s
+BM_format_to_string_begin<std::vector<char>>/262144                 466828 ns       466824 ns         1500 bytes_per_second=535.534M/s
+BM_format_to_string_begin<std::vector<char>>/524288                 932480 ns       932480 ns          751 bytes_per_second=536.204M/s
+BM_format_to_string_begin<std::vector<char>>/1048576               1865494 ns      1865482 ns          375 bytes_per_second=536.055M/s
+BM_format_to_string_begin<std::list<char>>/1                          33.7 ns         33.7 ns     20823135 bytes_per_second=28.3406M/s
+BM_format_to_string_begin<std::list<char>>/2                          37.4 ns         37.4 ns     18721533 bytes_per_second=51.0033M/s
+BM_format_to_string_begin<std::list<char>>/4                          44.9 ns         44.9 ns     15594180 bytes_per_second=85.0389M/s
+BM_format_to_string_begin<std::list<char>>/8                          65.3 ns         65.3 ns     10717737 bytes_per_second=116.899M/s
+BM_format_to_string_begin<std::list<char>>/16                         90.0 ns         90.0 ns      7769344 bytes_per_second=169.6M/s
+BM_format_to_string_begin<std::list<char>>/32                          165 ns          165 ns      4250600 bytes_per_second=185.469M/s
+BM_format_to_string_begin<std::list<char>>/64                          312 ns          312 ns      2243934 bytes_per_second=195.788M/s
+BM_format_to_string_begin<std::list<char>>/128                         597 ns          597 ns      1177019 bytes_per_second=204.616M/s
+BM_format_to_string_begin<std::list<char>>/256                        1180 ns         1180 ns       591553 bytes_per_second=206.821M/s
+BM_format_to_string_begin<std::list<char>>/512                        2313 ns         2313 ns       301658 bytes_per_second=211.143M/s
+BM_format_to_string_begin<std::list<char>>/1024                       4637 ns         4637 ns       151015 bytes_per_second=210.592M/s
+BM_format_to_string_begin<std::list<char>>/2048                       9194 ns         9194 ns        76089 bytes_per_second=212.435M/s
+BM_format_to_string_begin<std::list<char>>/4096                      18407 ns        18407 ns        38016 bytes_per_second=212.211M/s
+BM_format_to_string_begin<std::list<char>>/8192                      36841 ns        36841 ns        18993 bytes_per_second=212.061M/s
+BM_format_to_string_begin<std::list<char>>/16384                     73552 ns        73552 ns         9520 bytes_per_second=212.434M/s
+BM_format_to_string_begin<std::list<char>>/32768                    147226 ns       147227 ns         4752 bytes_per_second=212.257M/s
+BM_format_to_string_begin<std::list<char>>/65536                    294597 ns       294594 ns         2377 bytes_per_second=212.156M/s
+BM_format_to_string_begin<std::list<char>>/131072                   592296 ns       592292 ns         1183 bytes_per_second=211.044M/s
+BM_format_to_string_begin<std::list<char>>/262144                  1292045 ns      1292006 ns          540 bytes_per_second=193.498M/s
+BM_format_to_string_begin<std::list<char>>/524288                  2766472 ns      2766354 ns          253 bytes_per_second=180.743M/s
+BM_format_to_string_begin<std::list<char>>/1048576                 5626492 ns      5626181 ns          123 bytes_per_second=177.74M/s
+BM_format_to_string_span<char>/1                                      32.3 ns         32.3 ns     21654174 bytes_per_second=29.488M/s
+BM_format_to_string_span<char>/2                                      33.9 ns         33.9 ns     20620342 bytes_per_second=56.219M/s
+BM_format_to_string_span<char>/4                                      37.8 ns         37.8 ns     18514409 bytes_per_second=100.911M/s
+BM_format_to_string_span<char>/8                                      44.1 ns         44.1 ns     15866852 bytes_per_second=172.963M/s
+BM_format_to_string_span<char>/16                                     66.0 ns         66.0 ns     10643748 bytes_per_second=231.054M/s
+BM_format_to_string_span<char>/32                                     95.9 ns         95.9 ns      7292150 bytes_per_second=318.343M/s
+BM_format_to_string_span<char>/64                                      172 ns          172 ns      4078331 bytes_per_second=355.55M/s
+BM_format_to_string_span<char>/128                                     285 ns          285 ns      2459387 bytes_per_second=428.852M/s
+BM_format_to_string_span<char>/256                                     527 ns          527 ns      1330744 bytes_per_second=463.491M/s
+BM_format_to_string_span<char>/512                                     960 ns          960 ns       730034 bytes_per_second=508.586M/s
+BM_format_to_string_span<char>/1024                                   1891 ns         1891 ns       369974 bytes_per_second=516.432M/s
+BM_format_to_string_span<char>/2048                                   3671 ns         3671 ns       190712 bytes_per_second=532.057M/s
+BM_format_to_string_span<char>/4096                                   7322 ns         7322 ns        95578 bytes_per_second=533.494M/s
+BM_format_to_string_span<char>/8192                                  14606 ns        14606 ns        47945 bytes_per_second=534.899M/s
+BM_format_to_string_span<char>/16384                                 29162 ns        29162 ns        23993 bytes_per_second=535.798M/s
+BM_format_to_string_span<char>/32768                                 58291 ns        58291 ns        11941 bytes_per_second=536.103M/s
+BM_format_to_string_span<char>/65536                                116610 ns       116611 ns         6003 bytes_per_second=535.972M/s
+BM_format_to_string_span<char>/131072                               233572 ns       233573 ns         2997 bytes_per_second=535.165M/s
+BM_format_to_string_span<char>/262144                               466428 ns       466427 ns         1500 bytes_per_second=535.989M/s
+BM_format_to_string_span<char>/524288                               932574 ns       932578 ns          751 bytes_per_second=536.148M/s
+BM_format_to_string_span<char>/1048576                             1864949 ns      1864955 ns          375 bytes_per_second=536.206M/s
+BM_format_to_string_pointer<char>/1                                   32.6 ns         32.6 ns     21497443 bytes_per_second=29.2773M/s
+BM_format_to_string_pointer<char>/2                                   33.8 ns         33.8 ns     20730662 bytes_per_second=56.4577M/s
+BM_format_to_string_pointer<char>/4                                   37.8 ns         37.8 ns     18526287 bytes_per_second=101.027M/s
+BM_format_to_string_pointer<char>/8                                   45.1 ns         45.1 ns     15559883 bytes_per_second=169.03M/s
+BM_format_to_string_pointer<char>/16                                  59.3 ns         59.3 ns     11670940 bytes_per_second=257.322M/s
+BM_format_to_string_pointer<char>/32                                  94.0 ns         94.0 ns      7476786 bytes_per_second=324.738M/s
+BM_format_to_string_pointer<char>/64                                   146 ns          146 ns      4868416 bytes_per_second=417.959M/s
+BM_format_to_string_pointer<char>/128                                  265 ns          265 ns      2644800 bytes_per_second=461.083M/s
+BM_format_to_string_pointer<char>/256                                  527 ns          527 ns      1326562 bytes_per_second=463.39M/s
+BM_format_to_string_pointer<char>/512                                  962 ns          962 ns       728200 bytes_per_second=507.622M/s
+BM_format_to_string_pointer<char>/1024                                1904 ns         1904 ns       367421 bytes_per_second=512.891M/s
+BM_format_to_string_pointer<char>/2048                                3691 ns         3691 ns       188868 bytes_per_second=529.122M/s
+BM_format_to_string_pointer<char>/4096                                7327 ns         7327 ns        95474 bytes_per_second=533.104M/s
+BM_format_to_string_pointer<char>/8192                               14632 ns        14632 ns        47843 bytes_per_second=533.93M/s
+BM_format_to_string_pointer<char>/16384                              29180 ns        29180 ns        23995 bytes_per_second=535.471M/s
+BM_format_to_string_pointer<char>/32768                              58313 ns        58314 ns        12001 bytes_per_second=535.896M/s
+BM_format_to_string_pointer<char>/65536                             116703 ns       116702 ns         5999 bytes_per_second=535.55M/s
+BM_format_to_string_pointer<char>/131072                            233610 ns       233610 ns         2996 bytes_per_second=535.08M/s
+BM_format_to_string_pointer<char>/262144                            466302 ns       466305 ns         1501 bytes_per_second=536.129M/s
+BM_format_to_string_pointer<char>/524288                            932893 ns       932894 ns          751 bytes_per_second=535.966M/s
+BM_format_to_string_pointer<char>/1048576                          1864887 ns      1864888 ns          375 bytes_per_second=536.225M/s
+BM_format_to_string_back_inserter<std::wstring>/1                     38.0 ns         38.0 ns     18419776 bytes_per_second=100.464M/s
+BM_format_to_string_back_inserter<std::wstring>/2                     39.4 ns         39.4 ns     17782104 bytes_per_second=193.737M/s
+BM_format_to_string_back_inserter<std::wstring>/4                     41.5 ns         41.5 ns     16863518 bytes_per_second=367.765M/s
+BM_format_to_string_back_inserter<std::wstring>/8                     66.4 ns         66.4 ns     10548168 bytes_per_second=459.307M/s
+BM_format_to_string_back_inserter<std::wstring>/16                    75.0 ns         75.0 ns      9354776 bytes_per_second=814.051M/s
+BM_format_to_string_back_inserter<std::wstring>/32                    83.0 ns         83.0 ns      8388235 bytes_per_second=1.43656G/s
+BM_format_to_string_back_inserter<std::wstring>/64                     121 ns          121 ns      5783854 bytes_per_second=1.97037G/s
+BM_format_to_string_back_inserter<std::wstring>/128                    213 ns          213 ns      3296876 bytes_per_second=2.24327G/s
+BM_format_to_string_back_inserter<std::wstring>/256                    425 ns          425 ns      1643049 bytes_per_second=2.24242G/s
+BM_format_to_string_back_inserter<std::wstring>/512                    802 ns          802 ns       872608 bytes_per_second=2.37886G/s
+BM_format_to_string_back_inserter<std::wstring>/1024                  1461 ns         1461 ns       477678 bytes_per_second=2.61128G/s
+BM_format_to_string_back_inserter<std::wstring>/2048                  2556 ns         2556 ns       274286 bytes_per_second=2.98507G/s
+BM_format_to_string_back_inserter<std::wstring>/4096                  5089 ns         5089 ns       137233 bytes_per_second=2.99814G/s
+BM_format_to_string_back_inserter<std::wstring>/8192                 10106 ns        10106 ns        68748 bytes_per_second=3.01988G/s
+BM_format_to_string_back_inserter<std::wstring>/16384                20294 ns        20294 ns        34483 bytes_per_second=3.00757G/s
+BM_format_to_string_back_inserter<std::wstring>/32768                42040 ns        42040 ns        16646 bytes_per_second=2.9037G/s
+BM_format_to_string_back_inserter<std::wstring>/65536                86816 ns        86817 ns         8042 bytes_per_second=2.81214G/s
+BM_format_to_string_back_inserter<std::wstring>/131072              171582 ns       171579 ns         4080 bytes_per_second=2.84581G/s
+BM_format_to_string_back_inserter<std::wstring>/262144              850053 ns       850040 ns          825 bytes_per_second=1.14884G/s
+BM_format_to_string_back_inserter<std::wstring>/524288             1375652 ns      1375571 ns          509 bytes_per_second=1.41986G/s
+BM_format_to_string_back_inserter<std::wstring>/1048576            2457750 ns      2457504 ns          285 bytes_per_second=1.58952G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1             54.4 ns         54.4 ns     12920435 bytes_per_second=70.0842M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/2             54.2 ns         54.2 ns     12929074 bytes_per_second=140.688M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/4             56.3 ns         56.3 ns     12381707 bytes_per_second=271.148M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/8             58.9 ns         58.9 ns     11897300 bytes_per_second=518.551M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/16            65.1 ns         65.1 ns     10869455 bytes_per_second=937.966M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/32            79.3 ns         79.3 ns      8855664 bytes_per_second=1.50291G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/64             113 ns          113 ns      6193862 bytes_per_second=2.11028G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/128            195 ns          195 ns      3589357 bytes_per_second=2.44213G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/256            347 ns          347 ns      2015401 bytes_per_second=2.74907G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/512            690 ns          690 ns      1013075 bytes_per_second=2.76409G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1024          1314 ns         1314 ns       532012 bytes_per_second=2.90299G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/2048          2361 ns         2360 ns       296543 bytes_per_second=3.23214G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/4096          4737 ns         4737 ns       147440 bytes_per_second=3.22097G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/8192          9895 ns         9895 ns        70747 bytes_per_second=3.08402G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/16384        19000 ns        19000 ns        36835 bytes_per_second=3.21238G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/32768        39453 ns        39453 ns        17751 bytes_per_second=3.09408G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/65536        81419 ns        81420 ns         8594 bytes_per_second=2.99854G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/131072      160705 ns       160705 ns         4352 bytes_per_second=3.03837G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/262144      326826 ns       326827 ns         2141 bytes_per_second=2.98801G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/524288      670703 ns       670674 ns         1043 bytes_per_second=2.91218G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1048576    1562320 ns      1562282 ns          444 bytes_per_second=2.50035G/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1               50.1 ns         50.1 ns     13957558 bytes_per_second=76.199M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/2               63.2 ns         63.2 ns     11069943 bytes_per_second=120.689M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/4               89.3 ns         89.3 ns      7818927 bytes_per_second=170.793M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/8                157 ns          157 ns      4473727 bytes_per_second=194.936M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/16               302 ns          302 ns      2318028 bytes_per_second=202.307M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/32               592 ns          592 ns      1180155 bytes_per_second=206.074M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/64              1161 ns         1161 ns       601856 bytes_per_second=210.253M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/128             2269 ns         2269 ns       308896 bytes_per_second=215.216M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/256             4488 ns         4489 ns       155949 bytes_per_second=217.568M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/512             8968 ns         8968 ns        78047 bytes_per_second=217.791M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1024           18032 ns        18032 ns        38846 bytes_per_second=216.626M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/2048           36053 ns        36053 ns        19419 bytes_per_second=216.693M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/4096           72355 ns        72355 ns         9670 bytes_per_second=215.948M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/8192          145517 ns       145518 ns         4807 bytes_per_second=214.751M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/16384         291358 ns       291359 ns         2401 bytes_per_second=214.512M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/32768         583789 ns       583792 ns         1192 bytes_per_second=214.117M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/65536        1167908 ns      1167871 ns          596 bytes_per_second=214.065M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/131072       2350291 ns      2350280 ns          296 bytes_per_second=212.741M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/262144       4922167 ns      4921907 ns          131 bytes_per_second=203.173M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/524288      10138047 ns     10137702 ns           64 bytes_per_second=197.283M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1048576     20626861 ns     20626116 ns           32 bytes_per_second=193.929M/s
+BM_format_to_string_begin<std::wstring>/1                             32.1 ns         32.1 ns     21740854 bytes_per_second=118.777M/s
+BM_format_to_string_begin<std::wstring>/2                             32.9 ns         32.9 ns     21257009 bytes_per_second=231.719M/s
+BM_format_to_string_begin<std::wstring>/4                             34.7 ns         34.7 ns     20169543 bytes_per_second=439.447M/s
+BM_format_to_string_begin<std::wstring>/8                             37.2 ns         37.2 ns     18801422 bytes_per_second=819.449M/s
+BM_format_to_string_begin<std::wstring>/16                            42.8 ns         42.8 ns     16337599 bytes_per_second=1.39103G/s
+BM_format_to_string_begin<std::wstring>/32                            56.4 ns         56.4 ns     12399188 bytes_per_second=2.11208G/s
+BM_format_to_string_begin<std::wstring>/64                            86.7 ns         86.7 ns      8069545 bytes_per_second=2.75096G/s
+BM_format_to_string_begin<std::wstring>/128                            130 ns          130 ns      5392023 bytes_per_second=3.67634G/s
+BM_format_to_string_begin<std::wstring>/256                            225 ns          225 ns      3113436 bytes_per_second=4.24107G/s
+BM_format_to_string_begin<std::wstring>/512                            406 ns          406 ns      1722615 bytes_per_second=4.69328G/s
+BM_format_to_string_begin<std::wstring>/1024                           762 ns          762 ns       916818 bytes_per_second=5.0032G/s
+BM_format_to_string_begin<std::wstring>/2048                          1551 ns         1551 ns       451326 bytes_per_second=4.91814G/s
+BM_format_to_string_begin<std::wstring>/4096                          3039 ns         3039 ns       229895 bytes_per_second=5.02073G/s
+BM_format_to_string_begin<std::wstring>/8192                          7821 ns         7821 ns        89398 bytes_per_second=3.90195G/s
+BM_format_to_string_begin<std::wstring>/16384                        14670 ns        14670 ns        47769 bytes_per_second=4.16055G/s
+BM_format_to_string_begin<std::wstring>/32768                        31743 ns        31743 ns        22062 bytes_per_second=3.84561G/s
+BM_format_to_string_begin<std::wstring>/65536                        65248 ns        65248 ns        10721 bytes_per_second=3.74173G/s
+BM_format_to_string_begin<std::wstring>/131072                      130353 ns       130354 ns         5370 bytes_per_second=3.74582G/s
+BM_format_to_string_begin<std::wstring>/262144                      260326 ns       260326 ns         2689 bytes_per_second=3.75131G/s
+BM_format_to_string_begin<std::wstring>/524288                      520975 ns       520962 ns         1343 bytes_per_second=3.74908G/s
+BM_format_to_string_begin<std::wstring>/1048576                    1095343 ns      1095310 ns          636 bytes_per_second=3.56634G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1                     32.1 ns         32.1 ns     21810682 bytes_per_second=118.822M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/2                     33.0 ns         33.0 ns     21209896 bytes_per_second=231.256M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/4                     34.3 ns         34.3 ns     20423331 bytes_per_second=445.215M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/8                     37.1 ns         37.1 ns     18844899 bytes_per_second=821.49M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/16                    42.7 ns         42.7 ns     16395689 bytes_per_second=1.3963G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/32                    54.0 ns         54.0 ns     12925541 bytes_per_second=2.20862G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/64                    84.0 ns         84.0 ns      8339002 bytes_per_second=2.83903G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/128                    130 ns          130 ns      5402566 bytes_per_second=3.67922G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/256                    226 ns          226 ns      3101697 bytes_per_second=4.22601G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/512                    407 ns          407 ns      1720185 bytes_per_second=4.68713G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1024                   762 ns          762 ns       918700 bytes_per_second=5.00724G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/2048                  1554 ns         1554 ns       450641 bytes_per_second=4.90907G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/4096                  3043 ns         3043 ns       229578 bytes_per_second=5.01359G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/8192                  7817 ns         7817 ns        89576 bytes_per_second=3.90403G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/16384                14657 ns        14657 ns        47716 bytes_per_second=4.16419G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/32768                31715 ns        31715 ns        22059 bytes_per_second=3.84892G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/65536                65247 ns        65247 ns        10735 bytes_per_second=3.74177G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/131072              130343 ns       130343 ns         5362 bytes_per_second=3.74612G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/262144              262701 ns       262575 ns         2689 bytes_per_second=3.71918G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/524288              547882 ns       547870 ns         1278 bytes_per_second=3.56494G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1048576            1143993 ns      1143973 ns          610 bytes_per_second=3.41463G/s
+BM_format_to_string_begin<std::list<wchar_t>>/1                       33.3 ns         33.3 ns     20998562 bytes_per_second=114.391M/s
+BM_format_to_string_begin<std::list<wchar_t>>/2                       36.0 ns         36.0 ns     19419107 bytes_per_second=211.667M/s
+BM_format_to_string_begin<std::list<wchar_t>>/4                       42.2 ns         42.2 ns     16589352 bytes_per_second=361.214M/s
+BM_format_to_string_begin<std::list<wchar_t>>/8                       56.6 ns         56.6 ns     12374371 bytes_per_second=539.202M/s
+BM_format_to_string_begin<std::list<wchar_t>>/16                      80.9 ns         80.9 ns      8655229 bytes_per_second=754.567M/s
+BM_format_to_string_begin<std::list<wchar_t>>/32                       135 ns          135 ns      5186731 bytes_per_second=904.11M/s
+BM_format_to_string_begin<std::list<wchar_t>>/64                       245 ns          245 ns      2860125 bytes_per_second=997.628M/s
+BM_format_to_string_begin<std::list<wchar_t>>/128                      462 ns          462 ns      1515187 bytes_per_second=1057.55M/s
+BM_format_to_string_begin<std::list<wchar_t>>/256                      897 ns          897 ns       779486 bytes_per_second=1088.88M/s
+BM_format_to_string_begin<std::list<wchar_t>>/512                     1756 ns         1756 ns       398725 bytes_per_second=1112.36M/s
+BM_format_to_string_begin<std::list<wchar_t>>/1024                    3519 ns         3519 ns       198618 bytes_per_second=1110.1M/s
+BM_format_to_string_begin<std::list<wchar_t>>/2048                    7039 ns         7039 ns        99385 bytes_per_second=1109.9M/s
+BM_format_to_string_begin<std::list<wchar_t>>/4096                   14004 ns        14004 ns        50002 bytes_per_second=1115.76M/s
+BM_format_to_string_begin<std::list<wchar_t>>/8192                   28015 ns        28014 ns        25009 bytes_per_second=1115.5M/s
+BM_format_to_string_begin<std::list<wchar_t>>/16384                  56043 ns        56043 ns        12496 bytes_per_second=1115.21M/s
+BM_format_to_string_begin<std::list<wchar_t>>/32768                 111868 ns       111867 ns         6258 bytes_per_second=1117.39M/s
+BM_format_to_string_begin<std::list<wchar_t>>/65536                 223394 ns       223394 ns         3133 bytes_per_second=1119.1M/s
+BM_format_to_string_begin<std::list<wchar_t>>/131072                447283 ns       447276 ns         1564 bytes_per_second=1117.88M/s
+BM_format_to_string_begin<std::list<wchar_t>>/262144               1019951 ns      1019916 ns          688 bytes_per_second=980.473M/s
+BM_format_to_string_begin<std::list<wchar_t>>/524288               2190015 ns      2189938 ns          319 bytes_per_second=913.268M/s
+BM_format_to_string_begin<std::list<wchar_t>>/1048576              4510980 ns      4510878 ns          155 bytes_per_second=886.745M/s
+BM_format_to_string_span<wchar_t>/1                                   32.1 ns         32.1 ns     21831371 bytes_per_second=118.943M/s
+BM_format_to_string_span<wchar_t>/2                                   33.2 ns         33.2 ns     21091011 bytes_per_second=229.799M/s
+BM_format_to_string_span<wchar_t>/4                                   34.5 ns         34.5 ns     20296473 bytes_per_second=442.612M/s
+BM_format_to_string_span<wchar_t>/8                                   37.5 ns         37.5 ns     18663908 bytes_per_second=814.38M/s
+BM_format_to_string_span<wchar_t>/16                                  43.0 ns         43.0 ns     16286528 bytes_per_second=1.38709G/s
+BM_format_to_string_span<wchar_t>/32                                  56.5 ns         56.5 ns     12370337 bytes_per_second=2.10966G/s
+BM_format_to_string_span<wchar_t>/64                                  85.9 ns         85.9 ns      8162409 bytes_per_second=2.77667G/s
+BM_format_to_string_span<wchar_t>/128                                  129 ns          129 ns      5411117 bytes_per_second=3.68636G/s
+BM_format_to_string_span<wchar_t>/256                                  223 ns          223 ns      3133724 bytes_per_second=4.26732G/s
+BM_format_to_string_span<wchar_t>/512                                  399 ns          399 ns      1753197 bytes_per_second=4.77596G/s
+BM_format_to_string_span<wchar_t>/1024                                 745 ns          745 ns       940246 bytes_per_second=5.12324G/s
+BM_format_to_string_span<wchar_t>/2048                                1564 ns         1564 ns       446986 bytes_per_second=4.8787G/s
+BM_format_to_string_span<wchar_t>/4096                                2989 ns         2989 ns       234245 bytes_per_second=5.10546G/s
+BM_format_to_string_span<wchar_t>/8192                                7768 ns         7768 ns        89978 bytes_per_second=3.92841G/s
+BM_format_to_string_span<wchar_t>/16384                              14405 ns        14405 ns        48528 bytes_per_second=4.23719G/s
+BM_format_to_string_span<wchar_t>/32768                              31831 ns        31831 ns        22009 bytes_per_second=3.83497G/s
+BM_format_to_string_span<wchar_t>/65536                              64938 ns        64938 ns        10743 bytes_per_second=3.75962G/s
+BM_format_to_string_span<wchar_t>/131072                            129980 ns       129978 ns         5389 bytes_per_second=3.75664G/s
+BM_format_to_string_span<wchar_t>/262144                            259928 ns       259928 ns         2692 bytes_per_second=3.75705G/s
+BM_format_to_string_span<wchar_t>/524288                            522127 ns       522123 ns         1341 bytes_per_second=3.74074G/s
+BM_format_to_string_span<wchar_t>/1048576                          1092979 ns      1092947 ns          642 bytes_per_second=3.57405G/s
+BM_format_to_string_pointer<wchar_t>/1                                32.6 ns         32.6 ns     21451473 bytes_per_second=117.177M/s
+BM_format_to_string_pointer<wchar_t>/2                                33.4 ns         33.4 ns     20991088 bytes_per_second=228.678M/s
+BM_format_to_string_pointer<wchar_t>/4                                34.9 ns         34.9 ns     20038644 bytes_per_second=436.988M/s
+BM_format_to_string_pointer<wchar_t>/8                                37.6 ns         37.6 ns     18588875 bytes_per_second=810.892M/s
+BM_format_to_string_pointer<wchar_t>/16                               43.1 ns         43.1 ns     16242638 bytes_per_second=1.38294G/s
+BM_format_to_string_pointer<wchar_t>/32                               56.4 ns         56.4 ns     12421113 bytes_per_second=2.11454G/s
+BM_format_to_string_pointer<wchar_t>/64                               83.9 ns         83.9 ns      8341412 bytes_per_second=2.84075G/s
+BM_format_to_string_pointer<wchar_t>/128                               129 ns          129 ns      5441756 bytes_per_second=3.70381G/s
+BM_format_to_string_pointer<wchar_t>/256                               223 ns          223 ns      3141084 bytes_per_second=4.28079G/s
+BM_format_to_string_pointer<wchar_t>/512                               405 ns          405 ns      1730174 bytes_per_second=4.71433G/s
+BM_format_to_string_pointer<wchar_t>/1024                              759 ns          759 ns       922155 bytes_per_second=5.02474G/s
+BM_format_to_string_pointer<wchar_t>/2048                             1550 ns         1550 ns       451123 bytes_per_second=4.92349G/s
+BM_format_to_string_pointer<wchar_t>/4096                             3044 ns         3044 ns       230047 bytes_per_second=5.01354G/s
+BM_format_to_string_pointer<wchar_t>/8192                             7800 ns         7800 ns        89815 bytes_per_second=3.91228G/s
+BM_format_to_string_pointer<wchar_t>/16384                           14672 ns        14672 ns        47732 bytes_per_second=4.15984G/s
+BM_format_to_string_pointer<wchar_t>/32768                           31973 ns        31973 ns        21876 bytes_per_second=3.81786G/s
+BM_format_to_string_pointer<wchar_t>/65536                           65066 ns        65066 ns        10740 bytes_per_second=3.75218G/s
+BM_format_to_string_pointer<wchar_t>/131072                         130161 ns       130162 ns         5377 bytes_per_second=3.75134G/s
+BM_format_to_string_pointer<wchar_t>/262144                         260112 ns       260112 ns         2690 bytes_per_second=3.75439G/s
+BM_format_to_string_pointer<wchar_t>/524288                         521888 ns       521887 ns         1338 bytes_per_second=3.74243G/s
+BM_format_to_string_pointer<wchar_t>/1048576                       1095014 ns      1094984 ns          637 bytes_per_second=3.5674G/s

libcxx/after-v2/format_to_n.txt

+----------------------------------------------------------------------------------------------------------------------------
+Benchmark                                                                  Time             CPU   Iterations UserCounters...
+----------------------------------------------------------------------------------------------------------------------------
+BM_format_to_n_string_back_inserter<std::string>/1                      48.0 ns         48.0 ns     14577751 bytes_per_second=19.8664M/s
+BM_format_to_n_string_back_inserter<std::string>/2                      50.2 ns         50.2 ns     13970174 bytes_per_second=37.9704M/s
+BM_format_to_n_string_back_inserter<std::string>/4                      58.7 ns         58.7 ns     11932928 bytes_per_second=64.9998M/s
+BM_format_to_n_string_back_inserter<std::string>/8                      69.3 ns         69.3 ns     10108927 bytes_per_second=110.118M/s
+BM_format_to_n_string_back_inserter<std::string>/16                     96.6 ns         96.6 ns      7251680 bytes_per_second=157.997M/s
+BM_format_to_n_string_back_inserter<std::string>/32                      178 ns          178 ns      3898809 bytes_per_second=171.106M/s
+BM_format_to_n_string_back_inserter<std::string>/64                      292 ns          292 ns      2397794 bytes_per_second=209.126M/s
+BM_format_to_n_string_back_inserter<std::string>/128                     535 ns          535 ns      1308875 bytes_per_second=228.063M/s
+BM_format_to_n_string_back_inserter<std::string>/256                    1007 ns         1007 ns       694140 bytes_per_second=242.49M/s
+BM_format_to_n_string_back_inserter<std::string>/512                    1968 ns         1969 ns       355465 bytes_per_second=248.044M/s
+BM_format_to_n_string_back_inserter<std::string>/1024                   3941 ns         3941 ns       177627 bytes_per_second=247.786M/s
+BM_format_to_n_string_back_inserter<std::string>/2048                   7833 ns         7833 ns        89464 bytes_per_second=249.336M/s
+BM_format_to_n_string_back_inserter<std::string>/4096                  15507 ns        15506 ns        45167 bytes_per_second=251.915M/s
+BM_format_to_n_string_back_inserter<std::string>/8192                  30754 ns        30755 ns        22744 bytes_per_second=254.023M/s
+BM_format_to_n_string_back_inserter<std::string>/16384                 61051 ns        61053 ns        11466 bytes_per_second=255.924M/s
+BM_format_to_n_string_back_inserter<std::string>/32768                121800 ns       121804 ns         5745 bytes_per_second=256.56M/s
+BM_format_to_n_string_back_inserter<std::string>/65536                244750 ns       244758 ns         2857 bytes_per_second=255.355M/s
+BM_format_to_n_string_back_inserter<std::string>/131072               489562 ns       489577 ns         1429 bytes_per_second=255.323M/s
+BM_format_to_n_string_back_inserter<std::string>/262144               978459 ns       978468 ns          715 bytes_per_second=255.501M/s
+BM_format_to_n_string_back_inserter<std::string>/524288              1955016 ns      1955021 ns          358 bytes_per_second=255.752M/s
+BM_format_to_n_string_back_inserter<std::string>/1048576             3932414 ns      3932543 ns          178 bytes_per_second=254.288M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1                61.0 ns         61.0 ns     11369911 bytes_per_second=15.6407M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/2                63.1 ns         63.1 ns     11091954 bytes_per_second=30.2461M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/4                70.7 ns         70.8 ns      9956100 bytes_per_second=53.9172M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/8                82.4 ns         82.4 ns      8509373 bytes_per_second=92.6241M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/16                110 ns          110 ns      6349272 bytes_per_second=138.774M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/32                178 ns          178 ns      3970934 bytes_per_second=171.497M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/64                286 ns          286 ns      2502483 bytes_per_second=213.21M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/128               529 ns          529 ns      1326727 bytes_per_second=230.738M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/256               995 ns          995 ns       705145 bytes_per_second=245.307M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/512              1982 ns         1982 ns       353343 bytes_per_second=246.346M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1024             3855 ns         3855 ns       181784 bytes_per_second=253.347M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/2048             7698 ns         7698 ns        90925 bytes_per_second=253.71M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/4096            15304 ns        15304 ns        45712 bytes_per_second=255.241M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/8192            30519 ns        30520 ns        22945 bytes_per_second=255.982M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/16384           60735 ns        60735 ns        11524 bytes_per_second=257.267M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/32768          121214 ns       121218 ns         5765 bytes_per_second=257.8M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/65536          243093 ns       243101 ns         2880 bytes_per_second=257.095M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/131072         486071 ns       486087 ns         1440 bytes_per_second=257.156M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/262144         973859 ns       973852 ns          718 bytes_per_second=256.712M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/524288        1945472 ns      1945477 ns          360 bytes_per_second=257.006M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1048576       3900917 ns      3901044 ns          179 bytes_per_second=256.342M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1                  57.7 ns         57.7 ns     12143867 bytes_per_second=16.5151M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/2                  71.7 ns         71.7 ns      9748500 bytes_per_second=26.6009M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/4                   104 ns          104 ns      6736904 bytes_per_second=36.8551M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/8                   178 ns          178 ns      4000319 bytes_per_second=42.7803M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/16                  360 ns          360 ns      1954188 bytes_per_second=42.344M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/32                  697 ns          697 ns      1009057 bytes_per_second=43.8075M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/64                 1325 ns         1325 ns       519370 bytes_per_second=46.0523M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/128                2622 ns         2622 ns       266332 bytes_per_second=46.5592M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/256                5192 ns         5192 ns       134172 bytes_per_second=47.0197M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/512               10431 ns        10431 ns        67162 bytes_per_second=46.8085M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1024              20881 ns        20881 ns        33513 bytes_per_second=46.7689M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/2048              41625 ns        41627 ns        16816 bytes_per_second=46.9201M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/4096              83322 ns        83325 ns         8402 bytes_per_second=46.8797M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/8192             166865 ns       166870 ns         4193 bytes_per_second=46.8178M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/16384            334582 ns       334586 ns         2092 bytes_per_second=46.6995M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/32768            669191 ns       669210 ns         1041 bytes_per_second=46.6968M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/65536           1338874 ns      1338917 ns          518 bytes_per_second=46.6795M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/131072          2689778 ns      2689751 ns          259 bytes_per_second=46.4727M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/262144          5498488 ns      5498466 ns          118 bytes_per_second=45.4672M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/524288         11161100 ns     11160897 ns           59 bytes_per_second=44.7993M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1048576        22635985 ns     22636482 ns           29 bytes_per_second=44.1765M/s
+BM_format_to_n_string_begin<std::string>/1                              39.7 ns         39.7 ns     17641605 bytes_per_second=24.0337M/s
+BM_format_to_n_string_begin<std::string>/2                              44.2 ns         44.2 ns     15920621 bytes_per_second=43.1596M/s
+BM_format_to_n_string_begin<std::string>/4                              50.0 ns         50.0 ns     14078057 bytes_per_second=76.223M/s
+BM_format_to_n_string_begin<std::string>/8                              56.7 ns         56.7 ns     12634024 bytes_per_second=134.642M/s
+BM_format_to_n_string_begin<std::string>/16                             80.9 ns         80.9 ns      8641939 bytes_per_second=188.549M/s
+BM_format_to_n_string_begin<std::string>/32                              153 ns          153 ns      4567955 bytes_per_second=199.74M/s
+BM_format_to_n_string_begin<std::string>/64                              270 ns          270 ns      2592987 bytes_per_second=226.062M/s
+BM_format_to_n_string_begin<std::string>/128                             499 ns          499 ns      1402324 bytes_per_second=244.487M/s
+BM_format_to_n_string_begin<std::string>/256                             978 ns          978 ns       716175 bytes_per_second=249.739M/s
+BM_format_to_n_string_begin<std::string>/512                            1892 ns         1892 ns       369976 bytes_per_second=258.09M/s
+BM_format_to_n_string_begin<std::string>/1024                           3729 ns         3729 ns       187805 bytes_per_second=261.881M/s
+BM_format_to_n_string_begin<std::string>/2048                           7387 ns         7387 ns        94805 bytes_per_second=264.408M/s
+BM_format_to_n_string_begin<std::string>/4096                          14733 ns        14733 ns        47518 bytes_per_second=265.132M/s
+BM_format_to_n_string_begin<std::string>/8192                          29392 ns        29393 ns        23811 bytes_per_second=265.797M/s
+BM_format_to_n_string_begin<std::string>/16384                         59108 ns        59110 ns        11760 bytes_per_second=264.34M/s
+BM_format_to_n_string_begin<std::string>/32768                        118228 ns       118228 ns         5922 bytes_per_second=264.321M/s
+BM_format_to_n_string_begin<std::string>/65536                        236047 ns       236055 ns         2967 bytes_per_second=264.769M/s
+BM_format_to_n_string_begin<std::string>/131072                       471678 ns       471693 ns         1483 bytes_per_second=265.003M/s
+BM_format_to_n_string_begin<std::string>/262144                       944375 ns       944402 ns          741 bytes_per_second=264.718M/s
+BM_format_to_n_string_begin<std::string>/524288                      1887868 ns      1887919 ns          371 bytes_per_second=264.842M/s
+BM_format_to_n_string_begin<std::string>/1048576                     3776217 ns      3776261 ns          185 bytes_per_second=264.812M/s
+BM_format_to_n_string_begin<std::vector<char>>/1                        39.7 ns         39.7 ns     17644336 bytes_per_second=24.033M/s
+BM_format_to_n_string_begin<std::vector<char>>/2                        43.2 ns         43.2 ns     16286188 bytes_per_second=44.1704M/s
+BM_format_to_n_string_begin<std::vector<char>>/4                        49.4 ns         49.4 ns     14036096 bytes_per_second=77.2555M/s
+BM_format_to_n_string_begin<std::vector<char>>/8                        63.5 ns         63.5 ns     10989033 bytes_per_second=120.141M/s
+BM_format_to_n_string_begin<std::vector<char>>/16                       81.4 ns         81.4 ns      8537047 bytes_per_second=187.37M/s
+BM_format_to_n_string_begin<std::vector<char>>/32                        142 ns          142 ns      5158563 bytes_per_second=215.254M/s
+BM_format_to_n_string_begin<std::vector<char>>/64                        272 ns          272 ns      2576569 bytes_per_second=224.627M/s
+BM_format_to_n_string_begin<std::vector<char>>/128                       503 ns          503 ns      1391852 bytes_per_second=242.59M/s
+BM_format_to_n_string_begin<std::vector<char>>/256                       978 ns          978 ns       716149 bytes_per_second=249.568M/s
+BM_format_to_n_string_begin<std::vector<char>>/512                      1894 ns         1894 ns       369779 bytes_per_second=257.797M/s
+BM_format_to_n_string_begin<std::vector<char>>/1024                     3750 ns         3750 ns       187771 bytes_per_second=260.411M/s
+BM_format_to_n_string_begin<std::vector<char>>/2048                     7386 ns         7387 ns        94733 bytes_per_second=264.417M/s
+BM_format_to_n_string_begin<std::vector<char>>/4096                    14734 ns        14734 ns        47341 bytes_per_second=265.112M/s
+BM_format_to_n_string_begin<std::vector<char>>/8192                    29393 ns        29394 ns        23794 bytes_per_second=265.788M/s
+BM_format_to_n_string_begin<std::vector<char>>/16384                   59108 ns        59109 ns        11851 bytes_per_second=264.341M/s
+BM_format_to_n_string_begin<std::vector<char>>/32768                  118258 ns       118261 ns         5924 bytes_per_second=264.246M/s
+BM_format_to_n_string_begin<std::vector<char>>/65536                  236030 ns       236038 ns         2965 bytes_per_second=264.788M/s
+BM_format_to_n_string_begin<std::vector<char>>/131072                 471872 ns       471869 ns         1483 bytes_per_second=264.904M/s
+BM_format_to_n_string_begin<std::vector<char>>/262144                 944542 ns       944572 ns          741 bytes_per_second=264.67M/s
+BM_format_to_n_string_begin<std::vector<char>>/524288                1888050 ns      1888100 ns          371 bytes_per_second=264.817M/s
+BM_format_to_n_string_begin<std::vector<char>>/1048576               3775616 ns      3775727 ns          185 bytes_per_second=264.85M/s
+BM_format_to_n_string_begin<std::list<char>>/1                          40.3 ns         40.3 ns     17379091 bytes_per_second=23.6694M/s
+BM_format_to_n_string_begin<std::list<char>>/2                          43.9 ns         43.9 ns     15946552 bytes_per_second=43.4693M/s
+BM_format_to_n_string_begin<std::list<char>>/4                          51.9 ns         51.9 ns     13487424 bytes_per_second=73.5031M/s
+BM_format_to_n_string_begin<std::list<char>>/8                          73.3 ns         73.3 ns      9215691 bytes_per_second=104.12M/s
+BM_format_to_n_string_begin<std::list<char>>/16                          121 ns          121 ns      5778434 bytes_per_second=126.08M/s
+BM_format_to_n_string_begin<std::list<char>>/32                          224 ns          224 ns      3143133 bytes_per_second=135.977M/s
+BM_format_to_n_string_begin<std::list<char>>/64                          420 ns          420 ns      1666379 bytes_per_second=145.231M/s
+BM_format_to_n_string_begin<std::list<char>>/128                         855 ns          855 ns       833799 bytes_per_second=142.73M/s
+BM_format_to_n_string_begin<std::list<char>>/256                        1652 ns         1652 ns       420409 bytes_per_second=147.823M/s
+BM_format_to_n_string_begin<std::list<char>>/512                        3325 ns         3325 ns       210646 bytes_per_second=146.845M/s
+BM_format_to_n_string_begin<std::list<char>>/1024                       6638 ns         6638 ns       105064 bytes_per_second=147.113M/s
+BM_format_to_n_string_begin<std::list<char>>/2048                      13186 ns        13187 ns        53142 bytes_per_second=148.112M/s
+BM_format_to_n_string_begin<std::list<char>>/4096                      26288 ns        26288 ns        26631 bytes_per_second=148.597M/s
+BM_format_to_n_string_begin<std::list<char>>/8192                      52507 ns        52509 ns        13339 bytes_per_second=148.785M/s
+BM_format_to_n_string_begin<std::list<char>>/16384                    104979 ns       104982 ns         6667 bytes_per_second=148.835M/s
+BM_format_to_n_string_begin<std::list<char>>/32768                    210005 ns       210011 ns         3337 bytes_per_second=148.801M/s
+BM_format_to_n_string_begin<std::list<char>>/65536                    419647 ns       419661 ns         1669 bytes_per_second=148.93M/s
+BM_format_to_n_string_begin<std::list<char>>/131072                   844545 ns       844572 ns          828 bytes_per_second=148.004M/s
+BM_format_to_n_string_begin<std::list<char>>/262144                  1799686 ns      1799569 ns          389 bytes_per_second=138.922M/s
+BM_format_to_n_string_begin<std::list<char>>/524288                  3789620 ns      3789380 ns          185 bytes_per_second=131.948M/s
+BM_format_to_n_string_begin<std::list<char>>/1048576                 7645913 ns      7645528 ns           92 bytes_per_second=130.795M/s
+BM_format_to_n_string_span<char>/1                                      39.6 ns         39.6 ns     17696577 bytes_per_second=24.1071M/s
+BM_format_to_n_string_span<char>/2                                      43.0 ns         43.0 ns     16492294 bytes_per_second=44.3735M/s
+BM_format_to_n_string_span<char>/4                                      50.5 ns         50.5 ns     13861445 bytes_per_second=75.6061M/s
+BM_format_to_n_string_span<char>/8                                      62.5 ns         62.5 ns     11248947 bytes_per_second=122.08M/s
+BM_format_to_n_string_span<char>/16                                     85.3 ns         85.3 ns      8192995 bytes_per_second=178.901M/s
+BM_format_to_n_string_span<char>/32                                      136 ns          136 ns      5141155 bytes_per_second=224.068M/s
+BM_format_to_n_string_span<char>/64                                      270 ns          270 ns      2586355 bytes_per_second=225.658M/s
+BM_format_to_n_string_span<char>/128                                     500 ns          500 ns      1399883 bytes_per_second=243.989M/s
+BM_format_to_n_string_span<char>/256                                     977 ns          977 ns       715951 bytes_per_second=249.816M/s
+BM_format_to_n_string_span<char>/512                                    1893 ns         1893 ns       370024 bytes_per_second=257.97M/s
+BM_format_to_n_string_span<char>/1024                                   3729 ns         3729 ns       187721 bytes_per_second=261.897M/s
+BM_format_to_n_string_span<char>/2048                                   7389 ns         7389 ns        94836 bytes_per_second=264.318M/s
+BM_format_to_n_string_span<char>/4096                                  14736 ns        14735 ns        47482 bytes_per_second=265.093M/s
+BM_format_to_n_string_span<char>/8192                                  29400 ns        29400 ns        23813 bytes_per_second=265.728M/s
+BM_format_to_n_string_span<char>/16384                                 59105 ns        59104 ns        11848 bytes_per_second=264.363M/s
+BM_format_to_n_string_span<char>/32768                                118251 ns       118252 ns         5926 bytes_per_second=264.266M/s
+BM_format_to_n_string_span<char>/65536                                236152 ns       236146 ns         2967 bytes_per_second=264.667M/s
+BM_format_to_n_string_span<char>/131072                               472175 ns       472178 ns         1482 bytes_per_second=264.731M/s
+BM_format_to_n_string_span<char>/262144                               944506 ns       944507 ns          741 bytes_per_second=264.688M/s
+BM_format_to_n_string_span<char>/524288                              1887993 ns      1887982 ns          371 bytes_per_second=264.833M/s
+BM_format_to_n_string_span<char>/1048576                             3775601 ns      3775586 ns          185 bytes_per_second=264.86M/s
+BM_format_to_n_string_pointer<char>/1                                   39.6 ns         39.6 ns     17680788 bytes_per_second=24.0822M/s
+BM_format_to_n_string_pointer<char>/2                                   43.0 ns         43.0 ns     16332095 bytes_per_second=44.3063M/s
+BM_format_to_n_string_pointer<char>/4                                   49.7 ns         49.7 ns     14071148 bytes_per_second=76.7004M/s
+BM_format_to_n_string_pointer<char>/8                                   66.0 ns         66.0 ns     10619536 bytes_per_second=115.541M/s
+BM_format_to_n_string_pointer<char>/16                                  85.7 ns         85.7 ns      8246325 bytes_per_second=178.061M/s
+BM_format_to_n_string_pointer<char>/32                                   136 ns          136 ns      5129247 bytes_per_second=223.671M/s
+BM_format_to_n_string_pointer<char>/64                                   274 ns          274 ns      2561199 bytes_per_second=223.126M/s
+BM_format_to_n_string_pointer<char>/128                                  507 ns          507 ns      1385644 bytes_per_second=240.956M/s
+BM_format_to_n_string_pointer<char>/256                                  977 ns          977 ns       715752 bytes_per_second=249.954M/s
+BM_format_to_n_string_pointer<char>/512                                 1891 ns         1891 ns       370268 bytes_per_second=258.269M/s
+BM_format_to_n_string_pointer<char>/1024                                3725 ns         3725 ns       188001 bytes_per_second=262.169M/s
+BM_format_to_n_string_pointer<char>/2048                                7385 ns         7385 ns        94777 bytes_per_second=264.472M/s
+BM_format_to_n_string_pointer<char>/4096                               14728 ns        14728 ns        47508 bytes_per_second=265.233M/s
+BM_format_to_n_string_pointer<char>/8192                               29401 ns        29401 ns        23780 bytes_per_second=265.724M/s
+BM_format_to_n_string_pointer<char>/16384                              59740 ns        59740 ns        11787 bytes_per_second=261.549M/s
+BM_format_to_n_string_pointer<char>/32768                             119647 ns       119647 ns         5835 bytes_per_second=261.185M/s
+BM_format_to_n_string_pointer<char>/65536                             238928 ns       238925 ns         2927 bytes_per_second=261.589M/s
+BM_format_to_n_string_pointer<char>/131072                            478268 ns       478269 ns         1463 bytes_per_second=261.359M/s
+BM_format_to_n_string_pointer<char>/262144                            956928 ns       956935 ns          732 bytes_per_second=261.251M/s
+BM_format_to_n_string_pointer<char>/524288                           1913400 ns      1913411 ns          366 bytes_per_second=261.313M/s
+BM_format_to_n_string_pointer<char>/1048576                          3818215 ns      3818220 ns          183 bytes_per_second=261.902M/s
+BM_format_to_n_string_back_inserter<std::wstring>/1                     44.6 ns         44.6 ns     15675018 bytes_per_second=85.4462M/s
+BM_format_to_n_string_back_inserter<std::wstring>/2                     46.3 ns         46.3 ns     15126673 bytes_per_second=164.916M/s
+BM_format_to_n_string_back_inserter<std::wstring>/4                     49.7 ns         49.7 ns     14090245 bytes_per_second=306.969M/s
+BM_format_to_n_string_back_inserter<std::wstring>/8                     77.5 ns         77.5 ns      9045656 bytes_per_second=393.963M/s
+BM_format_to_n_string_back_inserter<std::wstring>/16                    92.9 ns         92.9 ns      7552741 bytes_per_second=656.686M/s
+BM_format_to_n_string_back_inserter<std::wstring>/32                     121 ns          121 ns      5805757 bytes_per_second=1011.99M/s
+BM_format_to_n_string_back_inserter<std::wstring>/64                     183 ns          183 ns      3835045 bytes_per_second=1.30338G/s
+BM_format_to_n_string_back_inserter<std::wstring>/128                    333 ns          333 ns      2105911 bytes_per_second=1.43314G/s
+BM_format_to_n_string_back_inserter<std::wstring>/256                    670 ns          670 ns      1042249 bytes_per_second=1.42307G/s
+BM_format_to_n_string_back_inserter<std::wstring>/512                   1263 ns         1263 ns       554146 bytes_per_second=1.50965G/s
+BM_format_to_n_string_back_inserter<std::wstring>/1024                  2373 ns         2373 ns       295069 bytes_per_second=1.60778G/s
+BM_format_to_n_string_back_inserter<std::wstring>/2048                  4541 ns         4541 ns       154101 bytes_per_second=1.68002G/s
+BM_format_to_n_string_back_inserter<std::wstring>/4096                  8732 ns         8732 ns        79892 bytes_per_second=1.7474G/s
+BM_format_to_n_string_back_inserter<std::wstring>/8192                 17209 ns        17209 ns        40665 bytes_per_second=1.77335G/s
+BM_format_to_n_string_back_inserter<std::wstring>/16384                35329 ns        35330 ns        19796 bytes_per_second=1.72759G/s
+BM_format_to_n_string_back_inserter<std::wstring>/32768                70616 ns        70616 ns         9913 bytes_per_second=1.72865G/s
+BM_format_to_n_string_back_inserter<std::wstring>/65536               142128 ns       142124 ns         4921 bytes_per_second=1.71781G/s
+BM_format_to_n_string_back_inserter<std::wstring>/131072              284796 ns       284798 ns         2458 bytes_per_second=1.71448G/s
+BM_format_to_n_string_back_inserter<std::wstring>/262144              580646 ns       580644 ns         1194 bytes_per_second=1.68186G/s
+BM_format_to_n_string_back_inserter<std::wstring>/524288             1230857 ns      1230802 ns          565 bytes_per_second=1.58687G/s
+BM_format_to_n_string_back_inserter<std::wstring>/1048576            2677365 ns      2677206 ns          259 bytes_per_second=1.45908G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1             62.6 ns         62.6 ns     11179052 bytes_per_second=60.9279M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/2             63.4 ns         63.4 ns     11069702 bytes_per_second=120.342M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/4             67.0 ns         67.0 ns     10473053 bytes_per_second=227.888M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/8             72.2 ns         72.2 ns      9711918 bytes_per_second=422.503M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/16            84.0 ns         84.0 ns      8343813 bytes_per_second=726.632M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/32             117 ns          117 ns      5982430 bytes_per_second=1043.3M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/64             179 ns          179 ns      3915497 bytes_per_second=1.33425G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/128            317 ns          317 ns      2209097 bytes_per_second=1.50518G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/256            577 ns          577 ns      1212290 bytes_per_second=1.65202G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/512           1151 ns         1151 ns       608759 bytes_per_second=1.65652G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1024          2196 ns         2196 ns       319050 bytes_per_second=1.73723G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/2048          4320 ns         4320 ns       162683 bytes_per_second=1.76603G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/4096          8349 ns         8349 ns        83557 bytes_per_second=1.82752G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/8192         16515 ns        16515 ns        42392 bytes_per_second=1.84791G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/16384        34076 ns        34076 ns        20539 bytes_per_second=1.79116G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/32768        67903 ns        67903 ns        10308 bytes_per_second=1.79771G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/65536       136826 ns       136826 ns         5118 bytes_per_second=1.78431G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/131072      271652 ns       271651 ns         2578 bytes_per_second=1.79745G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/262144      554942 ns       554928 ns         1260 bytes_per_second=1.7598G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/524288     1185361 ns      1185335 ns          589 bytes_per_second=1.64774G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1048576    2585476 ns      2585385 ns          270 bytes_per_second=1.5109G/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1               55.3 ns         55.3 ns     12651922 bytes_per_second=69.0052M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/2               70.8 ns         70.8 ns      9907684 bytes_per_second=107.829M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/4                102 ns          102 ns      6891284 bytes_per_second=149.739M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/8                171 ns          171 ns      4091972 bytes_per_second=178.862M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/16               321 ns          321 ns      2199473 bytes_per_second=190.355M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/32               635 ns          635 ns      1102692 bytes_per_second=192.179M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/64              1224 ns         1224 ns       569797 bytes_per_second=199.44M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/128             2393 ns         2393 ns       292583 bytes_per_second=204.038M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/256             4761 ns         4761 ns       147069 bytes_per_second=205.122M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/512             9516 ns         9516 ns        73572 bytes_per_second=205.237M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1024           19068 ns        19068 ns        36720 bytes_per_second=204.858M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/2048           37957 ns        37957 ns        18438 bytes_per_second=205.827M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/4096           76192 ns        76192 ns         9188 bytes_per_second=205.073M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/8192          152768 ns       152769 ns         4579 bytes_per_second=204.557M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/16384         305345 ns       305345 ns         2293 bytes_per_second=204.687M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/32768         611084 ns       611079 ns         1140 bytes_per_second=204.556M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/65536        1223328 ns      1223324 ns          568 bytes_per_second=204.361M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/131072       2460265 ns      2460239 ns          284 bytes_per_second=203.232M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/262144       5049334 ns      5049203 ns          132 bytes_per_second=198.051M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/524288      10332440 ns     10331748 ns           63 bytes_per_second=193.578M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1048576     20957352 ns     20956612 ns           31 bytes_per_second=190.871M/s
+BM_format_to_n_string_begin<std::wstring>/1                             39.2 ns         39.2 ns     17879339 bytes_per_second=97.3141M/s
+BM_format_to_n_string_begin<std::wstring>/2                             41.1 ns         41.1 ns     17041536 bytes_per_second=185.649M/s
+BM_format_to_n_string_begin<std::wstring>/4                             43.7 ns         43.7 ns     16042309 bytes_per_second=349.542M/s
+BM_format_to_n_string_begin<std::wstring>/8                             58.9 ns         58.9 ns     12250179 bytes_per_second=517.901M/s
+BM_format_to_n_string_begin<std::wstring>/16                            67.2 ns         67.2 ns     10412676 bytes_per_second=907.659M/s
+BM_format_to_n_string_begin<std::wstring>/32                            89.1 ns         89.1 ns      7839512 bytes_per_second=1.33809G/s
+BM_format_to_n_string_begin<std::wstring>/64                             151 ns          151 ns      4652677 bytes_per_second=1.58387G/s
+BM_format_to_n_string_begin<std::wstring>/128                            254 ns          254 ns      2753719 bytes_per_second=1.87589G/s
+BM_format_to_n_string_begin<std::wstring>/256                            463 ns          463 ns      1510495 bytes_per_second=2.0578G/s
+BM_format_to_n_string_begin<std::wstring>/512                            883 ns          883 ns       793668 bytes_per_second=2.16121G/s
+BM_format_to_n_string_begin<std::wstring>/1024                          1703 ns         1703 ns       410917 bytes_per_second=2.24023G/s
+BM_format_to_n_string_begin<std::wstring>/2048                          3264 ns         3264 ns       214383 bytes_per_second=2.33733G/s
+BM_format_to_n_string_begin<std::wstring>/4096                          7320 ns         7320 ns        95623 bytes_per_second=2.08453G/s
+BM_format_to_n_string_begin<std::wstring>/8192                         14558 ns        14558 ns        48082 bytes_per_second=2.09627G/s
+BM_format_to_n_string_begin<std::wstring>/16384                        29280 ns        29280 ns        23915 bytes_per_second=2.08456G/s
+BM_format_to_n_string_begin<std::wstring>/32768                        60973 ns        60972 ns        11487 bytes_per_second=2.00207G/s
+BM_format_to_n_string_begin<std::wstring>/65536                       121475 ns       121476 ns         5751 bytes_per_second=2.00979G/s
+BM_format_to_n_string_begin<std::wstring>/131072                      243676 ns       243676 ns         2875 bytes_per_second=2.00382G/s
+BM_format_to_n_string_begin<std::wstring>/262144                      488180 ns       488181 ns         1433 bytes_per_second=2.00041G/s
+BM_format_to_n_string_begin<std::wstring>/524288                      996113 ns       996076 ns          703 bytes_per_second=1.96082G/s
+BM_format_to_n_string_begin<std::wstring>/1048576                    2134772 ns      2134665 ns          328 bytes_per_second=1.82991G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1                     39.1 ns         39.1 ns     17931576 bytes_per_second=97.6593M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/2                     40.8 ns         40.8 ns     17149621 bytes_per_second=186.975M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/4                     43.6 ns         43.6 ns     16080705 bytes_per_second=350.288M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/8                     56.4 ns         56.4 ns     12088317 bytes_per_second=541.257M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/16                    66.3 ns         66.3 ns     10571245 bytes_per_second=920.672M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/32                    87.4 ns         87.4 ns      8101473 bytes_per_second=1.36346G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/64                     151 ns          151 ns      4649051 bytes_per_second=1.58291G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/128                    254 ns          254 ns      2754766 bytes_per_second=1.87618G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/256                    463 ns          463 ns      1509421 bytes_per_second=2.05827G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/512                    884 ns          884 ns       789340 bytes_per_second=2.15795G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1024                  1704 ns         1704 ns       410693 bytes_per_second=2.23869G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/2048                  3262 ns         3262 ns       214464 bytes_per_second=2.33858G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/4096                  7326 ns         7326 ns        95559 bytes_per_second=2.08271G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/8192                 14555 ns        14555 ns        48095 bytes_per_second=2.09674G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/16384                29272 ns        29272 ns        23916 bytes_per_second=2.08512G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/32768                60976 ns        60975 ns        11458 bytes_per_second=2.00196G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/65536               121478 ns       121476 ns         5766 bytes_per_second=2.00979G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/131072              243490 ns       243490 ns         2875 bytes_per_second=2.00535G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/262144              488261 ns       488260 ns         1434 bytes_per_second=2.00009G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/524288              996621 ns       996590 ns          703 bytes_per_second=1.95981G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1048576            2134216 ns      2134176 ns          328 bytes_per_second=1.83033G/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1                       38.4 ns         38.4 ns     18243097 bytes_per_second=99.3254M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/2                       41.1 ns         41.1 ns     17009266 bytes_per_second=185.419M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/4                       48.0 ns         48.0 ns     14589459 bytes_per_second=317.648M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/8                       64.9 ns         64.9 ns     10787373 bytes_per_second=470.416M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/16                      95.6 ns         95.6 ns      7327124 bytes_per_second=638.583M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/32                       166 ns          166 ns      4204772 bytes_per_second=733.258M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/64                       306 ns          306 ns      2285012 bytes_per_second=798.685M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/128                      580 ns          580 ns      1207037 bytes_per_second=841.779M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/256                     1138 ns         1138 ns       615218 bytes_per_second=858.325M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/512                     2222 ns         2222 ns       312946 bytes_per_second=878.822M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1024                    4448 ns         4448 ns       157313 bytes_per_second=878.224M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/2048                    8785 ns         8785 ns        79654 bytes_per_second=889.332M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/4096                   17558 ns        17558 ns        39813 bytes_per_second=889.912M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/8192                   34938 ns        34938 ns        20038 bytes_per_second=894.43M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/16384                  69797 ns        69798 ns        10025 bytes_per_second=895.444M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/32768                 139086 ns       139084 ns         5034 bytes_per_second=898.74M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/65536                 278179 ns       278179 ns         2518 bytes_per_second=898.703M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/131072                570410 ns       570402 ns         1229 bytes_per_second=876.575M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/262144               1267253 ns      1267176 ns          553 bytes_per_second=789.156M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/524288               2678608 ns      2676752 ns          261 bytes_per_second=747.174M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1048576              5430153 ns      5429907 ns          129 bytes_per_second=736.661M/s
+BM_format_to_n_string_span<wchar_t>/1                                   39.1 ns         39.1 ns     17899627 bytes_per_second=97.5535M/s
+BM_format_to_n_string_span<wchar_t>/2                                   40.9 ns         40.9 ns     17128988 bytes_per_second=186.725M/s
+BM_format_to_n_string_span<wchar_t>/4                                   43.0 ns         43.0 ns     16272362 bytes_per_second=354.635M/s
+BM_format_to_n_string_span<wchar_t>/8                                   52.3 ns         52.3 ns     13408073 bytes_per_second=583.639M/s
+BM_format_to_n_string_span<wchar_t>/16                                  64.5 ns         64.5 ns     10495015 bytes_per_second=946.856M/s
+BM_format_to_n_string_span<wchar_t>/32                                  87.8 ns         87.8 ns      7860044 bytes_per_second=1.35717G/s
+BM_format_to_n_string_span<wchar_t>/64                                   150 ns          150 ns      4667100 bytes_per_second=1.58553G/s
+BM_format_to_n_string_span<wchar_t>/128                                  254 ns          254 ns      2753794 bytes_per_second=1.87544G/s
+BM_format_to_n_string_span<wchar_t>/256                                  463 ns          463 ns      1511166 bytes_per_second=2.05882G/s
+BM_format_to_n_string_span<wchar_t>/512                                  884 ns          884 ns       791508 bytes_per_second=2.157G/s
+BM_format_to_n_string_span<wchar_t>/1024                                1706 ns         1706 ns       410235 bytes_per_second=2.23586G/s
+BM_format_to_n_string_span<wchar_t>/2048                                3264 ns         3264 ns       214458 bytes_per_second=2.33712G/s
+BM_format_to_n_string_span<wchar_t>/4096                                7327 ns         7327 ns        95615 bytes_per_second=2.08253G/s
+BM_format_to_n_string_span<wchar_t>/8192                               14552 ns        14552 ns        48105 bytes_per_second=2.09713G/s
+BM_format_to_n_string_span<wchar_t>/16384                              29288 ns        29288 ns        23905 bytes_per_second=2.08397G/s
+BM_format_to_n_string_span<wchar_t>/32768                              61005 ns        61006 ns        11482 bytes_per_second=2.00097G/s
+BM_format_to_n_string_span<wchar_t>/65536                             121661 ns       121658 ns         5753 bytes_per_second=2.00678G/s
+BM_format_to_n_string_span<wchar_t>/131072                            243695 ns       243696 ns         2868 bytes_per_second=2.00365G/s
+BM_format_to_n_string_span<wchar_t>/262144                            488393 ns       488393 ns         1433 bytes_per_second=1.99954G/s
+BM_format_to_n_string_span<wchar_t>/524288                            997654 ns       997622 ns          701 bytes_per_second=1.95778G/s
+BM_format_to_n_string_span<wchar_t>/1048576                          2134304 ns      2134177 ns          328 bytes_per_second=1.83033G/s
+BM_format_to_n_string_pointer<wchar_t>/1                                39.0 ns         39.0 ns     17966665 bytes_per_second=97.8969M/s
+BM_format_to_n_string_pointer<wchar_t>/2                                40.8 ns         40.8 ns     17157092 bytes_per_second=186.93M/s
+BM_format_to_n_string_pointer<wchar_t>/4                                43.3 ns         43.3 ns     16166107 bytes_per_second=352.34M/s
+BM_format_to_n_string_pointer<wchar_t>/8                                53.4 ns         53.4 ns     13073661 bytes_per_second=571.621M/s
+BM_format_to_n_string_pointer<wchar_t>/16                               65.3 ns         65.3 ns     10434709 bytes_per_second=934.368M/s
+BM_format_to_n_string_pointer<wchar_t>/32                               87.7 ns         87.7 ns      8002398 bytes_per_second=1.35964G/s
+BM_format_to_n_string_pointer<wchar_t>/64                                149 ns          149 ns      4695115 bytes_per_second=1.59786G/s
+BM_format_to_n_string_pointer<wchar_t>/128                               251 ns          251 ns      2792277 bytes_per_second=1.89978G/s
+BM_format_to_n_string_pointer<wchar_t>/256                               452 ns          452 ns      1550249 bytes_per_second=2.11155G/s
+BM_format_to_n_string_pointer<wchar_t>/512                               873 ns          873 ns       800872 bytes_per_second=2.18362G/s
+BM_format_to_n_string_pointer<wchar_t>/1024                             1696 ns         1696 ns       412577 bytes_per_second=2.24965G/s
+BM_format_to_n_string_pointer<wchar_t>/2048                             3264 ns         3264 ns       214487 bytes_per_second=2.33775G/s
+BM_format_to_n_string_pointer<wchar_t>/4096                             7339 ns         7339 ns        95428 bytes_per_second=2.07905G/s
+BM_format_to_n_string_pointer<wchar_t>/8192                            14602 ns        14602 ns        47964 bytes_per_second=2.08992G/s
+BM_format_to_n_string_pointer<wchar_t>/16384                           29362 ns        29363 ns        23839 bytes_per_second=2.07868G/s
+BM_format_to_n_string_pointer<wchar_t>/32768                           61190 ns        61190 ns        11440 bytes_per_second=1.99493G/s
+BM_format_to_n_string_pointer<wchar_t>/65536                          122093 ns       122093 ns         5721 bytes_per_second=1.99964G/s
+BM_format_to_n_string_pointer<wchar_t>/131072                         244452 ns       244453 ns         2864 bytes_per_second=1.99745G/s
+BM_format_to_n_string_pointer<wchar_t>/262144                         489964 ns       489967 ns         1429 bytes_per_second=1.99312G/s
+BM_format_to_n_string_pointer<wchar_t>/524288                        1004479 ns      1004467 ns          697 bytes_per_second=1.94444G/s
+BM_format_to_n_string_pointer<wchar_t>/1048576                       2147876 ns      2147791 ns          325 bytes_per_second=1.81873G/s

libcxx/after-v2/formatted_size.txt

+----------------------------------------------------------------------------------------------------
+Benchmark                                          Time             CPU   Iterations UserCounters...
+----------------------------------------------------------------------------------------------------
+BM_formatted_size_string<char>/1                32.9 ns         32.9 ns     21299645 bytes_per_second=29.0269M/s
+BM_formatted_size_string<char>/2                17.0 ns         17.0 ns     41230756 bytes_per_second=112.292M/s
+BM_formatted_size_string<char>/4                9.42 ns         9.42 ns     74268012 bytes_per_second=404.775M/s
+BM_formatted_size_string<char>/8                5.97 ns         5.97 ns    117012288 bytes_per_second=1.24792G/s
+BM_formatted_size_string<char>/16               3.65 ns         3.65 ns    193623648 bytes_per_second=4.0794G/s
+BM_formatted_size_string<char>/32               2.78 ns         2.78 ns    251200768 bytes_per_second=10.7207G/s
+BM_formatted_size_string<char>/64               2.34 ns         2.34 ns    299106624 bytes_per_second=25.5077G/s
+BM_formatted_size_string<char>/128              2.04 ns         2.04 ns    343667712 bytes_per_second=58.5637G/s
+BM_formatted_size_string<char>/256              2.01 ns         2.01 ns    347318528 bytes_per_second=118.508G/s
+BM_formatted_size_string<char>/512              1.90 ns         1.90 ns    367739392 bytes_per_second=250.917G/s
+BM_formatted_size_string<char>/1024             1.87 ns         1.87 ns    374341632 bytes_per_second=510.908G/s
+BM_formatted_size_string<char>/2048             1.87 ns         1.87 ns    373684224 bytes_per_second=1018.38G/s
+BM_formatted_size_string<char>/4096             1.87 ns         1.87 ns    374644736 bytes_per_second=1.99733T/s
+BM_formatted_size_string<char>/8192             1.87 ns         1.87 ns    375414784 bytes_per_second=3.99068T/s
+BM_formatted_size_string<char>/16384            1.87 ns         1.87 ns    374669312 bytes_per_second=7.97138T/s
+BM_formatted_size_string<char>/32768            1.87 ns         1.87 ns    374308864 bytes_per_second=15.9274T/s
+BM_formatted_size_string<char>/65536            1.87 ns         1.87 ns    374145024 bytes_per_second=31.8561T/s
+BM_formatted_size_string<char>/131072           1.87 ns         1.87 ns    374341632 bytes_per_second=63.7177T/s
+BM_formatted_size_string<char>/262144           1.87 ns         1.87 ns    374341632 bytes_per_second=127.497T/s
+BM_formatted_size_string<char>/524288           1.87 ns         1.87 ns    374341632 bytes_per_second=254.812T/s
+BM_formatted_size_string<char>/1048576          1.87 ns         1.87 ns    374341632 bytes_per_second=509.957T/s
+BM_formatted_size_string<wchar_t>/1             32.6 ns         32.6 ns     21477612 bytes_per_second=117.09M/s
+BM_formatted_size_string<wchar_t>/2             16.7 ns         16.7 ns     41948414 bytes_per_second=457.108M/s
+BM_formatted_size_string<wchar_t>/4             8.76 ns         8.76 ns     79932524 bytes_per_second=1.70066G/s
+BM_formatted_size_string<wchar_t>/8             4.70 ns         4.70 ns    148856240 bytes_per_second=6.33691G/s
+BM_formatted_size_string<wchar_t>/16            2.70 ns         2.70 ns    259338992 bytes_per_second=22.0842G/s
+BM_formatted_size_string<wchar_t>/32            1.70 ns         1.70 ns    411589600 bytes_per_second=70.0658G/s
+BM_formatted_size_string<wchar_t>/64            1.35 ns         1.35 ns    516741888 bytes_per_second=176.504G/s
+BM_formatted_size_string<wchar_t>/128           1.14 ns         1.14 ns    615456512 bytes_per_second=418.985G/s
+BM_formatted_size_string<wchar_t>/256           1.03 ns         1.03 ns    682187520 bytes_per_second=929.724G/s
+BM_formatted_size_string<wchar_t>/512          0.959 ns        0.959 ns    729412096 bytes_per_second=1.94251T/s
+BM_formatted_size_string<wchar_t>/1024         0.905 ns        0.905 ns    773460992 bytes_per_second=4.11624T/s
+BM_formatted_size_string<wchar_t>/2048         0.879 ns        0.879 ns    796520448 bytes_per_second=8.47808T/s
+BM_formatted_size_string<wchar_t>/4096         0.866 ns        0.866 ns    807378944 bytes_per_second=17.2158T/s
+BM_formatted_size_string<wchar_t>/8192         0.859 ns        0.859 ns    815185920 bytes_per_second=34.7086T/s
+BM_formatted_size_string<wchar_t>/16384        0.857 ns        0.857 ns    816742400 bytes_per_second=69.5887T/s
+BM_formatted_size_string<wchar_t>/32768        0.855 ns        0.855 ns    819757056 bytes_per_second=139.459T/s
+BM_formatted_size_string<wchar_t>/65536        0.852 ns        0.852 ns    820314112 bytes_per_second=279.849T/s
+BM_formatted_size_string<wchar_t>/131072       0.850 ns        0.850 ns    823525376 bytes_per_second=560.798T/s
+BM_formatted_size_string<wchar_t>/262144       0.850 ns        0.850 ns    823656448 bytes_per_second=1121.77T/s
+BM_formatted_size_string<wchar_t>/524288       0.850 ns        0.850 ns    824180736 bytes_per_second=2.19239P/s
+BM_formatted_size_string<wchar_t>/1048576      0.851 ns        0.851 ns    823132160 bytes_per_second=4.37789P/s

libcxx/after/format.txt

+--------------------------------------------------------------------------------------------
+Benchmark                                  Time             CPU   Iterations UserCounters...
+--------------------------------------------------------------------------------------------
+BM_format_string<char>/1                39.9 ns         39.9 ns     17552546 bytes_per_second=23.8978M/s
+BM_format_string<char>/2                20.6 ns         20.6 ns     33916716 bytes_per_second=92.3976M/s
+BM_format_string<char>/4                10.9 ns         10.9 ns     64314816 bytes_per_second=350.237M/s
+BM_format_string<char>/8                6.26 ns         6.26 ns    111850632 bytes_per_second=1.18951G/s
+BM_format_string<char>/16               4.02 ns         4.02 ns    177472176 bytes_per_second=3.71019G/s
+BM_format_string<char>/32               3.42 ns         3.42 ns    204388576 bytes_per_second=8.71004G/s
+BM_format_string<char>/64               2.62 ns         2.62 ns    267209408 bytes_per_second=22.7567G/s
+BM_format_string<char>/128              2.21 ns         2.21 ns    316880512 bytes_per_second=54.0118G/s
+BM_format_string<char>/256              2.08 ns         2.08 ns    335966976 bytes_per_second=114.89G/s
+BM_format_string<char>/512              2.01 ns         2.01 ns    347648512 bytes_per_second=237.072G/s
+BM_format_string<char>/1024             1.98 ns         1.98 ns    353010688 bytes_per_second=480.737G/s
+BM_format_string<char>/2048             1.97 ns         1.97 ns    355923968 bytes_per_second=970.081G/s
+BM_format_string<char>/4096             1.93 ns         1.93 ns    358481920 bytes_per_second=1.93223T/s
+BM_format_string<char>/8192             1.91 ns         1.91 ns    366919680 bytes_per_second=3.90296T/s
+BM_format_string<char>/16384            1.90 ns         1.90 ns    367886336 bytes_per_second=7.83345T/s
+BM_format_string<char>/32768            1.90 ns         1.90 ns    368738304 bytes_per_second=15.711T/s
+BM_format_string<char>/65536            1.95 ns         1.95 ns    359530496 bytes_per_second=30.5949T/s
+BM_format_string<char>/131072           2.20 ns         2.20 ns    317587456 bytes_per_second=54.173T/s
+BM_format_string<char>/262144           2.31 ns         2.31 ns    302514176 bytes_per_second=103.03T/s
+BM_format_string<char>/524288           2.37 ns         2.37 ns    295698432 bytes_per_second=201.329T/s
+BM_format_string<char>/1048576          2.41 ns         2.41 ns    290455552 bytes_per_second=395.301T/s
+BM_format_string<wchar_t>/1             38.2 ns         38.2 ns     18356772 bytes_per_second=99.9782M/s
+BM_format_string<wchar_t>/2             19.6 ns         19.6 ns     35786460 bytes_per_second=390.058M/s
+BM_format_string<wchar_t>/4             10.2 ns         10.2 ns     68367388 bytes_per_second=1.45511G/s
+BM_format_string<wchar_t>/8             8.63 ns         8.63 ns     81115856 bytes_per_second=3.45447G/s
+BM_format_string<wchar_t>/16            4.77 ns         4.77 ns    146824224 bytes_per_second=12.4957G/s
+BM_format_string<wchar_t>/32            2.62 ns         2.62 ns    266898400 bytes_per_second=45.515G/s
+BM_format_string<wchar_t>/64            1.80 ns         1.80 ns    388845312 bytes_per_second=132.474G/s
+BM_format_string<wchar_t>/128           1.52 ns         1.52 ns    461058816 bytes_per_second=313.566G/s
+BM_format_string<wchar_t>/256           1.39 ns         1.39 ns    504096256 bytes_per_second=687.538G/s
+BM_format_string<wchar_t>/512           1.32 ns         1.32 ns    531521024 bytes_per_second=1.41323T/s
+BM_format_string<wchar_t>/1024          1.17 ns         1.17 ns    598879232 bytes_per_second=3.19636T/s
+BM_format_string<wchar_t>/2048          1.09 ns         1.09 ns    635691008 bytes_per_second=6.85522T/s
+BM_format_string<wchar_t>/4096          1.07 ns         1.07 ns    654000128 bytes_per_second=13.9686T/s
+BM_format_string<wchar_t>/8192          1.07 ns         1.07 ns    655245312 bytes_per_second=27.8821T/s
+BM_format_string<wchar_t>/16384         1.07 ns         1.07 ns    655556608 bytes_per_second=55.8097T/s
+BM_format_string<wchar_t>/32768         1.16 ns         1.16 ns    605552640 bytes_per_second=103.077T/s
+BM_format_string<wchar_t>/65536         1.16 ns         1.16 ns    604831744 bytes_per_second=206.065T/s
+BM_format_string<wchar_t>/131072        1.18 ns         1.18 ns    593231872 bytes_per_second=404.64T/s
+BM_format_string<wchar_t>/262144        3.11 ns         3.11 ns    225181696 bytes_per_second=306.269T/s
+BM_format_string<wchar_t>/524288        3.31 ns         3.31 ns    210763776 bytes_per_second=577.021T/s
+BM_format_string<wchar_t>/1048576       3.14 ns         3.14 ns    223346688 bytes_per_second=1.18499P/s

libcxx/after/format_to.txt

+--------------------------------------------------------------------------------------------------------------------------
+Benchmark                                                                Time             CPU   Iterations UserCounters...
+--------------------------------------------------------------------------------------------------------------------------
+BM_format_to_string_back_inserter<std::string>/1                      38.3 ns         38.3 ns     18297734 bytes_per_second=24.9221M/s
+BM_format_to_string_back_inserter<std::string>/2                      39.6 ns         39.6 ns     17702017 bytes_per_second=48.2203M/s
+BM_format_to_string_back_inserter<std::string>/4                      43.3 ns         43.3 ns     16148184 bytes_per_second=88.0623M/s
+BM_format_to_string_back_inserter<std::string>/8                      51.5 ns         51.5 ns     13478135 bytes_per_second=148.037M/s
+BM_format_to_string_back_inserter<std::string>/16                     63.6 ns         63.6 ns     11014778 bytes_per_second=239.781M/s
+BM_format_to_string_back_inserter<std::string>/32                      111 ns          111 ns      6324490 bytes_per_second=275.84M/s
+BM_format_to_string_back_inserter<std::string>/64                      169 ns          169 ns      4136649 bytes_per_second=361.225M/s
+BM_format_to_string_back_inserter<std::string>/128                     281 ns          281 ns      2488654 bytes_per_second=433.911M/s
+BM_format_to_string_back_inserter<std::string>/256                     531 ns          531 ns      1318006 bytes_per_second=459.794M/s
+BM_format_to_string_back_inserter<std::string>/512                    1031 ns         1031 ns       678675 bytes_per_second=473.402M/s
+BM_format_to_string_back_inserter<std::string>/1024                   2071 ns         2071 ns       338055 bytes_per_second=471.489M/s
+BM_format_to_string_back_inserter<std::string>/2048                   4069 ns         4070 ns       172076 bytes_per_second=479.94M/s
+BM_format_to_string_back_inserter<std::string>/4096                   8011 ns         8011 ns        87261 bytes_per_second=487.591M/s
+BM_format_to_string_back_inserter<std::string>/8192                  15811 ns        15811 ns        44282 bytes_per_second=494.117M/s
+BM_format_to_string_back_inserter<std::string>/16384                 31318 ns        31318 ns        22343 bytes_per_second=498.92M/s
+BM_format_to_string_back_inserter<std::string>/32768                 62396 ns        62396 ns        11231 bytes_per_second=500.831M/s
+BM_format_to_string_back_inserter<std::string>/65536                124432 ns       124433 ns         5624 bytes_per_second=502.279M/s
+BM_format_to_string_back_inserter<std::string>/131072               273737 ns       273738 ns         2559 bytes_per_second=456.64M/s
+BM_format_to_string_back_inserter<std::string>/262144               590603 ns       590608 ns         1186 bytes_per_second=423.293M/s
+BM_format_to_string_back_inserter<std::string>/524288              1227943 ns      1227924 ns          569 bytes_per_second=407.191M/s
+BM_format_to_string_back_inserter<std::string>/1048576             2511763 ns      2511778 ns          278 bytes_per_second=398.124M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1                55.6 ns         55.6 ns     12565404 bytes_per_second=17.1377M/s
+BM_format_to_string_back_inserter<std::vector<char>>/2                56.8 ns         56.8 ns     12337051 bytes_per_second=33.5987M/s
+BM_format_to_string_back_inserter<std::vector<char>>/4                58.1 ns         58.1 ns     12046940 bytes_per_second=65.6904M/s
+BM_format_to_string_back_inserter<std::vector<char>>/8                61.7 ns         61.7 ns     11368464 bytes_per_second=123.715M/s
+BM_format_to_string_back_inserter<std::vector<char>>/16               77.5 ns         77.5 ns      9031992 bytes_per_second=196.825M/s
+BM_format_to_string_back_inserter<std::vector<char>>/32                106 ns          106 ns      6645752 bytes_per_second=289.254M/s
+BM_format_to_string_back_inserter<std::vector<char>>/64                162 ns          162 ns      4313169 bytes_per_second=375.926M/s
+BM_format_to_string_back_inserter<std::vector<char>>/128               277 ns          277 ns      2526260 bytes_per_second=440.374M/s
+BM_format_to_string_back_inserter<std::vector<char>>/256               524 ns          524 ns      1334850 bytes_per_second=465.705M/s
+BM_format_to_string_back_inserter<std::vector<char>>/512              1021 ns         1021 ns       685068 bytes_per_second=478.155M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1024             1986 ns         1986 ns       352390 bytes_per_second=491.777M/s
+BM_format_to_string_back_inserter<std::vector<char>>/2048             3975 ns         3975 ns       176085 bytes_per_second=491.306M/s
+BM_format_to_string_back_inserter<std::vector<char>>/4096             7869 ns         7869 ns        88385 bytes_per_second=496.426M/s
+BM_format_to_string_back_inserter<std::vector<char>>/8192            15585 ns        15585 ns        44930 bytes_per_second=501.273M/s
+BM_format_to_string_back_inserter<std::vector<char>>/16384           30986 ns        30984 ns        22590 bytes_per_second=504.287M/s
+BM_format_to_string_back_inserter<std::vector<char>>/32768           62200 ns        62199 ns        11272 bytes_per_second=502.417M/s
+BM_format_to_string_back_inserter<std::vector<char>>/65536          123241 ns       123241 ns         5677 bytes_per_second=507.136M/s
+BM_format_to_string_back_inserter<std::vector<char>>/131072         247874 ns       247875 ns         2822 bytes_per_second=504.287M/s
+BM_format_to_string_back_inserter<std::vector<char>>/262144         497793 ns       497798 ns         1408 bytes_per_second=502.212M/s
+BM_format_to_string_back_inserter<std::vector<char>>/524288         993798 ns       993798 ns          704 bytes_per_second=503.12M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1048576       1992287 ns      1992284 ns          351 bytes_per_second=501.936M/s
+BM_format_to_string_back_inserter<std::list<char>>/1                  50.3 ns         50.3 ns     13915126 bytes_per_second=18.9504M/s
+BM_format_to_string_back_inserter<std::list<char>>/2                  65.8 ns         65.8 ns     10572505 bytes_per_second=28.9952M/s
+BM_format_to_string_back_inserter<std::list<char>>/4                  93.5 ns         93.5 ns      7465609 bytes_per_second=40.7777M/s
+BM_format_to_string_back_inserter<std::list<char>>/8                   158 ns          158 ns      4429982 bytes_per_second=48.2692M/s
+BM_format_to_string_back_inserter<std::list<char>>/16                  303 ns          303 ns      2309806 bytes_per_second=50.3301M/s
+BM_format_to_string_back_inserter<std::list<char>>/32                  612 ns          612 ns      1139033 bytes_per_second=49.8926M/s
+BM_format_to_string_back_inserter<std::list<char>>/64                 1199 ns         1199 ns       583328 bytes_per_second=50.8887M/s
+BM_format_to_string_back_inserter<std::list<char>>/128                2357 ns         2357 ns       296934 bytes_per_second=51.78M/s
+BM_format_to_string_back_inserter<std::list<char>>/256                4708 ns         4708 ns       148658 bytes_per_second=51.855M/s
+BM_format_to_string_back_inserter<std::list<char>>/512                9395 ns         9395 ns        74320 bytes_per_second=51.9706M/s
+BM_format_to_string_back_inserter<std::list<char>>/1024              18924 ns        18924 ns        36981 bytes_per_second=51.6046M/s
+BM_format_to_string_back_inserter<std::list<char>>/2048              37908 ns        37909 ns        18438 bytes_per_second=51.5219M/s
+BM_format_to_string_back_inserter<std::list<char>>/4096              75932 ns        75932 ns         9210 bytes_per_second=51.4441M/s
+BM_format_to_string_back_inserter<std::list<char>>/8192             152343 ns       152342 ns         4591 bytes_per_second=51.2825M/s
+BM_format_to_string_back_inserter<std::list<char>>/16384            305396 ns       305398 ns         2289 bytes_per_second=51.1628M/s
+BM_format_to_string_back_inserter<std::list<char>>/32768            612232 ns       612233 ns         1135 bytes_per_second=51.0427M/s
+BM_format_to_string_back_inserter<std::list<char>>/65536           1225854 ns      1225862 ns          568 bytes_per_second=50.9845M/s
+BM_format_to_string_back_inserter<std::list<char>>/131072          2472250 ns      2472143 ns          282 bytes_per_second=50.5634M/s
+BM_format_to_string_back_inserter<std::list<char>>/262144          5160752 ns      5160599 ns          125 bytes_per_second=48.444M/s
+BM_format_to_string_back_inserter<std::list<char>>/524288         10549493 ns     10549294 ns           62 bytes_per_second=47.3965M/s
+BM_format_to_string_back_inserter<std::list<char>>/1048576        21394567 ns     21394175 ns           31 bytes_per_second=46.7417M/s
+BM_format_to_string_begin<std::string>/1                              34.6 ns         34.6 ns     20197584 bytes_per_second=27.546M/s
+BM_format_to_string_begin<std::string>/2                              35.5 ns         35.5 ns     19738899 bytes_per_second=53.7223M/s
+BM_format_to_string_begin<std::string>/4                              38.5 ns         38.5 ns     18167622 bytes_per_second=98.9559M/s
+BM_format_to_string_begin<std::string>/8                              46.2 ns         46.2 ns     15029843 bytes_per_second=165.086M/s
+BM_format_to_string_begin<std::string>/16                             61.0 ns         61.0 ns     11479442 bytes_per_second=250.141M/s
+BM_format_to_string_begin<std::string>/32                             88.0 ns         88.0 ns      7959176 bytes_per_second=346.796M/s
+BM_format_to_string_begin<std::string>/64                              144 ns          144 ns      4839003 bytes_per_second=422.983M/s
+BM_format_to_string_begin<std::string>/128                             261 ns          261 ns      2683079 bytes_per_second=467.708M/s
+BM_format_to_string_begin<std::string>/256                             501 ns          501 ns      1396906 bytes_per_second=486.934M/s
+BM_format_to_string_begin<std::string>/512                             969 ns          969 ns       723024 bytes_per_second=503.936M/s
+BM_format_to_string_begin<std::string>/1024                           1908 ns         1908 ns       366716 bytes_per_second=511.772M/s
+BM_format_to_string_begin<std::string>/2048                           3783 ns         3783 ns       185073 bytes_per_second=516.314M/s
+BM_format_to_string_begin<std::string>/4096                           7525 ns         7525 ns        93043 bytes_per_second=519.092M/s
+BM_format_to_string_begin<std::string>/8192                          15018 ns        15018 ns        46579 bytes_per_second=520.216M/s
+BM_format_to_string_begin<std::string>/16384                         29981 ns        29981 ns        23355 bytes_per_second=521.156M/s
+BM_format_to_string_begin<std::string>/32768                         59922 ns        59923 ns        11687 bytes_per_second=521.502M/s
+BM_format_to_string_begin<std::string>/65536                        119961 ns       119961 ns         5840 bytes_per_second=521.001M/s
+BM_format_to_string_begin<std::string>/131072                       240278 ns       240279 ns         2914 bytes_per_second=520.229M/s
+BM_format_to_string_begin<std::string>/262144                       480418 ns       480418 ns         1457 bytes_per_second=520.38M/s
+BM_format_to_string_begin<std::string>/524288                       960612 ns       960618 ns          729 bytes_per_second=520.498M/s
+BM_format_to_string_begin<std::string>/1048576                     1920655 ns      1920668 ns          364 bytes_per_second=520.652M/s
+BM_format_to_string_begin<std::vector<char>>/1                        34.1 ns         34.1 ns     20528420 bytes_per_second=27.9482M/s
+BM_format_to_string_begin<std::vector<char>>/2                        35.3 ns         35.3 ns     19860807 bytes_per_second=54.0447M/s
+BM_format_to_string_begin<std::vector<char>>/4                        37.8 ns         37.8 ns     18518690 bytes_per_second=101.023M/s
+BM_format_to_string_begin<std::vector<char>>/8                        44.5 ns         44.5 ns     15755985 bytes_per_second=171.617M/s
+BM_format_to_string_begin<std::vector<char>>/16                       59.1 ns         59.1 ns     11870759 bytes_per_second=258.369M/s
+BM_format_to_string_begin<std::vector<char>>/32                       88.2 ns         88.2 ns      7934480 bytes_per_second=345.817M/s
+BM_format_to_string_begin<std::vector<char>>/64                        144 ns          144 ns      4837068 bytes_per_second=422.501M/s
+BM_format_to_string_begin<std::vector<char>>/128                       259 ns          259 ns      2702904 bytes_per_second=470.902M/s
+BM_format_to_string_begin<std::vector<char>>/256                       501 ns          501 ns      1398428 bytes_per_second=487.699M/s
+BM_format_to_string_begin<std::vector<char>>/512                       973 ns          973 ns       718651 bytes_per_second=501.745M/s
+BM_format_to_string_begin<std::vector<char>>/1024                     1908 ns         1908 ns       367022 bytes_per_second=511.732M/s
+BM_format_to_string_begin<std::vector<char>>/2048                     3784 ns         3784 ns       184867 bytes_per_second=516.212M/s
+BM_format_to_string_begin<std::vector<char>>/4096                     7521 ns         7521 ns        93032 bytes_per_second=519.346M/s
+BM_format_to_string_begin<std::vector<char>>/8192                    15022 ns        15022 ns        46623 bytes_per_second=520.073M/s
+BM_format_to_string_begin<std::vector<char>>/16384                   30003 ns        30004 ns        23356 bytes_per_second=520.769M/s
+BM_format_to_string_begin<std::vector<char>>/32768                   59954 ns        59955 ns        11653 bytes_per_second=521.223M/s
+BM_format_to_string_begin<std::vector<char>>/65536                  119858 ns       119859 ns         5839 bytes_per_second=521.446M/s
+BM_format_to_string_begin<std::vector<char>>/131072                 240172 ns       240174 ns         2916 bytes_per_second=520.455M/s
+BM_format_to_string_begin<std::vector<char>>/262144                 480655 ns       480656 ns         1457 bytes_per_second=520.123M/s
+BM_format_to_string_begin<std::vector<char>>/524288                 961120 ns       961129 ns          729 bytes_per_second=520.222M/s
+BM_format_to_string_begin<std::vector<char>>/1048576               1921407 ns      1921424 ns          364 bytes_per_second=520.447M/s
+BM_format_to_string_begin<std::list<char>>/1                          33.0 ns         33.0 ns     21213436 bytes_per_second=28.8988M/s
+BM_format_to_string_begin<std::list<char>>/2                          36.9 ns         36.9 ns     18993880 bytes_per_second=51.7446M/s
+BM_format_to_string_begin<std::list<char>>/4                          43.6 ns         43.6 ns     16067781 bytes_per_second=87.4242M/s
+BM_format_to_string_begin<std::list<char>>/8                          57.2 ns         57.2 ns     12195567 bytes_per_second=133.393M/s
+BM_format_to_string_begin<std::list<char>>/16                         92.0 ns         92.0 ns      7618123 bytes_per_second=165.897M/s
+BM_format_to_string_begin<std::list<char>>/32                          158 ns          158 ns      4437366 bytes_per_second=193.543M/s
+BM_format_to_string_begin<std::list<char>>/64                          309 ns          309 ns      2265496 bytes_per_second=197.631M/s
+BM_format_to_string_begin<std::list<char>>/128                         594 ns          594 ns      1179077 bytes_per_second=205.655M/s
+BM_format_to_string_begin<std::list<char>>/256                        1168 ns         1168 ns       599147 bytes_per_second=208.987M/s
+BM_format_to_string_begin<std::list<char>>/512                        2301 ns         2301 ns       305086 bytes_per_second=212.183M/s
+BM_format_to_string_begin<std::list<char>>/1024                       4632 ns         4632 ns       151347 bytes_per_second=210.827M/s
+BM_format_to_string_begin<std::list<char>>/2048                       9090 ns         9090 ns        76823 bytes_per_second=214.865M/s
+BM_format_to_string_begin<std::list<char>>/4096                      18109 ns        18109 ns        38640 bytes_per_second=215.703M/s
+BM_format_to_string_begin<std::list<char>>/8192                      36229 ns        36229 ns        19320 bytes_per_second=215.639M/s
+BM_format_to_string_begin<std::list<char>>/16384                     72710 ns        72710 ns         9632 bytes_per_second=214.895M/s
+BM_format_to_string_begin<std::list<char>>/32768                    145139 ns       145137 ns         4826 bytes_per_second=215.314M/s
+BM_format_to_string_begin<std::list<char>>/65536                    290048 ns       290050 ns         2414 bytes_per_second=215.48M/s
+BM_format_to_string_begin<std::list<char>>/131072                   588021 ns       588008 ns         1191 bytes_per_second=212.582M/s
+BM_format_to_string_begin<std::list<char>>/262144                  1277229 ns      1277195 ns          549 bytes_per_second=195.741M/s
+BM_format_to_string_begin<std::list<char>>/524288                  2739051 ns      2738972 ns          255 bytes_per_second=182.55M/s
+BM_format_to_string_begin<std::list<char>>/1048576                 5542334 ns      5542224 ns          126 bytes_per_second=180.433M/s
+BM_format_to_string_span<std::span<char>>/1                           34.7 ns         34.7 ns     20178334 bytes_per_second=27.5127M/s
+BM_format_to_string_span<std::span<char>>/2                           35.8 ns         35.8 ns     19545731 bytes_per_second=53.2821M/s
+BM_format_to_string_span<std::span<char>>/4                           37.8 ns         37.8 ns     18552711 bytes_per_second=100.986M/s
+BM_format_to_string_span<std::span<char>>/8                           43.8 ns         43.8 ns     15994609 bytes_per_second=174.035M/s
+BM_format_to_string_span<std::span<char>>/16                          61.6 ns         61.6 ns     11602055 bytes_per_second=247.578M/s
+BM_format_to_string_span<std::span<char>>/32                          92.0 ns         92.0 ns      7587325 bytes_per_second=331.68M/s
+BM_format_to_string_span<std::span<char>>/64                           144 ns          144 ns      4852271 bytes_per_second=423.035M/s
+BM_format_to_string_span<std::span<char>>/128                          260 ns          260 ns      2688344 bytes_per_second=468.949M/s
+BM_format_to_string_span<std::span<char>>/256                          502 ns          502 ns      1392408 bytes_per_second=486.435M/s
+BM_format_to_string_span<std::span<char>>/512                          969 ns          969 ns       721549 bytes_per_second=503.872M/s
+BM_format_to_string_span<std::span<char>>/1024                        1916 ns         1916 ns       366264 bytes_per_second=509.804M/s
+BM_format_to_string_span<std::span<char>>/2048                        3784 ns         3784 ns       184956 bytes_per_second=516.213M/s
+BM_format_to_string_span<std::span<char>>/4096                        7525 ns         7525 ns        93046 bytes_per_second=519.117M/s
+BM_format_to_string_span<std::span<char>>/8192                       15031 ns        15031 ns        46587 bytes_per_second=519.769M/s
+BM_format_to_string_span<std::span<char>>/16384                      29995 ns        29995 ns        23339 bytes_per_second=520.913M/s
+BM_format_to_string_span<std::span<char>>/32768                      59955 ns        59955 ns        11671 bytes_per_second=521.224M/s
+BM_format_to_string_span<std::span<char>>/65536                     119880 ns       119880 ns         5839 bytes_per_second=521.356M/s
+BM_format_to_string_span<std::span<char>>/131072                    240239 ns       240242 ns         2916 bytes_per_second=520.31M/s
+BM_format_to_string_span<std::span<char>>/262144                    480355 ns       480359 ns         1457 bytes_per_second=520.444M/s
+BM_format_to_string_span<std::span<char>>/524288                    960729 ns       960735 ns          729 bytes_per_second=520.435M/s
+BM_format_to_string_span<std::span<char>>/1048576                  1921211 ns      1921219 ns          364 bytes_per_second=520.503M/s
+BM_format_to_string_pointer<char*>/1                                  34.6 ns         34.6 ns     20230438 bytes_per_second=27.5805M/s
+BM_format_to_string_pointer<char*>/2                                  35.7 ns         35.7 ns     19609755 bytes_per_second=53.473M/s
+BM_format_to_string_pointer<char*>/4                                  37.9 ns         37.9 ns     18463087 bytes_per_second=100.689M/s
+BM_format_to_string_pointer<char*>/8                                  44.8 ns         44.8 ns     15654961 bytes_per_second=170.431M/s
+BM_format_to_string_pointer<char*>/16                                 59.0 ns         59.0 ns     11867159 bytes_per_second=258.478M/s
+BM_format_to_string_pointer<char*>/32                                 88.1 ns         88.1 ns      7961220 bytes_per_second=346.458M/s
+BM_format_to_string_pointer<char*>/64                                  144 ns          144 ns      4857587 bytes_per_second=423.585M/s
+BM_format_to_string_pointer<char*>/128                                 260 ns          260 ns      2686681 bytes_per_second=468.801M/s
+BM_format_to_string_pointer<char*>/256                                 501 ns          501 ns      1397163 bytes_per_second=487.15M/s
+BM_format_to_string_pointer<char*>/512                                 968 ns          968 ns       722208 bytes_per_second=504.553M/s
+BM_format_to_string_pointer<char*>/1024                               1909 ns         1909 ns       366915 bytes_per_second=511.589M/s
+BM_format_to_string_pointer<char*>/2048                               3783 ns         3783 ns       185111 bytes_per_second=516.253M/s
+BM_format_to_string_pointer<char*>/4096                               7521 ns         7521 ns        92968 bytes_per_second=519.353M/s
+BM_format_to_string_pointer<char*>/8192                              15026 ns        15026 ns        46583 bytes_per_second=519.928M/s
+BM_format_to_string_pointer<char*>/16384                             29975 ns        29976 ns        23343 bytes_per_second=521.257M/s
+BM_format_to_string_pointer<char*>/32768                             59987 ns        59987 ns        11679 bytes_per_second=520.946M/s
+BM_format_to_string_pointer<char*>/65536                            119939 ns       119939 ns         5837 bytes_per_second=521.098M/s
+BM_format_to_string_pointer<char*>/131072                           240083 ns       240085 ns         2914 bytes_per_second=520.648M/s
+BM_format_to_string_pointer<char*>/262144                           480364 ns       480368 ns         1458 bytes_per_second=520.435M/s
+BM_format_to_string_pointer<char*>/524288                           960556 ns       960561 ns          729 bytes_per_second=520.529M/s
+BM_format_to_string_pointer<char*>/1048576                         1920520 ns      1920524 ns          365 bytes_per_second=520.691M/s
+BM_format_to_string_back_inserter<std::wstring>/1                     37.8 ns         37.8 ns     18537417 bytes_per_second=101.038M/s
+BM_format_to_string_back_inserter<std::wstring>/2                     40.0 ns         40.0 ns     17501010 bytes_per_second=190.847M/s
+BM_format_to_string_back_inserter<std::wstring>/4                     41.8 ns         41.8 ns     16739748 bytes_per_second=365.009M/s
+BM_format_to_string_back_inserter<std::wstring>/8                     69.9 ns         69.9 ns      9984053 bytes_per_second=436.58M/s
+BM_format_to_string_back_inserter<std::wstring>/16                    78.4 ns         78.4 ns      8891739 bytes_per_second=778.932M/s
+BM_format_to_string_back_inserter<std::wstring>/32                    82.5 ns         82.5 ns      8493275 bytes_per_second=1.44559G/s
+BM_format_to_string_back_inserter<std::wstring>/64                     115 ns          115 ns      6098311 bytes_per_second=2.06542G/s
+BM_format_to_string_back_inserter<std::wstring>/128                    195 ns          195 ns      3587099 bytes_per_second=2.445G/s
+BM_format_to_string_back_inserter<std::wstring>/256                    380 ns          380 ns      1844174 bytes_per_second=2.51115G/s
+BM_format_to_string_back_inserter<std::wstring>/512                    719 ns          719 ns       969884 bytes_per_second=2.65445G/s
+BM_format_to_string_back_inserter<std::wstring>/1024                  1286 ns         1286 ns       544212 bytes_per_second=2.96597G/s
+BM_format_to_string_back_inserter<std::wstring>/2048                  2349 ns         2349 ns       298174 bytes_per_second=3.24784G/s
+BM_format_to_string_back_inserter<std::wstring>/4096                  4592 ns         4592 ns       152163 bytes_per_second=3.3229G/s
+BM_format_to_string_back_inserter<std::wstring>/8192                  9003 ns         9003 ns        77723 bytes_per_second=3.38972G/s
+BM_format_to_string_back_inserter<std::wstring>/16384                17924 ns        17924 ns        39067 bytes_per_second=3.40521G/s
+BM_format_to_string_back_inserter<std::wstring>/32768                37917 ns        37917 ns        18471 bytes_per_second=3.21945G/s
+BM_format_to_string_back_inserter<std::wstring>/65536                78954 ns        78954 ns         8873 bytes_per_second=3.09218G/s
+BM_format_to_string_back_inserter<std::wstring>/131072              156950 ns       156950 ns         4462 bytes_per_second=3.11106G/s
+BM_format_to_string_back_inserter<std::wstring>/262144              802909 ns       802872 ns          871 bytes_per_second=1.21634G/s
+BM_format_to_string_back_inserter<std::wstring>/524288             1725324 ns      1725150 ns          406 bytes_per_second=1.13215G/s
+BM_format_to_string_back_inserter<std::wstring>/1048576            3253046 ns      3252960 ns          215 bytes_per_second=1.20083G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1             55.1 ns         55.1 ns     12689397 bytes_per_second=69.205M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/2             55.9 ns         55.9 ns     12488871 bytes_per_second=136.466M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/4             57.9 ns         57.9 ns     12070709 bytes_per_second=263.492M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/8             60.1 ns         60.1 ns     11651746 bytes_per_second=507.803M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/16            64.6 ns         64.6 ns     10810646 bytes_per_second=944.52M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/32            76.4 ns         76.4 ns      9081671 bytes_per_second=1.56116G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/64             106 ns          106 ns      6597894 bytes_per_second=2.24352G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/128            188 ns          188 ns      3730743 bytes_per_second=2.54209G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/256            332 ns          332 ns      2105112 bytes_per_second=2.87003G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/512            617 ns          617 ns      1137556 bytes_per_second=3.09093G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1024          1150 ns         1150 ns       608930 bytes_per_second=3.31816G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/2048          2091 ns         2091 ns       335362 bytes_per_second=3.64914G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/4096          4226 ns         4226 ns       165527 bytes_per_second=3.61034G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/8192          9085 ns         9085 ns        76652 bytes_per_second=3.35916G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/16384        16742 ns        16743 ns        41784 bytes_per_second=3.64551G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/32768        35995 ns        35995 ns        19446 bytes_per_second=3.39134G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/65536        75538 ns        75538 ns         9274 bytes_per_second=3.232G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/131072      147954 ns       147953 ns         4732 bytes_per_second=3.30024G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/262144      303051 ns       303051 ns         2311 bytes_per_second=3.22243G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/524288      616691 ns       616675 ns         1131 bytes_per_second=3.16719G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1048576    1484683 ns      1484651 ns          467 bytes_per_second=2.63109G/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1               50.0 ns         50.0 ns     14002165 bytes_per_second=76.3212M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/2               64.4 ns         64.4 ns     10876437 bytes_per_second=118.495M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/4               91.3 ns         91.3 ns      7668867 bytes_per_second=167.147M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/8                177 ns          177 ns      3963762 bytes_per_second=172.615M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/16               310 ns          310 ns      2292012 bytes_per_second=197.185M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/32               609 ns          609 ns      1148670 bytes_per_second=200.313M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/64              1163 ns         1163 ns       601650 bytes_per_second=209.898M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/128             2293 ns         2293 ns       304923 bytes_per_second=212.933M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/256             4517 ns         4517 ns       155378 bytes_per_second=216.191M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/512             8932 ns         8932 ns        78212 bytes_per_second=218.667M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1024           18027 ns        18027 ns        38780 bytes_per_second=216.689M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/2048           35994 ns        35994 ns        19454 bytes_per_second=217.049M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/4096           72149 ns        72150 ns         9696 bytes_per_second=216.562M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/8192          144667 ns       144667 ns         4838 bytes_per_second=216.013M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/16384         290098 ns       290095 ns         2413 bytes_per_second=215.447M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/32768         579696 ns       579696 ns         1198 bytes_per_second=215.63M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/65536        1159696 ns      1159705 ns          600 bytes_per_second=215.572M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/131072       2332802 ns      2332783 ns          299 bytes_per_second=214.336M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/262144       4785784 ns      4785471 ns          134 bytes_per_second=208.966M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/524288       9754347 ns      9753912 ns           66 bytes_per_second=205.046M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1048576     19803208 ns     19802730 ns           33 bytes_per_second=201.992M/s
+BM_format_to_string_begin<std::wstring>/1                             34.5 ns         34.5 ns     20281891 bytes_per_second=110.444M/s
+BM_format_to_string_begin<std::wstring>/2                             35.3 ns         35.3 ns     19824652 bytes_per_second=216.079M/s
+BM_format_to_string_begin<std::wstring>/4                             36.7 ns         36.7 ns     19041818 bytes_per_second=415.284M/s
+BM_format_to_string_begin<std::wstring>/8                             38.8 ns         38.8 ns     18055435 bytes_per_second=786.436M/s
+BM_format_to_string_begin<std::wstring>/16                            43.8 ns         43.8 ns     15963388 bytes_per_second=1.35968G/s
+BM_format_to_string_begin<std::wstring>/32                            62.4 ns         62.4 ns     11247052 bytes_per_second=1.90908G/s
+BM_format_to_string_begin<std::wstring>/64                            83.4 ns         83.4 ns      8423439 bytes_per_second=2.85966G/s
+BM_format_to_string_begin<std::wstring>/128                            132 ns          132 ns      5295989 bytes_per_second=3.60451G/s
+BM_format_to_string_begin<std::wstring>/256                            230 ns          230 ns      3035360 bytes_per_second=4.14004G/s
+BM_format_to_string_begin<std::wstring>/512                            434 ns          434 ns      1612701 bytes_per_second=4.39135G/s
+BM_format_to_string_begin<std::wstring>/1024                           825 ns          825 ns       849783 bytes_per_second=4.62478G/s
+BM_format_to_string_begin<std::wstring>/2048                          1626 ns         1626 ns       430915 bytes_per_second=4.69227G/s
+BM_format_to_string_begin<std::wstring>/4096                          3233 ns         3233 ns       216577 bytes_per_second=4.71931G/s
+BM_format_to_string_begin<std::wstring>/8192                          6758 ns         6758 ns       103013 bytes_per_second=4.51585G/s
+BM_format_to_string_begin<std::wstring>/16384                        13845 ns        13846 ns        50585 bytes_per_second=4.4083G/s
+BM_format_to_string_begin<std::wstring>/32768                        28775 ns        28775 ns        24333 bytes_per_second=4.24228G/s
+BM_format_to_string_begin<std::wstring>/65536                        58631 ns        58631 ns        11929 bytes_per_second=4.16403G/s
+BM_format_to_string_begin<std::wstring>/131072                      115225 ns       115225 ns         6069 bytes_per_second=4.23762G/s
+BM_format_to_string_begin<std::wstring>/262144                      233032 ns       233032 ns         3003 bytes_per_second=4.19068G/s
+BM_format_to_string_begin<std::wstring>/524288                      471247 ns       471246 ns         1486 bytes_per_second=4.14459G/s
+BM_format_to_string_begin<std::wstring>/1048576                     991355 ns       991320 ns          705 bytes_per_second=3.94045G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1                     34.1 ns         34.1 ns     20541846 bytes_per_second=111.951M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/2                     35.1 ns         35.1 ns     19914765 bytes_per_second=217.172M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/4                     37.0 ns         37.0 ns     18931622 bytes_per_second=412.177M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/8                     38.5 ns         38.5 ns     18206615 bytes_per_second=792.961M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/16                    43.3 ns         43.3 ns     16206824 bytes_per_second=1.37653G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/32                    54.6 ns         54.6 ns     12855404 bytes_per_second=2.18355G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/64                    83.2 ns         83.2 ns      8427628 bytes_per_second=2.86704G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/128                    137 ns          137 ns      5114252 bytes_per_second=3.48455G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/256                    230 ns          230 ns      3036360 bytes_per_second=4.13775G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/512                    435 ns          435 ns      1612647 bytes_per_second=4.38954G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1024                   826 ns          826 ns       849588 bytes_per_second=4.62076G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/2048                  1626 ns         1626 ns       429926 bytes_per_second=4.69199G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/4096                  3230 ns         3230 ns       216674 bytes_per_second=4.72453G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/8192                  6746 ns         6747 ns       103669 bytes_per_second=4.52345G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/16384                13841 ns        13841 ns        50591 bytes_per_second=4.40978G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/32768                28767 ns        28767 ns        24342 bytes_per_second=4.24339G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/65536                58620 ns        58620 ns        11947 bytes_per_second=4.16482G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/131072              115254 ns       115254 ns         6076 bytes_per_second=4.23658G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/262144              232975 ns       232975 ns         3005 bytes_per_second=4.19171G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/524288              471006 ns       471007 ns         1486 bytes_per_second=4.1467G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1048576             991621 ns       991587 ns          703 bytes_per_second=3.93939G/s
+BM_format_to_string_begin<std::list<wchar_t>>/1                       36.5 ns         36.5 ns     19199916 bytes_per_second=104.579M/s
+BM_format_to_string_begin<std::list<wchar_t>>/2                       37.5 ns         37.5 ns     18062606 bytes_per_second=203.673M/s
+BM_format_to_string_begin<std::list<wchar_t>>/4                       42.5 ns         42.5 ns     16417795 bytes_per_second=359.091M/s
+BM_format_to_string_begin<std::list<wchar_t>>/8                       56.3 ns         56.3 ns     12433436 bytes_per_second=542.425M/s
+BM_format_to_string_begin<std::list<wchar_t>>/16                      80.8 ns         80.8 ns      8668694 bytes_per_second=755.499M/s
+BM_format_to_string_begin<std::list<wchar_t>>/32                       133 ns          133 ns      5266500 bytes_per_second=918.575M/s
+BM_format_to_string_begin<std::list<wchar_t>>/64                       240 ns          240 ns      2804292 bytes_per_second=1018.8M/s
+BM_format_to_string_begin<std::list<wchar_t>>/128                      457 ns          457 ns      1565280 bytes_per_second=1069.56M/s
+BM_format_to_string_begin<std::list<wchar_t>>/256                      862 ns          862 ns       812582 bytes_per_second=1.10668G/s
+BM_format_to_string_begin<std::list<wchar_t>>/512                     1700 ns         1700 ns       409949 bytes_per_second=1.12166G/s
+BM_format_to_string_begin<std::list<wchar_t>>/1024                    3378 ns         3378 ns       207121 bytes_per_second=1.12942G/s
+BM_format_to_string_begin<std::list<wchar_t>>/2048                    6692 ns         6692 ns       104555 bytes_per_second=1.14008G/s
+BM_format_to_string_begin<std::list<wchar_t>>/4096                   13358 ns        13358 ns        52437 bytes_per_second=1.14227G/s
+BM_format_to_string_begin<std::list<wchar_t>>/8192                   26959 ns        26959 ns        25948 bytes_per_second=1.13198G/s
+BM_format_to_string_begin<std::list<wchar_t>>/16384                  53571 ns        53570 ns        13043 bytes_per_second=1.13936G/s
+BM_format_to_string_begin<std::list<wchar_t>>/32768                 107623 ns       107623 ns         6508 bytes_per_second=1.13423G/s
+BM_format_to_string_begin<std::list<wchar_t>>/65536                 215018 ns       215018 ns         3255 bytes_per_second=1.13544G/s
+BM_format_to_string_begin<std::list<wchar_t>>/131072                442427 ns       442427 ns         1583 bytes_per_second=1.10364G/s
+BM_format_to_string_begin<std::list<wchar_t>>/262144               1009456 ns      1009373 ns          696 bytes_per_second=990.714M/s
+BM_format_to_string_begin<std::list<wchar_t>>/524288               2265916 ns      2265825 ns          309 bytes_per_second=882.681M/s
+BM_format_to_string_begin<std::list<wchar_t>>/1048576              4669321 ns      4669175 ns          150 bytes_per_second=856.682M/s
+BM_format_to_string_span<std::span<wchar_t>>/1                        34.6 ns         34.6 ns     20233040 bytes_per_second=110.257M/s
+BM_format_to_string_span<std::span<wchar_t>>/2                        35.4 ns         35.4 ns     19775495 bytes_per_second=215.557M/s
+BM_format_to_string_span<std::span<wchar_t>>/4                        36.4 ns         36.4 ns     19223533 bytes_per_second=419.165M/s
+BM_format_to_string_span<std::span<wchar_t>>/8                        39.3 ns         39.3 ns     17783865 bytes_per_second=776.261M/s
+BM_format_to_string_span<std::span<wchar_t>>/16                       43.8 ns         43.8 ns     15975236 bytes_per_second=1.36128G/s
+BM_format_to_string_span<std::span<wchar_t>>/32                       56.1 ns         56.1 ns     12462031 bytes_per_second=2.12367G/s
+BM_format_to_string_span<std::span<wchar_t>>/64                       83.1 ns         83.1 ns      8447286 bytes_per_second=2.86877G/s
+BM_format_to_string_span<std::span<wchar_t>>/128                       132 ns          132 ns      5320176 bytes_per_second=3.61368G/s
+BM_format_to_string_span<std::span<wchar_t>>/256                       230 ns          230 ns      3045597 bytes_per_second=4.14673G/s
+BM_format_to_string_span<std::span<wchar_t>>/512                       434 ns          434 ns      1613670 bytes_per_second=4.39676G/s
+BM_format_to_string_span<std::span<wchar_t>>/1024                      825 ns          825 ns       846942 bytes_per_second=4.62245G/s
+BM_format_to_string_span<std::span<wchar_t>>/2048                     1626 ns         1626 ns       431064 bytes_per_second=4.69109G/s
+BM_format_to_string_span<std::span<wchar_t>>/4096                     3238 ns         3238 ns       216619 bytes_per_second=4.71305G/s
+BM_format_to_string_span<std::span<wchar_t>>/8192                     6755 ns         6755 ns       103511 bytes_per_second=4.51804G/s
+BM_format_to_string_span<std::span<wchar_t>>/16384                   13837 ns        13837 ns        50548 bytes_per_second=4.41097G/s
+BM_format_to_string_span<std::span<wchar_t>>/32768                   28732 ns        28732 ns        24346 bytes_per_second=4.24851G/s
+BM_format_to_string_span<std::span<wchar_t>>/65536                   58648 ns        58648 ns        11920 bytes_per_second=4.16278G/s
+BM_format_to_string_span<std::span<wchar_t>>/131072                 116956 ns       116956 ns         5985 bytes_per_second=4.17491G/s
+BM_format_to_string_span<std::span<wchar_t>>/262144                 233795 ns       233796 ns         2994 bytes_per_second=4.17699G/s
+BM_format_to_string_span<std::span<wchar_t>>/524288                 470346 ns       470342 ns         1488 bytes_per_second=4.15257G/s
+BM_format_to_string_span<std::span<wchar_t>>/1048576                991258 ns       991218 ns          706 bytes_per_second=3.94086G/s
+BM_format_to_string_pointer<wchar_t*>/1                               35.0 ns         35.0 ns     19994311 bytes_per_second=108.995M/s
+BM_format_to_string_pointer<wchar_t*>/2                               35.8 ns         35.8 ns     19542372 bytes_per_second=213.214M/s
+BM_format_to_string_pointer<wchar_t*>/4                               36.9 ns         36.9 ns     18956243 bytes_per_second=413.022M/s
+BM_format_to_string_pointer<wchar_t*>/8                               38.8 ns         38.8 ns     18045335 bytes_per_second=787.031M/s
+BM_format_to_string_pointer<wchar_t*>/16                              43.5 ns         43.5 ns     16093718 bytes_per_second=1.37087G/s
+BM_format_to_string_pointer<wchar_t*>/32                              57.7 ns         57.7 ns     12151874 bytes_per_second=2.06477G/s
+BM_format_to_string_pointer<wchar_t*>/64                              81.7 ns         81.7 ns      8557572 bytes_per_second=2.9191G/s
+BM_format_to_string_pointer<wchar_t*>/128                              129 ns          129 ns      5415244 bytes_per_second=3.68752G/s
+BM_format_to_string_pointer<wchar_t*>/256                              232 ns          232 ns      3017067 bytes_per_second=4.11823G/s
+BM_format_to_string_pointer<wchar_t*>/512                              428 ns          428 ns      1638069 bytes_per_second=4.45898G/s
+BM_format_to_string_pointer<wchar_t*>/1024                             812 ns          812 ns       862732 bytes_per_second=4.69599G/s
+BM_format_to_string_pointer<wchar_t*>/2048                            1594 ns         1594 ns       439064 bytes_per_second=4.7861G/s
+BM_format_to_string_pointer<wchar_t*>/4096                            3194 ns         3194 ns       219079 bytes_per_second=4.77722G/s
+BM_format_to_string_pointer<wchar_t*>/8192                            6651 ns         6651 ns       105285 bytes_per_second=4.58822G/s
+BM_format_to_string_pointer<wchar_t*>/16384                          13820 ns        13820 ns        50664 bytes_per_second=4.41656G/s
+BM_format_to_string_pointer<wchar_t*>/32768                          28399 ns        28399 ns        24641 bytes_per_second=4.2984G/s
+BM_format_to_string_pointer<wchar_t*>/65536                          57662 ns        57663 ns        12133 bytes_per_second=4.23394G/s
+BM_format_to_string_pointer<wchar_t*>/131072                        115536 ns       115537 ns         6063 bytes_per_second=4.2262G/s
+BM_format_to_string_pointer<wchar_t*>/262144                        230531 ns       230532 ns         3035 bytes_per_second=4.23613G/s
+BM_format_to_string_pointer<wchar_t*>/524288                        463167 ns       463158 ns         1511 bytes_per_second=4.21698G/s
+BM_format_to_string_pointer<wchar_t*>/1048576                       980395 ns       980365 ns          716 bytes_per_second=3.98449G/s

libcxx/after/format_to_n.txt

+----------------------------------------------------------------------------------------------------------------------------
+Benchmark                                                                  Time             CPU   Iterations UserCounters...
+----------------------------------------------------------------------------------------------------------------------------
+BM_format_to_n_string_back_inserter<std::string>/1                      43.0 ns         43.0 ns     16298933 bytes_per_second=22.198M/s
+BM_format_to_n_string_back_inserter<std::string>/2                      45.5 ns         45.5 ns     15381606 bytes_per_second=41.8941M/s
+BM_format_to_n_string_back_inserter<std::string>/4                      54.1 ns         54.0 ns     12978723 bytes_per_second=70.592M/s
+BM_format_to_n_string_back_inserter<std::string>/8                      68.1 ns         68.0 ns     10284442 bytes_per_second=112.132M/s
+BM_format_to_n_string_back_inserter<std::string>/16                     94.7 ns         94.7 ns      7403981 bytes_per_second=161.178M/s
+BM_format_to_n_string_back_inserter<std::string>/32                      172 ns          172 ns      4074932 bytes_per_second=177.665M/s
+BM_format_to_n_string_back_inserter<std::string>/64                      286 ns          286 ns      2444046 bytes_per_second=213.33M/s
+BM_format_to_n_string_back_inserter<std::string>/128                     533 ns          533 ns      1313292 bytes_per_second=229.217M/s
+BM_format_to_n_string_back_inserter<std::string>/256                    1002 ns         1002 ns       696601 bytes_per_second=243.701M/s
+BM_format_to_n_string_back_inserter<std::string>/512                    1969 ns         1969 ns       355734 bytes_per_second=248.023M/s
+BM_format_to_n_string_back_inserter<std::string>/1024                   3953 ns         3951 ns       177228 bytes_per_second=247.158M/s
+BM_format_to_n_string_back_inserter<std::string>/2048                   7819 ns         7816 ns        89533 bytes_per_second=249.886M/s
+BM_format_to_n_string_back_inserter<std::string>/4096                  15460 ns        15454 ns        45297 bytes_per_second=252.76M/s
+BM_format_to_n_string_back_inserter<std::string>/8192                  30744 ns        30733 ns        22775 bytes_per_second=254.209M/s
+BM_format_to_n_string_back_inserter<std::string>/16384                 61132 ns        61111 ns        11454 bytes_per_second=255.684M/s
+BM_format_to_n_string_back_inserter<std::string>/32768                122016 ns       121965 ns         5740 bytes_per_second=256.221M/s
+BM_format_to_n_string_back_inserter<std::string>/65536                244331 ns       244234 ns         2867 bytes_per_second=255.902M/s
+BM_format_to_n_string_back_inserter<std::string>/131072               489019 ns       488797 ns         1432 bytes_per_second=255.73M/s
+BM_format_to_n_string_back_inserter<std::string>/262144               979745 ns       979327 ns          714 bytes_per_second=255.277M/s
+BM_format_to_n_string_back_inserter<std::string>/524288              1960153 ns      1959250 ns          357 bytes_per_second=255.2M/s
+BM_format_to_n_string_back_inserter<std::string>/1048576             3934827 ns      3934722 ns          178 bytes_per_second=254.148M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1                58.5 ns         58.5 ns     11961042 bytes_per_second=16.2924M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/2                60.0 ns         60.0 ns     11656723 bytes_per_second=31.7849M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/4                64.8 ns         64.8 ns     10818360 bytes_per_second=58.8805M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/8                79.6 ns         79.6 ns      8782721 bytes_per_second=95.8942M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/16                109 ns          109 ns      6452654 bytes_per_second=140.555M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/32                166 ns          166 ns      4216820 bytes_per_second=183.972M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/64                280 ns          280 ns      2510690 bytes_per_second=218.246M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/128               524 ns          524 ns      1333880 bytes_per_second=232.824M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/256               995 ns          995 ns       703384 bytes_per_second=245.447M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/512              1949 ns         1949 ns       359293 bytes_per_second=250.481M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1024             3860 ns         3860 ns       181393 bytes_per_second=252.963M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/2048             7701 ns         7701 ns        91013 bytes_per_second=253.624M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/4096            15311 ns        15312 ns        45629 bytes_per_second=255.117M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/8192            30529 ns        30529 ns        22923 bytes_per_second=255.901M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/16384           60832 ns        60833 ns        11486 bytes_per_second=256.852M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/32768          121422 ns       121422 ns         5762 bytes_per_second=257.366M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/65536          243658 ns       243658 ns         2871 bytes_per_second=256.507M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/131072         487197 ns       487196 ns         1436 bytes_per_second=256.57M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/262144         975357 ns       975363 ns          717 bytes_per_second=256.315M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/524288        1951084 ns      1951093 ns          359 bytes_per_second=256.267M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1048576       3916865 ns      3916838 ns          178 bytes_per_second=255.308M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1                  52.8 ns         52.8 ns     13274607 bytes_per_second=18.0522M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/2                  67.6 ns         67.6 ns     10364051 bytes_per_second=28.2279M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/4                  98.8 ns         98.8 ns      7087550 bytes_per_second=38.6003M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/8                   169 ns          169 ns      4150607 bytes_per_second=45.2364M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/16                  330 ns          330 ns      2119265 bytes_per_second=46.2013M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/32                  677 ns          677 ns      1035183 bytes_per_second=45.0873M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/64                 1315 ns         1315 ns       530628 bytes_per_second=46.4295M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/128                2625 ns         2625 ns       267328 bytes_per_second=46.4996M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/256                5199 ns         5200 ns       134767 bytes_per_second=46.9544M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/512               10367 ns        10367 ns        67503 bytes_per_second=47.0998M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1024              20736 ns        20736 ns        33745 bytes_per_second=47.0939M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/2048              41588 ns        41588 ns        16818 bytes_per_second=46.9634M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/4096              83358 ns        83358 ns         8390 bytes_per_second=46.861M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/8192             167123 ns       167124 ns         4182 bytes_per_second=46.7467M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/16384            334452 ns       334454 ns         2093 bytes_per_second=46.718M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/32768            669253 ns       669255 ns         1042 bytes_per_second=46.6937M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/65536           1339049 ns      1339056 ns          521 bytes_per_second=46.6747M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/131072          2692698 ns      2692620 ns          259 bytes_per_second=46.4232M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/262144          5487797 ns      5487519 ns          118 bytes_per_second=45.5579M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/524288         11141909 ns     11141498 ns           59 bytes_per_second=44.8773M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1048576        22592316 ns     22591621 ns           29 bytes_per_second=44.2642M/s
+BM_format_to_n_string_begin<std::string>/1                              37.7 ns         37.7 ns     18586915 bytes_per_second=25.3112M/s
+BM_format_to_n_string_begin<std::string>/2                              39.9 ns         39.9 ns     17523347 bytes_per_second=47.806M/s
+BM_format_to_n_string_begin<std::string>/4                              46.7 ns         46.7 ns     14963899 bytes_per_second=81.5997M/s
+BM_format_to_n_string_begin<std::string>/8                              62.1 ns         62.1 ns     11280299 bytes_per_second=122.925M/s
+BM_format_to_n_string_begin<std::string>/16                             90.1 ns         90.1 ns      7770033 bytes_per_second=169.378M/s
+BM_format_to_n_string_begin<std::string>/32                              146 ns          146 ns      4806027 bytes_per_second=209.589M/s
+BM_format_to_n_string_begin<std::string>/64                              259 ns          259 ns      2701875 bytes_per_second=235.655M/s
+BM_format_to_n_string_begin<std::string>/128                             502 ns          502 ns      1393858 bytes_per_second=243.154M/s
+BM_format_to_n_string_begin<std::string>/256                             968 ns          968 ns       722965 bytes_per_second=252.319M/s
+BM_format_to_n_string_begin<std::string>/512                            1902 ns         1902 ns       368267 bytes_per_second=256.783M/s
+BM_format_to_n_string_begin<std::string>/1024                           3774 ns         3774 ns       185392 bytes_per_second=258.774M/s
+BM_format_to_n_string_begin<std::string>/2048                           7535 ns         7535 ns        93070 bytes_per_second=259.191M/s
+BM_format_to_n_string_begin<std::string>/4096                          15009 ns        15009 ns        46623 bytes_per_second=260.262M/s
+BM_format_to_n_string_begin<std::string>/8192                          29949 ns        29950 ns        23380 bytes_per_second=260.855M/s
+BM_format_to_n_string_begin<std::string>/16384                         59887 ns        59887 ns        11691 bytes_per_second=260.909M/s
+BM_format_to_n_string_begin<std::string>/32768                        119700 ns       119700 ns         5847 bytes_per_second=261.069M/s
+BM_format_to_n_string_begin<std::string>/65536                        239527 ns       239529 ns         2922 bytes_per_second=260.929M/s
+BM_format_to_n_string_begin<std::string>/131072                       479444 ns       479435 ns         1461 bytes_per_second=260.724M/s
+BM_format_to_n_string_begin<std::string>/262144                       958881 ns       958869 ns          730 bytes_per_second=260.724M/s
+BM_format_to_n_string_begin<std::string>/524288                      1916815 ns      1916822 ns          365 bytes_per_second=260.848M/s
+BM_format_to_n_string_begin<std::string>/1048576                     3838188 ns      3836349 ns          183 bytes_per_second=260.664M/s
+BM_format_to_n_string_begin<std::vector<char>>/1                        36.7 ns         36.7 ns     19053499 bytes_per_second=25.9515M/s
+BM_format_to_n_string_begin<std::vector<char>>/2                        39.1 ns         39.1 ns     17887055 bytes_per_second=48.7798M/s
+BM_format_to_n_string_begin<std::vector<char>>/4                        47.1 ns         47.1 ns     15058753 bytes_per_second=80.9224M/s
+BM_format_to_n_string_begin<std::vector<char>>/8                        62.4 ns         62.4 ns     11379297 bytes_per_second=122.218M/s
+BM_format_to_n_string_begin<std::vector<char>>/16                       89.5 ns         89.5 ns      7826673 bytes_per_second=170.558M/s
+BM_format_to_n_string_begin<std::vector<char>>/32                        146 ns          146 ns      4788018 bytes_per_second=208.39M/s
+BM_format_to_n_string_begin<std::vector<char>>/64                        261 ns          261 ns      2698436 bytes_per_second=234.293M/s
+BM_format_to_n_string_begin<std::vector<char>>/128                       506 ns          506 ns      1388199 bytes_per_second=241.329M/s
+BM_format_to_n_string_begin<std::vector<char>>/256                       968 ns          968 ns       721499 bytes_per_second=252.095M/s
+BM_format_to_n_string_begin<std::vector<char>>/512                      1902 ns         1902 ns       368289 bytes_per_second=256.699M/s
+BM_format_to_n_string_begin<std::vector<char>>/1024                     3776 ns         3776 ns       185286 bytes_per_second=258.648M/s
+BM_format_to_n_string_begin<std::vector<char>>/2048                     7529 ns         7529 ns        93055 bytes_per_second=259.416M/s
+BM_format_to_n_string_begin<std::vector<char>>/4096                    15018 ns        15018 ns        46607 bytes_per_second=260.1M/s
+BM_format_to_n_string_begin<std::vector<char>>/8192                    29943 ns        29943 ns        23364 bytes_per_second=260.914M/s
+BM_format_to_n_string_begin<std::vector<char>>/16384                   59880 ns        59881 ns        11682 bytes_per_second=260.935M/s
+BM_format_to_n_string_begin<std::vector<char>>/32768                  119701 ns       119701 ns         5842 bytes_per_second=261.068M/s
+BM_format_to_n_string_begin<std::vector<char>>/65536                  239391 ns       239392 ns         2920 bytes_per_second=261.078M/s
+BM_format_to_n_string_begin<std::vector<char>>/131072                 479084 ns       479084 ns         1460 bytes_per_second=260.915M/s
+BM_format_to_n_string_begin<std::vector<char>>/262144                 958328 ns       958333 ns          730 bytes_per_second=260.87M/s
+BM_format_to_n_string_begin<std::vector<char>>/524288                1916968 ns      1916971 ns          365 bytes_per_second=260.828M/s
+BM_format_to_n_string_begin<std::vector<char>>/1048576               3833413 ns      3833431 ns          183 bytes_per_second=260.863M/s
+BM_format_to_n_string_begin<std::list<char>>/1                          36.3 ns         36.3 ns     19290199 bytes_per_second=26.2829M/s
+BM_format_to_n_string_begin<std::list<char>>/2                          39.7 ns         39.7 ns     17618771 bytes_per_second=48.0659M/s
+BM_format_to_n_string_begin<std::list<char>>/4                          47.6 ns         47.6 ns     14731849 bytes_per_second=80.1795M/s
+BM_format_to_n_string_begin<std::list<char>>/8                          68.8 ns         68.8 ns     10134995 bytes_per_second=110.854M/s
+BM_format_to_n_string_begin<std::list<char>>/16                          118 ns          118 ns      5940969 bytes_per_second=129.564M/s
+BM_format_to_n_string_begin<std::list<char>>/32                          221 ns          221 ns      3163721 bytes_per_second=137.901M/s
+BM_format_to_n_string_begin<std::list<char>>/64                          419 ns          419 ns      1670380 bytes_per_second=145.665M/s
+BM_format_to_n_string_begin<std::list<char>>/128                         829 ns          829 ns       844229 bytes_per_second=147.235M/s
+BM_format_to_n_string_begin<std::list<char>>/256                        1637 ns         1637 ns       428335 bytes_per_second=149.115M/s
+BM_format_to_n_string_begin<std::list<char>>/512                        3244 ns         3244 ns       215738 bytes_per_second=150.528M/s
+BM_format_to_n_string_begin<std::list<char>>/1024                       6491 ns         6491 ns       107708 bytes_per_second=150.446M/s
+BM_format_to_n_string_begin<std::list<char>>/2048                      12920 ns        12920 ns        54184 bytes_per_second=151.171M/s
+BM_format_to_n_string_begin<std::list<char>>/4096                      25775 ns        25775 ns        27187 bytes_per_second=151.553M/s
+BM_format_to_n_string_begin<std::list<char>>/8192                      51635 ns        51635 ns        13557 bytes_per_second=151.303M/s
+BM_format_to_n_string_begin<std::list<char>>/16384                    103194 ns       103194 ns         6786 bytes_per_second=151.414M/s
+BM_format_to_n_string_begin<std::list<char>>/32768                    206290 ns       206289 ns         3394 bytes_per_second=151.486M/s
+BM_format_to_n_string_begin<std::list<char>>/65536                    412497 ns       412496 ns         1698 bytes_per_second=151.516M/s
+BM_format_to_n_string_begin<std::list<char>>/131072                   835730 ns       835724 ns          838 bytes_per_second=149.571M/s
+BM_format_to_n_string_begin<std::list<char>>/262144                  1780349 ns      1780275 ns          394 bytes_per_second=140.428M/s
+BM_format_to_n_string_begin<std::list<char>>/524288                  3730561 ns      3730385 ns          188 bytes_per_second=134.034M/s
+BM_format_to_n_string_begin<std::list<char>>/1048576                 7513556 ns      7513003 ns           93 bytes_per_second=133.103M/s
+BM_format_to_n_string_span<std::span<char>>/1                           37.6 ns         37.6 ns     18612324 bytes_per_second=25.3594M/s
+BM_format_to_n_string_span<std::span<char>>/2                           39.6 ns         39.6 ns     17710114 bytes_per_second=48.2072M/s
+BM_format_to_n_string_span<std::span<char>>/4                           46.1 ns         46.1 ns     15199801 bytes_per_second=82.756M/s
+BM_format_to_n_string_span<std::span<char>>/8                           61.9 ns         61.9 ns     11560676 bytes_per_second=123.237M/s
+BM_format_to_n_string_span<std::span<char>>/16                          89.2 ns         89.2 ns      7849153 bytes_per_second=171.143M/s
+BM_format_to_n_string_span<std::span<char>>/32                           146 ns          146 ns      4806761 bytes_per_second=209.683M/s
+BM_format_to_n_string_span<std::span<char>>/64                           259 ns          259 ns      2700170 bytes_per_second=235.435M/s
+BM_format_to_n_string_span<std::span<char>>/128                          502 ns          502 ns      1394013 bytes_per_second=243.288M/s
+BM_format_to_n_string_span<std::span<char>>/256                          968 ns          968 ns       723252 bytes_per_second=252.09M/s
+BM_format_to_n_string_span<std::span<char>>/512                         1901 ns         1901 ns       368283 bytes_per_second=256.839M/s
+BM_format_to_n_string_span<std::span<char>>/1024                        3775 ns         3775 ns       185355 bytes_per_second=258.69M/s
+BM_format_to_n_string_span<std::span<char>>/2048                        7535 ns         7535 ns        92856 bytes_per_second=259.204M/s
+BM_format_to_n_string_span<std::span<char>>/4096                       15012 ns        15012 ns        46625 bytes_per_second=260.213M/s
+BM_format_to_n_string_span<std::span<char>>/8192                       29951 ns        29951 ns        23370 bytes_per_second=260.845M/s
+BM_format_to_n_string_span<std::span<char>>/16384                      59870 ns        59870 ns        11701 bytes_per_second=260.982M/s
+BM_format_to_n_string_span<std::span<char>>/32768                     119695 ns       119695 ns         5830 bytes_per_second=261.08M/s
+BM_format_to_n_string_span<std::span<char>>/65536                     239428 ns       239428 ns         2923 bytes_per_second=261.039M/s
+BM_format_to_n_string_span<std::span<char>>/131072                    479188 ns       479189 ns         1460 bytes_per_second=260.857M/s
+BM_format_to_n_string_span<std::span<char>>/262144                    958740 ns       958724 ns          726 bytes_per_second=260.763M/s
+BM_format_to_n_string_span<std::span<char>>/524288                   1916538 ns      1916531 ns          365 bytes_per_second=260.888M/s
+BM_format_to_n_string_span<std::span<char>>/1048576                  3832811 ns      3832803 ns          183 bytes_per_second=260.906M/s
+BM_format_to_n_string_pointer<char*>/1                                  37.6 ns         37.6 ns     18593293 bytes_per_second=25.3552M/s
+BM_format_to_n_string_pointer<char*>/2                                  39.5 ns         39.5 ns     17708189 bytes_per_second=48.2452M/s
+BM_format_to_n_string_pointer<char*>/4                                  46.2 ns         46.2 ns     15049057 bytes_per_second=82.501M/s
+BM_format_to_n_string_pointer<char*>/8                                  61.5 ns         61.5 ns     11287196 bytes_per_second=124.094M/s
+BM_format_to_n_string_pointer<char*>/16                                 88.6 ns         88.6 ns      7899296 bytes_per_second=172.14M/s
+BM_format_to_n_string_pointer<char*>/32                                  146 ns          146 ns      4807951 bytes_per_second=209.657M/s
+BM_format_to_n_string_pointer<char*>/64                                  259 ns          259 ns      2698031 bytes_per_second=235.261M/s
+BM_format_to_n_string_pointer<char*>/128                                 503 ns          503 ns      1392883 bytes_per_second=242.837M/s
+BM_format_to_n_string_pointer<char*>/256                                 968 ns          968 ns       724206 bytes_per_second=252.258M/s
+BM_format_to_n_string_pointer<char*>/512                                1903 ns         1903 ns       368251 bytes_per_second=256.637M/s
+BM_format_to_n_string_pointer<char*>/1024                               3780 ns         3780 ns       185153 bytes_per_second=258.361M/s
+BM_format_to_n_string_pointer<char*>/2048                               7529 ns         7529 ns        92978 bytes_per_second=259.401M/s
+BM_format_to_n_string_pointer<char*>/4096                              15007 ns        15007 ns        46621 bytes_per_second=260.29M/s
+BM_format_to_n_string_pointer<char*>/8192                              29944 ns        29945 ns        23346 bytes_per_second=260.899M/s
+BM_format_to_n_string_pointer<char*>/16384                             59855 ns        59855 ns        11697 bytes_per_second=261.048M/s
+BM_format_to_n_string_pointer<char*>/32768                            119709 ns       119709 ns         5835 bytes_per_second=261.049M/s
+BM_format_to_n_string_pointer<char*>/65536                            239608 ns       239608 ns         2923 bytes_per_second=260.843M/s
+BM_format_to_n_string_pointer<char*>/131072                           479204 ns       479207 ns         1460 bytes_per_second=260.848M/s
+BM_format_to_n_string_pointer<char*>/262144                           958619 ns       958624 ns          730 bytes_per_second=260.79M/s
+BM_format_to_n_string_pointer<char*>/524288                          1917858 ns      1917851 ns          365 bytes_per_second=260.708M/s
+BM_format_to_n_string_pointer<char*>/1048576                         3833926 ns      3833939 ns          183 bytes_per_second=260.828M/s
+BM_format_to_n_string_back_inserter<std::wstring>/1                     42.4 ns         42.4 ns     16474937 bytes_per_second=90.0143M/s
+BM_format_to_n_string_back_inserter<std::wstring>/2                     44.4 ns         44.4 ns     15764625 bytes_per_second=171.976M/s
+BM_format_to_n_string_back_inserter<std::wstring>/4                     47.1 ns         47.1 ns     14847345 bytes_per_second=323.693M/s
+BM_format_to_n_string_back_inserter<std::wstring>/8                     79.7 ns         79.7 ns      8907213 bytes_per_second=382.772M/s
+BM_format_to_n_string_back_inserter<std::wstring>/16                    90.6 ns         90.6 ns      7684384 bytes_per_second=674.028M/s
+BM_format_to_n_string_back_inserter<std::wstring>/32                     114 ns          114 ns      6115428 bytes_per_second=1070.46M/s
+BM_format_to_n_string_back_inserter<std::wstring>/64                     164 ns          164 ns      4284905 bytes_per_second=1.45719G/s
+BM_format_to_n_string_back_inserter<std::wstring>/128                    292 ns          292 ns      2399381 bytes_per_second=1.63318G/s
+BM_format_to_n_string_back_inserter<std::wstring>/256                    581 ns          581 ns      1201675 bytes_per_second=1.64263G/s
+BM_format_to_n_string_back_inserter<std::wstring>/512                   1086 ns         1086 ns       644709 bytes_per_second=1.75611G/s
+BM_format_to_n_string_back_inserter<std::wstring>/1024                  2035 ns         2035 ns       344216 bytes_per_second=1.87439G/s
+BM_format_to_n_string_back_inserter<std::wstring>/2048                  3898 ns         3898 ns       179549 bytes_per_second=1.95735G/s
+BM_format_to_n_string_back_inserter<std::wstring>/4096                  7463 ns         7463 ns        93778 bytes_per_second=2.04453G/s
+BM_format_to_n_string_back_inserter<std::wstring>/8192                 14843 ns        14843 ns        47078 bytes_per_second=2.05603G/s
+BM_format_to_n_string_back_inserter<std::wstring>/16384                30431 ns        30431 ns        22980 bytes_per_second=2.00566G/s
+BM_format_to_n_string_back_inserter<std::wstring>/32768                61726 ns        61725 ns        11282 bytes_per_second=1.97763G/s
+BM_format_to_n_string_back_inserter<std::wstring>/65536               124416 ns       124414 ns         5629 bytes_per_second=1.96233G/s
+BM_format_to_n_string_back_inserter<std::wstring>/131072              250476 ns       250475 ns         2797 bytes_per_second=1.94942G/s
+BM_format_to_n_string_back_inserter<std::wstring>/262144              516075 ns       516057 ns         1348 bytes_per_second=1.89235G/s
+BM_format_to_n_string_back_inserter<std::wstring>/524288             1090363 ns      1090333 ns          638 bytes_per_second=1.79131G/s
+BM_format_to_n_string_back_inserter<std::wstring>/1048576            2424465 ns      2424344 ns          290 bytes_per_second=1.61126G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1             59.9 ns         59.9 ns     11661508 bytes_per_second=63.6404M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/2             60.7 ns         60.7 ns     11494008 bytes_per_second=125.654M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/4             63.9 ns         63.9 ns     10927578 bytes_per_second=238.733M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/8             68.0 ns         68.0 ns     10309671 bytes_per_second=449.073M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/16            78.0 ns         78.0 ns      8925621 bytes_per_second=782.421M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/32             107 ns          107 ns      6518919 bytes_per_second=1.10967G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/64             154 ns          154 ns      4542639 bytes_per_second=1.54541G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/128            274 ns          274 ns      2555460 bytes_per_second=1.73747G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/256            504 ns          504 ns      1387090 bytes_per_second=1.8915G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/512            993 ns          993 ns       706257 bytes_per_second=1.92093G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1024          1884 ns         1884 ns       371507 bytes_per_second=2.02453G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/2048          3695 ns         3695 ns       189394 bytes_per_second=2.06492G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/4096          7262 ns         7262 ns        96216 bytes_per_second=2.10125G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/8192         14445 ns        14445 ns        48443 bytes_per_second=2.11264G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/16384        30191 ns        30191 ns        23208 bytes_per_second=2.0216G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/32768        60072 ns        60072 ns        11594 bytes_per_second=2.03205G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/65536       122458 ns       122458 ns         5715 bytes_per_second=1.99367G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/131072      242334 ns       242334 ns         2893 bytes_per_second=2.01491G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/262144      495531 ns       495526 ns         1412 bytes_per_second=1.97076G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/524288     1053780 ns      1053752 ns          664 bytes_per_second=1.8535G/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1048576    2328952 ns      2328846 ns          300 bytes_per_second=1.67733G/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1               53.1 ns         53.1 ns     13167813 bytes_per_second=71.7983M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/2               70.5 ns         70.5 ns      9827950 bytes_per_second=108.189M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/4                106 ns          106 ns      6569485 bytes_per_second=143.711M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/8                167 ns          167 ns      4205085 bytes_per_second=183.22M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/16               313 ns          313 ns      2233760 bytes_per_second=194.809M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/32               634 ns          634 ns      1107620 bytes_per_second=192.505M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/64              1215 ns         1215 ns       571029 bytes_per_second=200.931M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/128             2381 ns         2381 ns       293934 bytes_per_second=205.112M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/256             4719 ns         4719 ns       148318 bytes_per_second=206.927M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/512             9441 ns         9441 ns        74162 bytes_per_second=206.882M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1024           18902 ns        18902 ns        37004 bytes_per_second=206.656M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/2048           37822 ns        37822 ns        18507 bytes_per_second=206.561M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/4096           75566 ns        75566 ns         9259 bytes_per_second=206.772M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/8192          151839 ns       151835 ns         4601 bytes_per_second=205.815M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/16384         303789 ns       303789 ns         2300 bytes_per_second=205.735M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/32768         607455 ns       607458 ns         1146 bytes_per_second=205.776M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/65536        1217963 ns      1217957 ns          572 bytes_per_second=205.262M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/131072       2449037 ns      2449017 ns          285 bytes_per_second=204.164M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/262144       5010010 ns      5009680 ns          133 bytes_per_second=199.614M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/524288      10234916 ns     10234539 ns           63 bytes_per_second=195.417M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1048576     20769026 ns     20768298 ns           32 bytes_per_second=192.601M/s
+BM_format_to_n_string_begin<std::wstring>/1                             38.7 ns         38.7 ns     18086570 bytes_per_second=98.5679M/s
+BM_format_to_n_string_begin<std::wstring>/2                             39.9 ns         39.9 ns     17575929 bytes_per_second=191.381M/s
+BM_format_to_n_string_begin<std::wstring>/4                             41.4 ns         41.4 ns     16917873 bytes_per_second=368.68M/s
+BM_format_to_n_string_begin<std::wstring>/8                             46.6 ns         46.6 ns     14986752 bytes_per_second=654.538M/s
+BM_format_to_n_string_begin<std::wstring>/16                            58.7 ns         58.7 ns     11962448 bytes_per_second=1040.51M/s
+BM_format_to_n_string_begin<std::wstring>/32                            84.3 ns         84.3 ns      8291840 bytes_per_second=1.41366G/s
+BM_format_to_n_string_begin<std::wstring>/64                             130 ns          130 ns      5368063 bytes_per_second=1.83292G/s
+BM_format_to_n_string_begin<std::wstring>/128                            225 ns          225 ns      3117001 bytes_per_second=2.12393G/s
+BM_format_to_n_string_begin<std::wstring>/256                            426 ns          426 ns      1639721 bytes_per_second=2.24091G/s
+BM_format_to_n_string_begin<std::wstring>/512                            819 ns          819 ns       855219 bytes_per_second=2.33024G/s
+BM_format_to_n_string_begin<std::wstring>/1024                          1586 ns         1586 ns       440692 bytes_per_second=2.405G/s
+BM_format_to_n_string_begin<std::wstring>/2048                          3098 ns         3098 ns       225599 bytes_per_second=2.46276G/s
+BM_format_to_n_string_begin<std::wstring>/4096                          6390 ns         6390 ns       109513 bytes_per_second=2.38794G/s
+BM_format_to_n_string_begin<std::wstring>/8192                         12792 ns        12792 ns        54674 bytes_per_second=2.38568G/s
+BM_format_to_n_string_begin<std::wstring>/16384                        25112 ns        25112 ns        27907 bytes_per_second=2.43053G/s
+BM_format_to_n_string_begin<std::wstring>/32768                        53710 ns        53711 ns        13039 bytes_per_second=2.27274G/s
+BM_format_to_n_string_begin<std::wstring>/65536                       107457 ns       107456 ns         6521 bytes_per_second=2.272G/s
+BM_format_to_n_string_begin<std::wstring>/131072                      215102 ns       215099 ns         3253 bytes_per_second=2.27003G/s
+BM_format_to_n_string_begin<std::wstring>/262144                      430360 ns       430358 ns         1626 bytes_per_second=2.26919G/s
+BM_format_to_n_string_begin<std::wstring>/524288                      886104 ns       886081 ns          790 bytes_per_second=2.20423G/s
+BM_format_to_n_string_begin<std::wstring>/1048576                    1868083 ns      1868001 ns          375 bytes_per_second=2.09114G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1                     37.0 ns         37.0 ns     18929499 bytes_per_second=103.093M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/2                     37.9 ns         37.9 ns     18456408 bytes_per_second=201.151M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/4                     40.3 ns         40.3 ns     17391902 bytes_per_second=378.942M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/8                     46.0 ns         46.0 ns     15214399 bytes_per_second=662.883M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/16                    57.4 ns         57.4 ns     12263418 bytes_per_second=1062.96M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/32                    83.4 ns         83.4 ns      8375162 bytes_per_second=1.42858G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/64                     129 ns          129 ns      5396892 bytes_per_second=1.84209G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/128                    224 ns          224 ns      3127144 bytes_per_second=2.13083G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/256                    419 ns          419 ns      1671611 bytes_per_second=2.27849G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/512                    819 ns          819 ns       854875 bytes_per_second=2.32824G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1024                  1588 ns         1588 ns       440838 bytes_per_second=2.40289G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/2048                  3097 ns         3097 ns       225429 bytes_per_second=2.46317G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/4096                  6393 ns         6393 ns       109437 bytes_per_second=2.38695G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/8192                 12780 ns        12780 ns        54718 bytes_per_second=2.38793G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/16384                24940 ns        24939 ns        28077 bytes_per_second=2.44734G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/32768                53054 ns        53054 ns        13178 bytes_per_second=2.30088G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/65536               106055 ns       106055 ns         6586 bytes_per_second=2.30202G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/131072              212309 ns       212310 ns         3295 bytes_per_second=2.29985G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/262144              425046 ns       425047 ns         1646 bytes_per_second=2.29754G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/524288              875911 ns       875891 ns          801 bytes_per_second=2.22987G/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1048576            1846815 ns      1846749 ns          379 bytes_per_second=2.1152G/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1                       36.4 ns         36.4 ns     19227666 bytes_per_second=104.832M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/2                       39.3 ns         39.3 ns     17814491 bytes_per_second=194.331M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/4                       46.6 ns         46.6 ns     15025186 bytes_per_second=327.682M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/8                       60.4 ns         60.4 ns     11601110 bytes_per_second=505.333M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/16                      96.9 ns         96.9 ns      7225561 bytes_per_second=629.584M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/32                       158 ns          158 ns      4445046 bytes_per_second=774.964M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/64                       290 ns          290 ns      2413600 bytes_per_second=842.297M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/128                      550 ns          550 ns      1272482 bytes_per_second=887.06M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/256                     1065 ns         1065 ns       657573 bytes_per_second=917.31M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/512                     2099 ns         2099 ns       333421 bytes_per_second=930.572M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1024                    4151 ns         4151 ns       168665 bytes_per_second=941.101M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/2048                    8220 ns         8220 ns        85191 bytes_per_second=950.369M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/4096                   16436 ns        16436 ns        42582 bytes_per_second=950.647M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/8192                   32978 ns        32978 ns        21203 bytes_per_second=947.599M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/16384                  65851 ns        65851 ns        10636 bytes_per_second=949.118M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/32768                 131357 ns       131357 ns         5328 bytes_per_second=951.606M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/65536                 262830 ns       262831 ns         2663 bytes_per_second=951.18M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/131072                541366 ns       541361 ns         1290 bytes_per_second=923.598M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/262144               1207598 ns      1207549 ns          580 bytes_per_second=828.124M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/524288               2581522 ns      2581344 ns          271 bytes_per_second=774.79M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1048576              5279779 ns      5279587 ns          133 bytes_per_second=757.635M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/1                        37.9 ns         37.9 ns     18535600 bytes_per_second=100.723M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/2                        38.6 ns         38.6 ns     18149788 bytes_per_second=197.575M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/4                        42.3 ns         42.3 ns     16553233 bytes_per_second=360.564M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/8                        46.5 ns         46.5 ns     15049500 bytes_per_second=655.94M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/16                       59.5 ns         59.5 ns     11771599 bytes_per_second=1025.99M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/32                       83.9 ns         83.9 ns      8380621 bytes_per_second=1.42089G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/64                        130 ns          130 ns      5403109 bytes_per_second=1.83727G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/128                       224 ns          224 ns      3127418 bytes_per_second=2.12714G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/256                       426 ns          426 ns      1644735 bytes_per_second=2.23924G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/512                       819 ns          819 ns       852783 bytes_per_second=2.32985G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/1024                     1586 ns         1586 ns       441528 bytes_per_second=2.40544G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/2048                     3098 ns         3098 ns       225550 bytes_per_second=2.46279G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/4096                     6395 ns         6395 ns       109480 bytes_per_second=2.38603G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/8192                    12786 ns        12785 ns        54459 bytes_per_second=2.38692G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/16384                   25091 ns        25091 ns        27894 bytes_per_second=2.43251G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/32768                   53739 ns        53737 ns        13023 bytes_per_second=2.2716G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/65536                  106749 ns       106749 ns         6556 bytes_per_second=2.28706G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/131072                 214645 ns       214645 ns         3262 bytes_per_second=2.27483G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/262144                 430088 ns       430088 ns         1628 bytes_per_second=2.27061G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/524288                 885497 ns       885445 ns          790 bytes_per_second=2.20581G/s
+BM_format_to_n_string_span<std::span<wchar_t>>/1048576               1866425 ns      1866292 ns          376 bytes_per_second=2.09305G/s
+BM_format_to_n_string_pointer<wchar_t*>/1                               37.8 ns         37.8 ns     18547000 bytes_per_second=100.922M/s
+BM_format_to_n_string_pointer<wchar_t*>/2                               39.0 ns         39.0 ns     17970649 bytes_per_second=195.671M/s
+BM_format_to_n_string_pointer<wchar_t*>/4                               42.2 ns         42.2 ns     16579398 bytes_per_second=361.247M/s
+BM_format_to_n_string_pointer<wchar_t*>/8                               46.6 ns         46.6 ns     15024949 bytes_per_second=655.004M/s
+BM_format_to_n_string_pointer<wchar_t*>/16                              59.5 ns         59.5 ns     11770744 bytes_per_second=1026.38M/s
+BM_format_to_n_string_pointer<wchar_t*>/32                              84.6 ns         84.6 ns      8300914 bytes_per_second=1.40878G/s
+BM_format_to_n_string_pointer<wchar_t*>/64                               130 ns          130 ns      5394632 bytes_per_second=1.83702G/s
+BM_format_to_n_string_pointer<wchar_t*>/128                              224 ns          224 ns      3108546 bytes_per_second=2.12698G/s
+BM_format_to_n_string_pointer<wchar_t*>/256                              425 ns          425 ns      1647166 bytes_per_second=2.24206G/s
+BM_format_to_n_string_pointer<wchar_t*>/512                              818 ns          818 ns       856073 bytes_per_second=2.33129G/s
+BM_format_to_n_string_pointer<wchar_t*>/1024                            1586 ns         1586 ns       440781 bytes_per_second=2.40559G/s
+BM_format_to_n_string_pointer<wchar_t*>/2048                            3104 ns         3104 ns       225660 bytes_per_second=2.45769G/s
+BM_format_to_n_string_pointer<wchar_t*>/4096                            6393 ns         6393 ns       109410 bytes_per_second=2.38663G/s
+BM_format_to_n_string_pointer<wchar_t*>/8192                           12799 ns        12799 ns        54600 bytes_per_second=2.38435G/s
+BM_format_to_n_string_pointer<wchar_t*>/16384                          25099 ns        25099 ns        27892 bytes_per_second=2.4318G/s
+BM_format_to_n_string_pointer<wchar_t*>/32768                          53728 ns        53728 ns        13046 bytes_per_second=2.27203G/s
+BM_format_to_n_string_pointer<wchar_t*>/65536                         106777 ns       106778 ns         6560 bytes_per_second=2.28644G/s
+BM_format_to_n_string_pointer<wchar_t*>/131072                        214667 ns       214666 ns         3256 bytes_per_second=2.27461G/s
+BM_format_to_n_string_pointer<wchar_t*>/262144                        430013 ns       430012 ns         1628 bytes_per_second=2.27101G/s
+BM_format_to_n_string_pointer<wchar_t*>/524288                        886103 ns       886090 ns          790 bytes_per_second=2.20421G/s
+BM_format_to_n_string_pointer<wchar_t*>/1048576                      1867337 ns      1867284 ns          373 bytes_per_second=2.09194G/s

libcxx/after/formatted_size.txt

+----------------------------------------------------------------------------------------------------
+Benchmark                                          Time             CPU   Iterations UserCounters...
+----------------------------------------------------------------------------------------------------
+BM_formatted_size_string<char>/1                32.4 ns         32.4 ns     21598493 bytes_per_second=29.4176M/s
+BM_formatted_size_string<char>/2                16.8 ns         16.8 ns     41723546 bytes_per_second=113.704M/s
+BM_formatted_size_string<char>/4                9.02 ns         9.02 ns     77627068 bytes_per_second=423.117M/s
+BM_formatted_size_string<char>/8                5.51 ns         5.51 ns    127094016 bytes_per_second=1.35335G/s
+BM_formatted_size_string<char>/16               3.68 ns         3.68 ns    190570112 bytes_per_second=4.04464G/s
+BM_formatted_size_string<char>/32               2.73 ns         2.73 ns    255864544 bytes_per_second=10.9089G/s
+BM_formatted_size_string<char>/64               2.25 ns         2.25 ns    310573440 bytes_per_second=26.449G/s
+BM_formatted_size_string<char>/128              2.02 ns         2.02 ns    345991808 bytes_per_second=58.9085G/s
+BM_formatted_size_string<char>/256              1.95 ns         1.95 ns    355650048 bytes_per_second=122.054G/s
+BM_formatted_size_string<char>/512              1.89 ns         1.89 ns    370622464 bytes_per_second=252.329G/s
+BM_formatted_size_string<char>/1024             1.85 ns         1.85 ns    377767936 bytes_per_second=514.465G/s
+BM_formatted_size_string<char>/2048             1.83 ns         1.83 ns    382072832 bytes_per_second=1040.47G/s
+BM_formatted_size_string<char>/4096             1.82 ns         1.82 ns    384032768 bytes_per_second=2.04741T/s
+BM_formatted_size_string<char>/8192             1.81 ns         1.81 ns    386129920 bytes_per_second=4.11172T/s
+BM_formatted_size_string<char>/16384            1.81 ns         1.81 ns    386662400 bytes_per_second=8.23601T/s
+BM_formatted_size_string<char>/32768            1.81 ns         1.81 ns    387383296 bytes_per_second=16.4877T/s
+BM_formatted_size_string<char>/65536            1.81 ns         1.81 ns    387317760 bytes_per_second=32.9732T/s
+BM_formatted_size_string<char>/131072           1.81 ns         1.81 ns    387317760 bytes_per_second=65.9684T/s
+BM_formatted_size_string<char>/262144           1.81 ns         1.81 ns    386924544 bytes_per_second=131.924T/s
+BM_formatted_size_string<char>/524288           1.81 ns         1.81 ns    387448832 bytes_per_second=263.952T/s
+BM_formatted_size_string<char>/1048576          1.81 ns         1.81 ns    387973120 bytes_per_second=527.955T/s
+BM_formatted_size_string<wchar_t>/1             32.4 ns         32.4 ns     21529673 bytes_per_second=117.617M/s
+BM_formatted_size_string<wchar_t>/2             16.6 ns         16.6 ns     42132806 bytes_per_second=458.84M/s
+BM_formatted_size_string<wchar_t>/4             8.63 ns         8.63 ns     81081180 bytes_per_second=1.72651G/s
+BM_formatted_size_string<wchar_t>/8             4.63 ns         4.63 ns    151535056 bytes_per_second=6.44197G/s
+BM_formatted_size_string<wchar_t>/16            2.59 ns         2.59 ns    270219296 bytes_per_second=23.0252G/s
+BM_formatted_size_string<wchar_t>/32            1.59 ns         1.59 ns    438878432 bytes_per_second=74.8853G/s
+BM_formatted_size_string<wchar_t>/64            1.22 ns         1.22 ns    572460096 bytes_per_second=195.489G/s
+BM_formatted_size_string<wchar_t>/128          0.955 ns        0.955 ns    733116160 bytes_per_second=499.387G/s
+BM_formatted_size_string<wchar_t>/256          0.829 ns        0.829 ns    845439488 bytes_per_second=1.12356T/s
+BM_formatted_size_string<wchar_t>/512          0.769 ns        0.769 ns    910455296 bytes_per_second=2.42167T/s
+BM_formatted_size_string<wchar_t>/1024         0.730 ns        0.730 ns    957693952 bytes_per_second=5.10579T/s
+BM_formatted_size_string<wchar_t>/2048         0.711 ns        0.711 ns    984363008 bytes_per_second=10.4734T/s
+BM_formatted_size_string<wchar_t>/4096         0.702 ns        0.702 ns    998043648 bytes_per_second=21.2359T/s
+BM_formatted_size_string<wchar_t>/8192         0.699 ns        0.699 ns   1000005632 bytes_per_second=42.6543T/s
+BM_formatted_size_string<wchar_t>/16384        0.698 ns        0.698 ns   1000013824 bytes_per_second=85.4246T/s
+BM_formatted_size_string<wchar_t>/32768        0.696 ns        0.696 ns   1000013824 bytes_per_second=171.246T/s
+BM_formatted_size_string<wchar_t>/65536        0.695 ns        0.695 ns   1000013824 bytes_per_second=343.038T/s
+BM_formatted_size_string<wchar_t>/131072       0.693 ns        0.693 ns   1000079360 bytes_per_second=687.883T/s
+BM_formatted_size_string<wchar_t>/262144       0.693 ns        0.693 ns   1000079360 bytes_per_second=1.34414P/s
+BM_formatted_size_string<wchar_t>/524288       0.692 ns        0.692 ns   1000341504 bytes_per_second=2.69005P/s
+BM_formatted_size_string<wchar_t>/1048576      0.693 ns        0.693 ns   1000341504 bytes_per_second=5.37523P/s

libcxx/before/format.txt

+--------------------------------------------------------------------------------------------
+Benchmark                                  Time             CPU   Iterations UserCounters...
+--------------------------------------------------------------------------------------------
+BM_format_string<char>/1                42.2 ns         42.2 ns     16569674 bytes_per_second=22.6014M/s
+BM_format_string<char>/2                22.1 ns         22.1 ns     31741352 bytes_per_second=86.4756M/s
+BM_format_string<char>/4                12.1 ns         12.1 ns     57789660 bytes_per_second=314.611M/s
+BM_format_string<char>/8                7.04 ns         7.04 ns     99510768 bytes_per_second=1084.22M/s
+BM_format_string<char>/16               4.48 ns         4.48 ns    156531072 bytes_per_second=3.32906G/s
+BM_format_string<char>/32               3.95 ns         3.94 ns    177596896 bytes_per_second=7.55626G/s
+BM_format_string<char>/64               3.23 ns         3.23 ns    216913408 bytes_per_second=18.4639G/s
+BM_format_string<char>/128              2.71 ns         2.71 ns    257868672 bytes_per_second=43.9468G/s
+BM_format_string<char>/256              2.45 ns         2.45 ns    285697280 bytes_per_second=97.2903G/s
+BM_format_string<char>/512              2.39 ns         2.39 ns    293160960 bytes_per_second=199.797G/s
+BM_format_string<char>/1024             2.38 ns         2.38 ns    294042624 bytes_per_second=400.679G/s
+BM_format_string<char>/2048             2.36 ns         2.36 ns    297142272 bytes_per_second=809.644G/s
+BM_format_string<char>/4096             2.31 ns         2.30 ns    303648768 bytes_per_second=1.61679T/s
+BM_format_string<char>/8192             2.29 ns         2.29 ns    305897472 bytes_per_second=3.25398T/s
+BM_format_string<char>/16384            2.29 ns         2.29 ns    306020352 bytes_per_second=6.51932T/s
+BM_format_string<char>/32768            2.28 ns         2.28 ns    306905088 bytes_per_second=13.0609T/s
+BM_format_string<char>/65536            2.33 ns         2.33 ns    300482560 bytes_per_second=25.5889T/s
+BM_format_string<char>/131072           2.60 ns         2.60 ns    269615104 bytes_per_second=45.904T/s
+BM_format_string<char>/262144           2.71 ns         2.71 ns    258211840 bytes_per_second=88.0239T/s
+BM_format_string<char>/524288           2.76 ns         2.76 ns    253231104 bytes_per_second=172.706T/s
+BM_format_string<char>/1048576          2.80 ns         2.79 ns    250609664 bytes_per_second=341.317T/s
+BM_format_string<wchar_t>/1             39.6 ns         39.6 ns     17674280 bytes_per_second=96.2655M/s
+BM_format_string<wchar_t>/2             20.6 ns         20.6 ns     33903786 bytes_per_second=369.672M/s
+BM_format_string<wchar_t>/4             11.5 ns         11.5 ns     61029212 bytes_per_second=1.29816G/s
+BM_format_string<wchar_t>/8             9.88 ns         9.87 ns     70804848 bytes_per_second=3.01854G/s
+BM_format_string<wchar_t>/16            5.94 ns         5.94 ns    117722976 bytes_per_second=10.0317G/s
+BM_format_string<wchar_t>/32            3.97 ns         3.97 ns    176390496 bytes_per_second=30.0407G/s
+BM_format_string<wchar_t>/64            3.26 ns         3.26 ns    214762880 bytes_per_second=73.201G/s
+BM_format_string<wchar_t>/128           3.07 ns         3.07 ns    227731840 bytes_per_second=155.478G/s
+BM_format_string<wchar_t>/256           2.99 ns         2.99 ns    233409536 bytes_per_second=318.95G/s
+BM_format_string<wchar_t>/512           2.90 ns         2.90 ns    240894976 bytes_per_second=657.67G/s
+BM_format_string<wchar_t>/1024          2.70 ns         2.70 ns    259237888 bytes_per_second=1.37986T/s
+BM_format_string<wchar_t>/2048          2.62 ns         2.62 ns    267853824 bytes_per_second=2.84855T/s
+BM_format_string<wchar_t>/4096          2.57 ns         2.57 ns    272265216 bytes_per_second=5.79715T/s
+BM_format_string<wchar_t>/8192          2.56 ns         2.56 ns    273612800 bytes_per_second=11.6526T/s
+BM_format_string<wchar_t>/16384         2.55 ns         2.55 ns    273793024 bytes_per_second=23.3424T/s
+BM_format_string<wchar_t>/32768         2.59 ns         2.59 ns    269811712 bytes_per_second=45.9856T/s
+BM_format_string<wchar_t>/65536         2.58 ns         2.58 ns    270598144 bytes_per_second=92.2862T/s
+BM_format_string<wchar_t>/131072        2.60 ns         2.60 ns    268828672 bytes_per_second=183.205T/s
+BM_format_string<wchar_t>/262144        4.58 ns         4.58 ns    153092096 bytes_per_second=208.405T/s
+BM_format_string<wchar_t>/524288        4.78 ns         4.77 ns    146276352 bytes_per_second=399.575T/s
+BM_format_string<wchar_t>/1048576       4.57 ns         4.57 ns    154140672 bytes_per_second=835.334T/s

libcxx/before/format_to.txt

+--------------------------------------------------------------------------------------------------------------------------
+Benchmark                                                                Time             CPU   Iterations UserCounters...
+--------------------------------------------------------------------------------------------------------------------------
+BM_format_to_string_back_inserter<std::string>/1                      39.3 ns         39.3 ns     17851007 bytes_per_second=24.2472M/s
+BM_format_to_string_back_inserter<std::string>/2                      40.9 ns         40.9 ns     17113192 bytes_per_second=46.65M/s
+BM_format_to_string_back_inserter<std::string>/4                      45.3 ns         45.2 ns     15429842 bytes_per_second=84.3045M/s
+BM_format_to_string_back_inserter<std::string>/8                      53.4 ns         53.4 ns     13143143 bytes_per_second=142.981M/s
+BM_format_to_string_back_inserter<std::string>/16                     69.8 ns         69.7 ns     10030085 bytes_per_second=218.793M/s
+BM_format_to_string_back_inserter<std::string>/32                      122 ns          122 ns      5743765 bytes_per_second=250.638M/s
+BM_format_to_string_back_inserter<std::string>/64                      206 ns          206 ns      3392054 bytes_per_second=296.04M/s
+BM_format_to_string_back_inserter<std::string>/128                     350 ns          350 ns      1996850 bytes_per_second=348.452M/s
+BM_format_to_string_back_inserter<std::string>/256                     634 ns          634 ns      1097759 bytes_per_second=385.042M/s
+BM_format_to_string_back_inserter<std::string>/512                    1242 ns         1241 ns       563382 bytes_per_second=393.314M/s
+BM_format_to_string_back_inserter<std::string>/1024                   2486 ns         2486 ns       281367 bytes_per_second=392.891M/s
+BM_format_to_string_back_inserter<std::string>/2048                   4883 ns         4881 ns       143466 bytes_per_second=400.146M/s
+BM_format_to_string_back_inserter<std::string>/4096                   9584 ns         9580 ns        72837 bytes_per_second=407.751M/s
+BM_format_to_string_back_inserter<std::string>/8192                  18957 ns        18950 ns        36926 bytes_per_second=412.277M/s
+BM_format_to_string_back_inserter<std::string>/16384                 37743 ns        37729 ns        18557 bytes_per_second=414.141M/s
+BM_format_to_string_back_inserter<std::string>/32768                 75504 ns        75477 ns         9276 bytes_per_second=414.031M/s
+BM_format_to_string_back_inserter<std::string>/65536                149335 ns       149269 ns         4691 bytes_per_second=418.706M/s
+BM_format_to_string_back_inserter<std::string>/131072               325041 ns       324909 ns         2156 bytes_per_second=384.724M/s
+BM_format_to_string_back_inserter<std::string>/262144               695653 ns       695282 ns         1008 bytes_per_second=359.566M/s
+BM_format_to_string_back_inserter<std::string>/524288              1436307 ns      1435605 ns          488 bytes_per_second=348.285M/s
+BM_format_to_string_back_inserter<std::string>/1048576             2938109 ns      2936439 ns          238 bytes_per_second=340.549M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1                52.8 ns         52.8 ns     13273130 bytes_per_second=18.0772M/s
+BM_format_to_string_back_inserter<std::vector<char>>/2                55.1 ns         55.1 ns     12682916 bytes_per_second=34.6119M/s
+BM_format_to_string_back_inserter<std::vector<char>>/4                58.0 ns         58.0 ns     12080785 bytes_per_second=65.8229M/s
+BM_format_to_string_back_inserter<std::vector<char>>/8                66.0 ns         66.0 ns     10599616 bytes_per_second=115.577M/s
+BM_format_to_string_back_inserter<std::vector<char>>/16               83.0 ns         83.0 ns      8450004 bytes_per_second=183.929M/s
+BM_format_to_string_back_inserter<std::vector<char>>/32                118 ns          118 ns      5941561 bytes_per_second=259.193M/s
+BM_format_to_string_back_inserter<std::vector<char>>/64                202 ns          202 ns      3477164 bytes_per_second=302.629M/s
+BM_format_to_string_back_inserter<std::vector<char>>/128               366 ns          366 ns      1915599 bytes_per_second=333.779M/s
+BM_format_to_string_back_inserter<std::vector<char>>/256               637 ns          637 ns      1084507 bytes_per_second=383.511M/s
+BM_format_to_string_back_inserter<std::vector<char>>/512              1219 ns         1219 ns       574962 bytes_per_second=400.551M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1024             2401 ns         2400 ns       292059 bytes_per_second=406.918M/s
+BM_format_to_string_back_inserter<std::vector<char>>/2048             4805 ns         4802 ns       145582 bytes_per_second=406.69M/s
+BM_format_to_string_back_inserter<std::vector<char>>/4096             9464 ns         9461 ns        74002 bytes_per_second=412.872M/s
+BM_format_to_string_back_inserter<std::vector<char>>/8192            18794 ns        18786 ns        37294 bytes_per_second=415.872M/s
+BM_format_to_string_back_inserter<std::vector<char>>/16384           37371 ns        37356 ns        18717 bytes_per_second=418.268M/s
+BM_format_to_string_back_inserter<std::vector<char>>/32768           74969 ns        74942 ns         9335 bytes_per_second=416.99M/s
+BM_format_to_string_back_inserter<std::vector<char>>/65536          148077 ns       148020 ns         4725 bytes_per_second=422.24M/s
+BM_format_to_string_back_inserter<std::vector<char>>/131072         298204 ns       298056 ns         2351 bytes_per_second=419.385M/s
+BM_format_to_string_back_inserter<std::vector<char>>/262144         597450 ns       597173 ns         1171 bytes_per_second=418.639M/s
+BM_format_to_string_back_inserter<std::vector<char>>/524288        1192279 ns      1191700 ns          588 bytes_per_second=419.569M/s
+BM_format_to_string_back_inserter<std::vector<char>>/1048576       2394636 ns      2393339 ns          292 bytes_per_second=417.826M/s
+BM_format_to_string_back_inserter<std::list<char>>/1                  52.2 ns         52.2 ns     13358310 bytes_per_second=18.2737M/s
+BM_format_to_string_back_inserter<std::list<char>>/2                  65.6 ns         65.6 ns     10693004 bytes_per_second=29.0974M/s
+BM_format_to_string_back_inserter<std::list<char>>/4                  93.8 ns         93.8 ns      7462495 bytes_per_second=40.6757M/s
+BM_format_to_string_back_inserter<std::list<char>>/8                   161 ns          161 ns      4375165 bytes_per_second=47.512M/s
+BM_format_to_string_back_inserter<std::list<char>>/16                  310 ns          310 ns      2281308 bytes_per_second=49.2962M/s
+BM_format_to_string_back_inserter<std::list<char>>/32                  621 ns          621 ns      1121230 bytes_per_second=49.1445M/s
+BM_format_to_string_back_inserter<std::list<char>>/64                 1228 ns         1228 ns       570470 bytes_per_second=49.6886M/s
+BM_format_to_string_back_inserter<std::list<char>>/128                2410 ns         2410 ns       288460 bytes_per_second=50.6559M/s
+BM_format_to_string_back_inserter<std::list<char>>/256                4787 ns         4787 ns       146122 bytes_per_second=51.0026M/s
+BM_format_to_string_back_inserter<std::list<char>>/512                9558 ns         9558 ns        73114 bytes_per_second=51.086M/s
+BM_format_to_string_back_inserter<std::list<char>>/1024              19235 ns        19235 ns        36354 bytes_per_second=50.7706M/s
+BM_format_to_string_back_inserter<std::list<char>>/2048              38503 ns        38503 ns        18182 bytes_per_second=50.727M/s
+BM_format_to_string_back_inserter<std::list<char>>/4096              77164 ns        77164 ns         9059 bytes_per_second=50.6226M/s
+BM_format_to_string_back_inserter<std::list<char>>/8192             155284 ns       155283 ns         4509 bytes_per_second=50.3112M/s
+BM_format_to_string_back_inserter<std::list<char>>/16384            311444 ns       311439 ns         2248 bytes_per_second=50.1704M/s
+BM_format_to_string_back_inserter<std::list<char>>/32768            623696 ns       623696 ns         1114 bytes_per_second=50.1045M/s
+BM_format_to_string_back_inserter<std::list<char>>/65536           1248241 ns      1248234 ns          558 bytes_per_second=50.0707M/s
+BM_format_to_string_back_inserter<std::list<char>>/131072          2515105 ns      2515077 ns          277 bytes_per_second=49.7003M/s
+BM_format_to_string_back_inserter<std::list<char>>/262144          5223970 ns      5223802 ns          124 bytes_per_second=47.8579M/s
+BM_format_to_string_back_inserter<std::list<char>>/524288         10747614 ns     10722883 ns           61 bytes_per_second=46.6293M/s
+BM_format_to_string_back_inserter<std::list<char>>/1048576        21823410 ns     21771042 ns           30 bytes_per_second=45.9326M/s
+BM_format_to_string_begin<std::string>/1                              31.0 ns         31.0 ns     22605202 bytes_per_second=30.7703M/s
+BM_format_to_string_begin<std::string>/2                              32.2 ns         32.2 ns     21736311 bytes_per_second=59.2341M/s
+BM_format_to_string_begin<std::string>/4                              35.3 ns         35.3 ns     19843208 bytes_per_second=108.032M/s
+BM_format_to_string_begin<std::string>/8                              42.1 ns         42.0 ns     16651659 bytes_per_second=181.53M/s
+BM_format_to_string_begin<std::string>/16                             56.7 ns         56.6 ns     12351581 bytes_per_second=269.477M/s
+BM_format_to_string_begin<std::string>/32                             86.2 ns         86.1 ns      8110325 bytes_per_second=354.332M/s
+BM_format_to_string_begin<std::string>/64                              149 ns          149 ns      4651728 bytes_per_second=409.186M/s
+BM_format_to_string_begin<std::string>/128                             269 ns          268 ns      2601402 bytes_per_second=454.992M/s
+BM_format_to_string_begin<std::string>/256                             552 ns          552 ns      1243850 bytes_per_second=442.463M/s
+BM_format_to_string_begin<std::string>/512                            1109 ns         1108 ns       626649 bytes_per_second=440.802M/s
+BM_format_to_string_begin<std::string>/1024                           1994 ns         1992 ns       351354 bytes_per_second=490.252M/s
+BM_format_to_string_begin<std::string>/2048                           3968 ns         3964 ns       175329 bytes_per_second=492.676M/s
+BM_format_to_string_begin<std::string>/4096                           7561 ns         7554 ns        91139 bytes_per_second=517.144M/s
+BM_format_to_string_begin<std::string>/8192                          14707 ns        14693 ns        47707 bytes_per_second=531.729M/s
+BM_format_to_string_begin<std::string>/16384                         31224 ns        31196 ns        22445 bytes_per_second=500.864M/s
+BM_format_to_string_begin<std::string>/32768                         61175 ns        61113 ns        11428 bytes_per_second=511.349M/s
+BM_format_to_string_begin<std::string>/65536                        126086 ns       125968 ns         5568 bytes_per_second=496.159M/s
+BM_format_to_string_begin<std::string>/131072                       246662 ns       246400 ns         2833 bytes_per_second=507.305M/s
+BM_format_to_string_begin<std::string>/262144                       495877 ns       495361 ns         1414 bytes_per_second=504.682M/s
+BM_format_to_string_begin<std::string>/524288                       987349 ns       986346 ns          710 bytes_per_second=506.921M/s
+BM_format_to_string_begin<std::string>/1048576                     1971895 ns      1969779 ns          356 bytes_per_second=507.671M/s
+BM_format_to_string_begin<std::vector<char>>/1                        30.6 ns         30.6 ns     22927558 bytes_per_second=31.2022M/s
+BM_format_to_string_begin<std::vector<char>>/2                        31.6 ns         31.5 ns     22216023 bytes_per_second=60.5019M/s
+BM_format_to_string_begin<std::vector<char>>/4                        33.6 ns         33.5 ns     20877618 bytes_per_second=113.731M/s
+BM_format_to_string_begin<std::vector<char>>/8                        41.0 ns         40.9 ns     17139230 bytes_per_second=186.445M/s
+BM_format_to_string_begin<std::vector<char>>/16                       56.1 ns         56.0 ns     12478953 bytes_per_second=272.296M/s
+BM_format_to_string_begin<std::vector<char>>/32                       84.5 ns         84.4 ns      8296548 bytes_per_second=361.547M/s
+BM_format_to_string_begin<std::vector<char>>/64                        143 ns          143 ns      4896161 bytes_per_second=425.865M/s
+BM_format_to_string_begin<std::vector<char>>/128                       262 ns          262 ns      2651436 bytes_per_second=465.744M/s
+BM_format_to_string_begin<std::vector<char>>/256                       508 ns          507 ns      1380229 bytes_per_second=481.179M/s
+BM_format_to_string_begin<std::vector<char>>/512                       982 ns          981 ns       712874 bytes_per_second=497.615M/s
+BM_format_to_string_begin<std::vector<char>>/1024                     1937 ns         1935 ns       361916 bytes_per_second=504.676M/s
+BM_format_to_string_begin<std::vector<char>>/2048                     3792 ns         3788 ns       186057 bytes_per_second=515.549M/s
+BM_format_to_string_begin<std::vector<char>>/4096                     7651 ns         7644 ns        93081 bytes_per_second=511.029M/s
+BM_format_to_string_begin<std::vector<char>>/8192                    14846 ns        14832 ns        47340 bytes_per_second=526.738M/s
+BM_format_to_string_begin<std::vector<char>>/16384                   31165 ns        31136 ns        22297 bytes_per_second=501.832M/s
+BM_format_to_string_begin<std::vector<char>>/32768                   60297 ns        60239 ns        11601 bytes_per_second=518.764M/s
+BM_format_to_string_begin<std::vector<char>>/65536                  126439 ns       126312 ns         5528 bytes_per_second=494.806M/s
+BM_format_to_string_begin<std::vector<char>>/131072                 243962 ns       243717 ns         2867 bytes_per_second=512.891M/s
+BM_format_to_string_begin<std::vector<char>>/262144                 488215 ns       487721 ns         1435 bytes_per_second=512.588M/s
+BM_format_to_string_begin<std::vector<char>>/524288                 973884 ns       972939 ns          721 bytes_per_second=513.907M/s
+BM_format_to_string_begin<std::vector<char>>/1048576               1946522 ns      1944561 ns          360 bytes_per_second=514.255M/s
+BM_format_to_string_begin<std::list<char>>/1                          31.6 ns         31.6 ns     22138930 bytes_per_second=30.1688M/s
+BM_format_to_string_begin<std::list<char>>/2                          34.0 ns         34.0 ns     21180048 bytes_per_second=56.115M/s
+BM_format_to_string_begin<std::list<char>>/4                          37.1 ns         37.1 ns     17839136 bytes_per_second=102.957M/s
+BM_format_to_string_begin<std::list<char>>/8                          52.0 ns         51.9 ns     13413072 bytes_per_second=146.896M/s
+BM_format_to_string_begin<std::list<char>>/16                         74.4 ns         74.4 ns      9343827 bytes_per_second=205.146M/s
+BM_format_to_string_begin<std::list<char>>/32                          122 ns          122 ns      5761779 bytes_per_second=250.798M/s
+BM_format_to_string_begin<std::list<char>>/64                          216 ns          216 ns      3240752 bytes_per_second=282.46M/s
+BM_format_to_string_begin<std::list<char>>/128                         408 ns          408 ns      1718931 bytes_per_second=299.24M/s
+BM_format_to_string_begin<std::list<char>>/256                         791 ns          790 ns       887927 bytes_per_second=308.877M/s
+BM_format_to_string_begin<std::list<char>>/512                        1561 ns         1559 ns       449345 bytes_per_second=313.15M/s
+BM_format_to_string_begin<std::list<char>>/1024                       3121 ns         3118 ns       224735 bytes_per_second=313.169M/s
+BM_format_to_string_begin<std::list<char>>/2048                       6198 ns         6192 ns       113155 bytes_per_second=315.44M/s
+BM_format_to_string_begin<std::list<char>>/4096                      12356 ns        12344 ns        56645 bytes_per_second=316.443M/s
+BM_format_to_string_begin<std::list<char>>/8192                      24787 ns        24761 ns        28283 bytes_per_second=315.513M/s
+BM_format_to_string_begin<std::list<char>>/16384                     49362 ns        49313 ns        14217 bytes_per_second=316.853M/s
+BM_format_to_string_begin<std::list<char>>/32768                     98372 ns        98272 ns         7128 bytes_per_second=317.996M/s
+BM_format_to_string_begin<std::list<char>>/65536                    196544 ns       196343 ns         3565 bytes_per_second=318.321M/s
+BM_format_to_string_begin<std::list<char>>/131072                   398933 ns       398350 ns         1759 bytes_per_second=313.794M/s
+BM_format_to_string_begin<std::list<char>>/262144                   921090 ns       918869 ns          756 bytes_per_second=272.074M/s
+BM_format_to_string_begin<std::list<char>>/524288                  2109426 ns      2104321 ns          333 bytes_per_second=237.606M/s
+BM_format_to_string_begin<std::list<char>>/1048576                 4409461 ns      4398739 ns          159 bytes_per_second=227.338M/s
+BM_format_to_string_span<std::span<char>>/1                           31.4 ns         31.4 ns     22313366 bytes_per_second=30.3883M/s
+BM_format_to_string_span<std::span<char>>/2                           32.0 ns         31.9 ns     21935868 bytes_per_second=59.722M/s
+BM_format_to_string_span<std::span<char>>/4                           35.3 ns         35.3 ns     19796705 bytes_per_second=108.033M/s
+BM_format_to_string_span<std::span<char>>/8                           42.3 ns         42.3 ns     16598367 bytes_per_second=180.515M/s
+BM_format_to_string_span<std::span<char>>/16                          56.0 ns         56.0 ns     12475646 bytes_per_second=272.556M/s
+BM_format_to_string_span<std::span<char>>/32                          87.2 ns         87.1 ns      8093149 bytes_per_second=350.406M/s
+BM_format_to_string_span<std::span<char>>/64                           147 ns          147 ns      4733228 bytes_per_second=415.983M/s
+BM_format_to_string_span<std::span<char>>/128                          274 ns          273 ns      2574297 bytes_per_second=446.608M/s
+BM_format_to_string_span<std::span<char>>/256                          504 ns          503 ns      1386007 bytes_per_second=485.283M/s
+BM_format_to_string_span<std::span<char>>/512                          988 ns          987 ns       706055 bytes_per_second=494.829M/s
+BM_format_to_string_span<std::span<char>>/1024                        1943 ns         1941 ns       360969 bytes_per_second=503.163M/s
+BM_format_to_string_span<std::span<char>>/2048                        3953 ns         3950 ns       176833 bytes_per_second=494.473M/s
+BM_format_to_string_span<std::span<char>>/4096                        7796 ns         7789 ns        90264 bytes_per_second=501.51M/s
+BM_format_to_string_span<std::span<char>>/8192                       14707 ns        14694 ns        47628 bytes_per_second=531.669M/s
+BM_format_to_string_span<std::span<char>>/16384                      31272 ns        31242 ns        22396 bytes_per_second=500.12M/s
+BM_format_to_string_span<std::span<char>>/32768                      60835 ns        60779 ns        11537 bytes_per_second=514.159M/s
+BM_format_to_string_span<std::span<char>>/65536                     124283 ns       124163 ns         5635 bytes_per_second=503.372M/s
+BM_format_to_string_span<std::span<char>>/131072                    245324 ns       245077 ns         2856 bytes_per_second=510.045M/s
+BM_format_to_string_span<std::span<char>>/262144                    494089 ns       493569 ns         1418 bytes_per_second=506.515M/s
+BM_format_to_string_span<std::span<char>>/524288                    987521 ns       986530 ns          710 bytes_per_second=506.827M/s
+BM_format_to_string_span<std::span<char>>/1048576                  1972241 ns      1970158 ns          355 bytes_per_second=507.574M/s
+BM_format_to_string_pointer<char*>/1                                  31.1 ns         31.1 ns     22529776 bytes_per_second=30.6867M/s
+BM_format_to_string_pointer<char*>/2                                  32.2 ns         32.1 ns     21768157 bytes_per_second=59.3642M/s
+BM_format_to_string_pointer<char*>/4                                  34.7 ns         34.7 ns     20190453 bytes_per_second=109.936M/s
+BM_format_to_string_pointer<char*>/8                                  40.6 ns         40.6 ns     17298274 bytes_per_second=187.99M/s
+BM_format_to_string_pointer<char*>/16                                 56.4 ns         56.3 ns     12448474 bytes_per_second=270.948M/s
+BM_format_to_string_pointer<char*>/32                                 84.7 ns         84.6 ns      8294748 bytes_per_second=360.639M/s
+BM_format_to_string_pointer<char*>/64                                  147 ns          147 ns      4759736 bytes_per_second=414.764M/s
+BM_format_to_string_pointer<char*>/128                                 288 ns          288 ns      2437952 bytes_per_second=424.24M/s
+BM_format_to_string_pointer<char*>/256                                 576 ns          575 ns      1228502 bytes_per_second=424.524M/s
+BM_format_to_string_pointer<char*>/512                                1125 ns         1124 ns       633244 bytes_per_second=434.467M/s
+BM_format_to_string_pointer<char*>/1024                               1994 ns         1992 ns       351621 bytes_per_second=490.136M/s
+BM_format_to_string_pointer<char*>/2048                               3861 ns         3857 ns       181973 bytes_per_second=506.332M/s
+BM_format_to_string_pointer<char*>/4096                               7865 ns         7858 ns        88927 bytes_per_second=497.132M/s
+BM_format_to_string_pointer<char*>/8192                              14742 ns        14729 ns        47518 bytes_per_second=530.417M/s
+BM_format_to_string_pointer<char*>/16384                             31428 ns        31400 ns        22250 bytes_per_second=497.619M/s
+BM_format_to_string_pointer<char*>/32768                             60942 ns        60882 ns        11500 bytes_per_second=513.287M/s
+BM_format_to_string_pointer<char*>/65536                            123791 ns       123673 ns         5663 bytes_per_second=505.364M/s
+BM_format_to_string_pointer<char*>/131072                           245225 ns       244971 ns         2854 bytes_per_second=510.265M/s
+BM_format_to_string_pointer<char*>/262144                           493878 ns       493386 ns         1419 bytes_per_second=506.702M/s
+BM_format_to_string_pointer<char*>/524288                           987519 ns       986516 ns          710 bytes_per_second=506.834M/s
+BM_format_to_string_pointer<char*>/1048576                         1972722 ns      1970444 ns          355 bytes_per_second=507.5M/s
+BM_format_to_string_back_inserter<std::wstring>/1                     43.1 ns         43.1 ns     16251106 bytes_per_second=88.5922M/s
+BM_format_to_string_back_inserter<std::wstring>/2                     43.5 ns         43.5 ns     16136813 bytes_per_second=175.456M/s
+BM_format_to_string_back_inserter<std::wstring>/4                     47.5 ns         47.5 ns     14724861 bytes_per_second=321.221M/s
+BM_format_to_string_back_inserter<std::wstring>/8                     74.5 ns         74.4 ns      9428063 bytes_per_second=410.267M/s
+BM_format_to_string_back_inserter<std::wstring>/16                    94.1 ns         94.0 ns      7433127 bytes_per_second=649.048M/s
+BM_format_to_string_back_inserter<std::wstring>/32                     131 ns          131 ns      5346982 bytes_per_second=932.888M/s
+BM_format_to_string_back_inserter<std::wstring>/64                     209 ns          209 ns      3357877 bytes_per_second=1.14147G/s
+BM_format_to_string_back_inserter<std::wstring>/128                    397 ns          397 ns      1766181 bytes_per_second=1.20174G/s
+BM_format_to_string_back_inserter<std::wstring>/256                    795 ns          794 ns       882831 bytes_per_second=1.20078G/s
+BM_format_to_string_back_inserter<std::wstring>/512                   1506 ns         1505 ns       465499 bytes_per_second=1.26764G/s
+BM_format_to_string_back_inserter<std::wstring>/1024                  2860 ns         2857 ns       245055 bytes_per_second=1.33498G/s
+BM_format_to_string_back_inserter<std::wstring>/2048                  5534 ns         5529 ns       127002 bytes_per_second=1.37985G/s
+BM_format_to_string_back_inserter<std::wstring>/4096                 10811 ns        10801 ns        64811 bytes_per_second=1.41269G/s
+BM_format_to_string_back_inserter<std::wstring>/8192                 21450 ns        21429 ns        32634 bytes_per_second=1.4241G/s
+BM_format_to_string_back_inserter<std::wstring>/16384                42268 ns        42227 ns        16584 bytes_per_second=1.44541G/s
+BM_format_to_string_back_inserter<std::wstring>/32768                85714 ns        85628 ns         8178 bytes_per_second=1.4256G/s
+BM_format_to_string_back_inserter<std::wstring>/65536               173425 ns       173246 ns         4043 bytes_per_second=1.40922G/s
+BM_format_to_string_back_inserter<std::wstring>/131072              345710 ns       345372 ns         2026 bytes_per_second=1.41378G/s
+BM_format_to_string_back_inserter<std::wstring>/262144             1199022 ns      1197284 ns          583 bytes_per_second=835.224M/s
+BM_format_to_string_back_inserter<std::wstring>/524288             2504500 ns      2498739 ns          280 bytes_per_second=800.404M/s
+BM_format_to_string_back_inserter<std::wstring>/1048576            4764132 ns      4752655 ns          147 bytes_per_second=841.635M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1             59.8 ns         59.8 ns     11728742 bytes_per_second=63.8387M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/2             60.0 ns         59.9 ns     11677234 bytes_per_second=127.293M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/4             63.8 ns         63.8 ns     11003241 bytes_per_second=239.327M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/8             71.2 ns         71.1 ns      9851596 bytes_per_second=429.149M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/16            86.2 ns         86.1 ns      8177162 bytes_per_second=708.684M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/32             135 ns          135 ns      5193171 bytes_per_second=905.14M/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/64             202 ns          202 ns      3463904 bytes_per_second=1.17977G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/128            376 ns          376 ns      1867466 bytes_per_second=1.26874G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/256            715 ns          714 ns       980020 bytes_per_second=1.3354G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/512           1432 ns         1431 ns       489179 bytes_per_second=1.33331G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1024          2733 ns         2731 ns       256117 bytes_per_second=1.39707G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/2048          5313 ns         5308 ns       131792 bytes_per_second=1.43739G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/4096         10484 ns        10473 ns        66711 bytes_per_second=1.4569G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/8192         21181 ns        21161 ns        33086 bytes_per_second=1.44216G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/16384        41222 ns        41183 ns        16988 bytes_per_second=1.48206G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/32768        83850 ns        83761 ns         8354 bytes_per_second=1.45737G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/65536       169845 ns       169677 ns         4125 bytes_per_second=1.43885G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/131072      339042 ns       338702 ns         2064 bytes_per_second=1.44163G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/262144      679147 ns       678442 ns         1030 bytes_per_second=1.43942G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/524288     1360221 ns      1357530 ns          515 bytes_per_second=1.43873G/s
+BM_format_to_string_back_inserter<std::vector<wchar_t>>/1048576    2928774 ns      2922055 ns          239 bytes_per_second=1.33682G/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1               53.8 ns         53.8 ns     13034245 bytes_per_second=70.9359M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/2               67.7 ns         67.7 ns     10333096 bytes_per_second=112.741M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/4               99.9 ns         99.8 ns      6997013 bytes_per_second=152.851M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/8                169 ns          169 ns      4147214 bytes_per_second=180.516M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/16               320 ns          320 ns      2189621 bytes_per_second=190.983M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/32               643 ns          642 ns      1082037 bytes_per_second=190.06M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/64              1259 ns         1258 ns       556421 bytes_per_second=194.088M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/128             2458 ns         2456 ns       284859 bytes_per_second=198.802M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/256             4867 ns         4863 ns       143991 bytes_per_second=200.818M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/512             9722 ns         9713 ns        72082 bytes_per_second=201.087M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1024           19454 ns        19436 ns        36047 bytes_per_second=200.982M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/2048           38952 ns        38914 ns        17985 bytes_per_second=200.763M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/4096           78010 ns        77931 ns         8980 bytes_per_second=200.498M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/8192          156838 ns       156677 ns         4464 bytes_per_second=199.455M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/16384         314229 ns       313895 ns         2229 bytes_per_second=199.111M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/32768         628546 ns       627928 ns         1109 bytes_per_second=199.067M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/65536        1258339 ns      1256896 ns          555 bytes_per_second=198.903M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/131072       2529588 ns      2525572 ns          276 bytes_per_second=197.975M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/262144       5175627 ns      5163829 ns          125 bytes_per_second=193.655M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/524288      10513129 ns     10488184 ns           62 bytes_per_second=190.691M/s
+BM_format_to_string_back_inserter<std::list<wchar_t>>/1048576     21339631 ns     21291917 ns           31 bytes_per_second=187.865M/s
+BM_format_to_string_begin<std::wstring>/1                             31.7 ns         31.7 ns     22101018 bytes_per_second=120.427M/s
+BM_format_to_string_begin<std::wstring>/2                             32.5 ns         32.5 ns     21565712 bytes_per_second=234.737M/s
+BM_format_to_string_begin<std::wstring>/4                             35.2 ns         35.1 ns     19942828 bytes_per_second=434.32M/s
+BM_format_to_string_begin<std::wstring>/8                             45.4 ns         45.3 ns     15443050 bytes_per_second=673.368M/s
+BM_format_to_string_begin<std::wstring>/16                            56.2 ns         56.2 ns     12449190 bytes_per_second=1086.59M/s
+BM_format_to_string_begin<std::wstring>/32                            86.3 ns         86.2 ns      8120820 bytes_per_second=1.38233G/s
+BM_format_to_string_begin<std::wstring>/64                             146 ns          146 ns      4774782 bytes_per_second=1.62989G/s
+BM_format_to_string_begin<std::wstring>/128                            262 ns          262 ns      2679623 bytes_per_second=1.82201G/s
+BM_format_to_string_begin<std::wstring>/256                            492 ns          491 ns      1425634 bytes_per_second=1.94113G/s
+BM_format_to_string_begin<std::wstring>/512                            950 ns          949 ns       735063 bytes_per_second=2.00942G/s
+BM_format_to_string_begin<std::wstring>/1024                          1919 ns         1917 ns       364794 bytes_per_second=1.99016G/s
+BM_format_to_string_begin<std::wstring>/2048                          3808 ns         3805 ns       183945 bytes_per_second=2.00524G/s
+BM_format_to_string_begin<std::wstring>/4096                          7697 ns         7690 ns        91107 bytes_per_second=1.98429G/s
+BM_format_to_string_begin<std::wstring>/8192                         15136 ns        15122 ns        46245 bytes_per_second=2.01812G/s
+BM_format_to_string_begin<std::wstring>/16384                        31101 ns        31070 ns        22428 bytes_per_second=1.96442G/s
+BM_format_to_string_begin<std::wstring>/32768                        60877 ns        60813 ns        11465 bytes_per_second=2.0073G/s
+BM_format_to_string_begin<std::wstring>/65536                       124100 ns       123975 ns         5643 bytes_per_second=1.96928G/s
+BM_format_to_string_begin<std::wstring>/131072                      250179 ns       249924 ns         2803 bytes_per_second=1.95372G/s
+BM_format_to_string_begin<std::wstring>/262144                      492394 ns       491914 ns         1423 bytes_per_second=1.98523G/s
+BM_format_to_string_begin<std::wstring>/524288                      980484 ns       979015 ns          716 bytes_per_second=1.99499G/s
+BM_format_to_string_begin<std::wstring>/1048576                    1978730 ns      1974187 ns          355 bytes_per_second=1.97866G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1                     31.6 ns         31.6 ns     22165728 bytes_per_second=120.718M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/2                     32.7 ns         32.7 ns     21420917 bytes_per_second=233.489M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/4                     34.8 ns         34.8 ns     20126552 bytes_per_second=438.258M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/8                     41.5 ns         41.5 ns     16859169 bytes_per_second=735.377M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/16                    55.9 ns         55.8 ns     12517082 bytes_per_second=1092.87M/s
+BM_format_to_string_begin<std::vector<wchar_t>>/32                    85.2 ns         85.1 ns      8223499 bytes_per_second=1.40064G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/64                     147 ns          147 ns      4784264 bytes_per_second=1.62661G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/128                    261 ns          261 ns      2676207 bytes_per_second=1.8254G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/256                    494 ns          494 ns      1418791 bytes_per_second=1.93156G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/512                    958 ns          957 ns       729789 bytes_per_second=1.99258G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1024                  1907 ns         1905 ns       368503 bytes_per_second=2.00202G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/2048                  3799 ns         3796 ns       184676 bytes_per_second=2.00987G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/4096                  7762 ns         7755 ns        90150 bytes_per_second=1.9677G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/8192                 15033 ns        15019 ns        46582 bytes_per_second=2.03197G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/16384                31079 ns        31047 ns        22582 bytes_per_second=1.96586G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/32768                60861 ns        60799 ns        11536 bytes_per_second=2.00775G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/65536               120524 ns       120398 ns         5812 bytes_per_second=2.02779G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/131072              239049 ns       238808 ns         2934 bytes_per_second=2.04466G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/262144              485279 ns       484766 ns         1445 bytes_per_second=2.0145G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/524288              979718 ns       978259 ns          716 bytes_per_second=1.99653G/s
+BM_format_to_string_begin<std::vector<wchar_t>>/1048576            1983644 ns      1979303 ns          353 bytes_per_second=1.97355G/s
+BM_format_to_string_begin<std::list<wchar_t>>/1                       31.7 ns         31.7 ns     22075938 bytes_per_second=120.345M/s
+BM_format_to_string_begin<std::list<wchar_t>>/2                       33.3 ns         33.2 ns     21069229 bytes_per_second=229.587M/s
+BM_format_to_string_begin<std::list<wchar_t>>/4                       39.0 ns         39.0 ns     18026922 bytes_per_second=391.126M/s
+BM_format_to_string_begin<std::list<wchar_t>>/8                       49.1 ns         49.1 ns     14243700 bytes_per_second=622.172M/s
+BM_format_to_string_begin<std::list<wchar_t>>/16                      75.0 ns         74.9 ns      9364875 bytes_per_second=814.448M/s
+BM_format_to_string_begin<std::list<wchar_t>>/32                       123 ns          123 ns      5743996 bytes_per_second=995.025M/s
+BM_format_to_string_begin<std::list<wchar_t>>/64                       216 ns          216 ns      3234505 bytes_per_second=1.10596G/s
+BM_format_to_string_begin<std::list<wchar_t>>/128                      407 ns          406 ns      1722427 bytes_per_second=1.17378G/s
+BM_format_to_string_begin<std::list<wchar_t>>/256                      790 ns          790 ns       886444 bytes_per_second=1.20774G/s
+BM_format_to_string_begin<std::list<wchar_t>>/512                     1575 ns         1573 ns       444778 bytes_per_second=1.2122G/s
+BM_format_to_string_begin<std::list<wchar_t>>/1024                    3120 ns         3117 ns       224702 bytes_per_second=1.22381G/s
+BM_format_to_string_begin<std::list<wchar_t>>/2048                    6182 ns         6176 ns       113449 bytes_per_second=1.23534G/s
+BM_format_to_string_begin<std::list<wchar_t>>/4096                   12337 ns        12324 ns        56789 bytes_per_second=1.23815G/s
+BM_format_to_string_begin<std::list<wchar_t>>/8192                   24729 ns        24705 ns        28286 bytes_per_second=1.23528G/s
+BM_format_to_string_begin<std::list<wchar_t>>/16384                  49348 ns        49296 ns        14205 bytes_per_second=1.23814G/s
+BM_format_to_string_begin<std::list<wchar_t>>/32768                  98360 ns        98262 ns         7126 bytes_per_second=1.24229G/s
+BM_format_to_string_begin<std::list<wchar_t>>/65536                 196552 ns       196347 ns         3561 bytes_per_second=1.24341G/s
+BM_format_to_string_begin<std::list<wchar_t>>/131072                393625 ns       393059 ns         1764 bytes_per_second=1.24226G/s
+BM_format_to_string_begin<std::list<wchar_t>>/262144                951326 ns       949033 ns          737 bytes_per_second=1053.7M/s
+BM_format_to_string_begin<std::list<wchar_t>>/524288               2194016 ns      2188643 ns          318 bytes_per_second=913.808M/s
+BM_format_to_string_begin<std::list<wchar_t>>/1048576              4579232 ns      4567819 ns          153 bytes_per_second=875.692M/s
+BM_format_to_string_span<std::span<wchar_t>>/1                        31.6 ns         31.5 ns     22204929 bytes_per_second=120.953M/s
+BM_format_to_string_span<std::span<wchar_t>>/2                        32.7 ns         32.7 ns     21399295 bytes_per_second=233.259M/s
+BM_format_to_string_span<std::span<wchar_t>>/4                        36.7 ns         36.7 ns     19088282 bytes_per_second=415.768M/s
+BM_format_to_string_span<std::span<wchar_t>>/8                        43.7 ns         43.6 ns     15979287 bytes_per_second=699.614M/s
+BM_format_to_string_span<std::span<wchar_t>>/16                       56.0 ns         55.9 ns     12496860 bytes_per_second=1091.73M/s
+BM_format_to_string_span<std::span<wchar_t>>/32                       85.4 ns         85.3 ns      8225066 bytes_per_second=1.39787G/s
+BM_format_to_string_span<std::span<wchar_t>>/64                        148 ns          148 ns      4740781 bytes_per_second=1.61636G/s
+BM_format_to_string_span<std::span<wchar_t>>/128                       261 ns          261 ns      2682991 bytes_per_second=1.82714G/s
+BM_format_to_string_span<std::span<wchar_t>>/256                       491 ns          491 ns      1430130 bytes_per_second=1.94299G/s
+BM_format_to_string_span<std::span<wchar_t>>/512                       963 ns          962 ns       732489 bytes_per_second=1.98347G/s
+BM_format_to_string_span<std::span<wchar_t>>/1024                     1901 ns         1899 ns       367262 bytes_per_second=2.00833G/s
+BM_format_to_string_span<std::span<wchar_t>>/2048                     3818 ns         3814 ns       183916 bytes_per_second=2.00029G/s
+BM_format_to_string_span<std::span<wchar_t>>/4096                     7713 ns         7707 ns        90763 bytes_per_second=1.97998G/s
+BM_format_to_string_span<std::span<wchar_t>>/8192                    15156 ns        15141 ns        46060 bytes_per_second=2.01552G/s
+BM_format_to_string_span<std::span<wchar_t>>/16384                   31055 ns        31024 ns        22591 bytes_per_second=1.96735G/s
+BM_format_to_string_span<std::span<wchar_t>>/32768                   60808 ns        60748 ns        11510 bytes_per_second=2.00944G/s
+BM_format_to_string_span<std::span<wchar_t>>/65536                  123959 ns       123828 ns         5660 bytes_per_second=1.97161G/s
+BM_format_to_string_span<std::span<wchar_t>>/131072                 250169 ns       249924 ns         2804 bytes_per_second=1.95372G/s
+BM_format_to_string_span<std::span<wchar_t>>/262144                 492444 ns       491942 ns         1423 bytes_per_second=1.98512G/s
+BM_format_to_string_span<std::span<wchar_t>>/524288                 979676 ns       978244 ns          716 bytes_per_second=1.99656G/s
+BM_format_to_string_span<std::span<wchar_t>>/1048576               1978049 ns      1973710 ns          355 bytes_per_second=1.97914G/s
+BM_format_to_string_pointer<wchar_t*>/1                               31.2 ns         31.2 ns     22448222 bytes_per_second=122.24M/s
+BM_format_to_string_pointer<wchar_t*>/2                               32.1 ns         32.0 ns     21851431 bytes_per_second=238.191M/s
+BM_format_to_string_pointer<wchar_t*>/4                               34.7 ns         34.6 ns     20205345 bytes_per_second=440.539M/s
+BM_format_to_string_pointer<wchar_t*>/8                               41.3 ns         41.2 ns     16965431 bytes_per_second=740.146M/s
+BM_format_to_string_pointer<wchar_t*>/16                              55.5 ns         55.5 ns     12631410 bytes_per_second=1099.93M/s
+BM_format_to_string_pointer<wchar_t*>/32                              85.6 ns         85.6 ns      8187720 bytes_per_second=1.39314G/s
+BM_format_to_string_pointer<wchar_t*>/64                               146 ns          146 ns      4802464 bytes_per_second=1.63435G/s
+BM_format_to_string_pointer<wchar_t*>/128                              260 ns          260 ns      2691270 bytes_per_second=1.83292G/s
+BM_format_to_string_pointer<wchar_t*>/256                              493 ns          493 ns      1419227 bytes_per_second=1.93562G/s
+BM_format_to_string_pointer<wchar_t*>/512                              953 ns          952 ns       734100 bytes_per_second=2.00283G/s
+BM_format_to_string_pointer<wchar_t*>/1024                            1920 ns         1918 ns       364645 bytes_per_second=1.98838G/s
+BM_format_to_string_pointer<wchar_t*>/2048                            3824 ns         3821 ns       183426 bytes_per_second=1.99692G/s
+BM_format_to_string_pointer<wchar_t*>/4096                            7715 ns         7708 ns        90687 bytes_per_second=1.97968G/s
+BM_format_to_string_pointer<wchar_t*>/8192                           15067 ns        15052 ns        46427 bytes_per_second=2.02746G/s
+BM_format_to_string_pointer<wchar_t*>/16384                          31013 ns        30983 ns        22494 bytes_per_second=1.96996G/s
+BM_format_to_string_pointer<wchar_t*>/32768                          60877 ns        60811 ns        11513 bytes_per_second=2.00736G/s
+BM_format_to_string_pointer<wchar_t*>/65536                         120748 ns       120631 ns         5802 bytes_per_second=2.02387G/s
+BM_format_to_string_pointer<wchar_t*>/131072                        240422 ns       240179 ns         2916 bytes_per_second=2.03299G/s
+BM_format_to_string_pointer<wchar_t*>/262144                        485640 ns       485150 ns         1444 bytes_per_second=2.01291G/s
+BM_format_to_string_pointer<wchar_t*>/524288                        977713 ns       976351 ns          717 bytes_per_second=2.00043G/s
+BM_format_to_string_pointer<wchar_t*>/1048576                      1981062 ns      1976435 ns          354 bytes_per_second=1.97641G/s

libcxx/before/format_to_n.txt

+----------------------------------------------------------------------------------------------------------------------------
+Benchmark                                                                  Time             CPU   Iterations UserCounters...
+----------------------------------------------------------------------------------------------------------------------------
+BM_format_to_n_string_back_inserter<std::string>/1                      41.4 ns         41.4 ns     16852820 bytes_per_second=23.0466M/s
+BM_format_to_n_string_back_inserter<std::string>/2                      45.1 ns         45.1 ns     15529110 bytes_per_second=42.3239M/s
+BM_format_to_n_string_back_inserter<std::string>/4                      53.2 ns         53.2 ns     13173165 bytes_per_second=71.7401M/s
+BM_format_to_n_string_back_inserter<std::string>/8                      68.4 ns         68.4 ns     10252852 bytes_per_second=111.493M/s
+BM_format_to_n_string_back_inserter<std::string>/16                      101 ns          101 ns      6910182 bytes_per_second=151.24M/s
+BM_format_to_n_string_back_inserter<std::string>/32                      207 ns          207 ns      3378133 bytes_per_second=147.417M/s
+BM_format_to_n_string_back_inserter<std::string>/64                      331 ns          331 ns      2116277 bytes_per_second=184.456M/s
+BM_format_to_n_string_back_inserter<std::string>/128                     579 ns          579 ns      1209234 bytes_per_second=210.813M/s
+BM_format_to_n_string_back_inserter<std::string>/256                    1111 ns         1111 ns       631282 bytes_per_second=219.701M/s
+BM_format_to_n_string_back_inserter<std::string>/512                    2232 ns         2232 ns       313589 bytes_per_second=218.791M/s
+BM_format_to_n_string_back_inserter<std::string>/1024                   4367 ns         4367 ns       160232 bytes_per_second=223.637M/s
+BM_format_to_n_string_back_inserter<std::string>/2048                   8586 ns         8586 ns        81465 bytes_per_second=227.484M/s
+BM_format_to_n_string_back_inserter<std::string>/4096                  16994 ns        16994 ns        41206 bytes_per_second=229.863M/s
+BM_format_to_n_string_back_inserter<std::string>/8192                  35051 ns        35051 ns        19976 bytes_per_second=222.889M/s
+BM_format_to_n_string_back_inserter<std::string>/16384                 69720 ns        69720 ns        10020 bytes_per_second=224.11M/s
+BM_format_to_n_string_back_inserter<std::string>/32768                139705 ns       139706 ns         5013 bytes_per_second=223.684M/s
+BM_format_to_n_string_back_inserter<std::string>/65536                278657 ns       278659 ns         2514 bytes_per_second=224.288M/s
+BM_format_to_n_string_back_inserter<std::string>/131072               557540 ns       557541 ns         1250 bytes_per_second=224.199M/s
+BM_format_to_n_string_back_inserter<std::string>/262144              1118672 ns      1118672 ns          624 bytes_per_second=223.479M/s
+BM_format_to_n_string_back_inserter<std::string>/524288              2235741 ns      2235753 ns          313 bytes_per_second=223.638M/s
+BM_format_to_n_string_back_inserter<std::string>/1048576             4489119 ns      4489111 ns          156 bytes_per_second=222.761M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1                57.1 ns         57.1 ns     12270699 bytes_per_second=16.7079M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/2                60.1 ns         60.1 ns     11649114 bytes_per_second=31.7234M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/4                68.3 ns         68.3 ns     10257027 bytes_per_second=55.8682M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/8                85.2 ns         85.2 ns      8169446 bytes_per_second=89.5482M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/16                118 ns          118 ns      5937279 bytes_per_second=129.41M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/32                207 ns          207 ns      3377186 bytes_per_second=147.1M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/64                340 ns          340 ns      2067578 bytes_per_second=179.639M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/128               606 ns          606 ns      1155174 bytes_per_second=201.449M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/256              1148 ns         1148 ns       609615 bytes_per_second=212.654M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/512              2270 ns         2270 ns       308201 bytes_per_second=215.061M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1024             4498 ns         4498 ns       155726 bytes_per_second=217.122M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/2048             9027 ns         9027 ns        77612 bytes_per_second=216.375M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/4096            17947 ns        17947 ns        39080 bytes_per_second=217.66M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/8192            35693 ns        35693 ns        19608 bytes_per_second=218.878M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/16384           70971 ns        70971 ns         9852 bytes_per_second=220.16M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/32768          141795 ns       141793 ns         4941 bytes_per_second=220.392M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/65536          284207 ns       284206 ns         2457 bytes_per_second=219.911M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/131072         568044 ns       568042 ns         1232 bytes_per_second=220.054M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/262144        1137530 ns      1137530 ns          616 bytes_per_second=219.774M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/524288        2274258 ns      2274253 ns          308 bytes_per_second=219.852M/s
+BM_format_to_n_string_back_inserter<std::vector<char>>/1048576       4559305 ns      4559296 ns          153 bytes_per_second=219.332M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1                  53.0 ns         53.0 ns     13219984 bytes_per_second=18.0065M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/2                  68.8 ns         68.8 ns     10212369 bytes_per_second=27.7353M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/4                   101 ns          101 ns      6904278 bytes_per_second=37.6498M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/8                   180 ns          180 ns      3888049 bytes_per_second=42.3662M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/16                  341 ns          341 ns      2051825 bytes_per_second=44.7451M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/32                  756 ns          756 ns       953258 bytes_per_second=40.3562M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/64                 1396 ns         1396 ns       516488 bytes_per_second=43.7128M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/128                2655 ns         2655 ns       261492 bytes_per_second=45.9845M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/256                5303 ns         5303 ns       131917 bytes_per_second=46.0379M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/512               10448 ns        10448 ns        66978 bytes_per_second=46.7334M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1024              20951 ns        20951 ns        33402 bytes_per_second=46.6122M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/2048              41986 ns        41986 ns        16676 bytes_per_second=46.5186M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/4096              84169 ns        84168 ns         8324 bytes_per_second=46.4099M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/8192             169344 ns       169341 ns         4132 bytes_per_second=46.1347M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/16384            339786 ns       339787 ns         2060 bytes_per_second=45.9847M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/32768            681096 ns       681097 ns         1019 bytes_per_second=45.8818M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/65536           1364083 ns      1364079 ns          511 bytes_per_second=45.8185M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/131072          2741135 ns      2741096 ns          254 bytes_per_second=45.6022M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/262144          5588544 ns      5588336 ns          117 bytes_per_second=44.736M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/524288         11320852 ns     11320181 ns           58 bytes_per_second=44.1689M/s
+BM_format_to_n_string_back_inserter<std::list<char>>/1048576        22977305 ns     22976543 ns           29 bytes_per_second=43.5226M/s
+BM_format_to_n_string_begin<std::string>/1                              32.7 ns         32.7 ns     21403497 bytes_per_second=29.1499M/s
+BM_format_to_n_string_begin<std::string>/2                              34.8 ns         34.8 ns     20104323 bytes_per_second=54.7507M/s
+BM_format_to_n_string_begin<std::string>/4                              40.9 ns         40.9 ns     17109175 bytes_per_second=93.2252M/s
+BM_format_to_n_string_begin<std::string>/8                              55.6 ns         55.6 ns     12566851 bytes_per_second=137.114M/s
+BM_format_to_n_string_begin<std::string>/16                             85.3 ns         85.3 ns      8216693 bytes_per_second=178.983M/s
+BM_format_to_n_string_begin<std::string>/32                              162 ns          162 ns      4326062 bytes_per_second=188.541M/s
+BM_format_to_n_string_begin<std::string>/64                              281 ns          281 ns      2491732 bytes_per_second=217.098M/s
+BM_format_to_n_string_begin<std::string>/128                             519 ns          519 ns      1350158 bytes_per_second=235.087M/s
+BM_format_to_n_string_begin<std::string>/256                             991 ns          991 ns       705450 bytes_per_second=246.347M/s
+BM_format_to_n_string_begin<std::string>/512                            1957 ns         1957 ns       357025 bytes_per_second=249.548M/s
+BM_format_to_n_string_begin<std::string>/1024                           3897 ns         3897 ns       179593 bytes_per_second=250.621M/s
+BM_format_to_n_string_begin<std::string>/2048                           7723 ns         7723 ns        90658 bytes_per_second=252.9M/s
+BM_format_to_n_string_begin<std::string>/4096                          15461 ns        15462 ns        45357 bytes_per_second=252.642M/s
+BM_format_to_n_string_begin<std::string>/8192                          31144 ns        31144 ns        22608 bytes_per_second=250.85M/s
+BM_format_to_n_string_begin<std::string>/16384                         62177 ns        62175 ns        11230 bytes_per_second=251.307M/s
+BM_format_to_n_string_begin<std::string>/32768                        124455 ns       124454 ns         5620 bytes_per_second=251.098M/s
+BM_format_to_n_string_begin<std::string>/65536                        248990 ns       248991 ns         2810 bytes_per_second=251.013M/s
+BM_format_to_n_string_begin<std::string>/131072                       494301 ns       494301 ns         1414 bytes_per_second=252.882M/s
+BM_format_to_n_string_begin<std::string>/262144                       988639 ns       988643 ns          708 bytes_per_second=252.872M/s
+BM_format_to_n_string_begin<std::string>/524288                      1977142 ns      1977150 ns          354 bytes_per_second=252.889M/s
+BM_format_to_n_string_begin<std::string>/1048576                     3957373 ns      3957370 ns          177 bytes_per_second=252.693M/s
+BM_format_to_n_string_begin<std::vector<char>>/1                        32.6 ns         32.6 ns     21449903 bytes_per_second=29.2964M/s
+BM_format_to_n_string_begin<std::vector<char>>/2                        35.3 ns         35.3 ns     19799426 bytes_per_second=53.9596M/s
+BM_format_to_n_string_begin<std::vector<char>>/4                        40.8 ns         40.8 ns     17148186 bytes_per_second=93.3894M/s
+BM_format_to_n_string_begin<std::vector<char>>/8                        55.5 ns         55.5 ns     12582440 bytes_per_second=137.361M/s
+BM_format_to_n_string_begin<std::vector<char>>/16                       85.3 ns         85.3 ns      8197729 bytes_per_second=178.814M/s
+BM_format_to_n_string_begin<std::vector<char>>/32                        163 ns          163 ns      4298996 bytes_per_second=187.063M/s
+BM_format_to_n_string_begin<std::vector<char>>/64                        287 ns          287 ns      2437264 bytes_per_second=212.939M/s
+BM_format_to_n_string_begin<std::vector<char>>/128                       528 ns          528 ns      1331030 bytes_per_second=231.322M/s
+BM_format_to_n_string_begin<std::vector<char>>/256                      1006 ns         1006 ns       697904 bytes_per_second=242.634M/s
+BM_format_to_n_string_begin<std::vector<char>>/512                      2031 ns         2031 ns       345151 bytes_per_second=240.434M/s
+BM_format_to_n_string_begin<std::vector<char>>/1024                     3892 ns         3892 ns       179756 bytes_per_second=250.915M/s
+BM_format_to_n_string_begin<std::vector<char>>/2048                     7696 ns         7696 ns        91018 bytes_per_second=253.772M/s
+BM_format_to_n_string_begin<std::vector<char>>/4096                    15625 ns        15625 ns        44746 bytes_per_second=249.998M/s
+BM_format_to_n_string_begin<std::vector<char>>/8192                    31042 ns        31042 ns        22544 bytes_per_second=251.674M/s
+BM_format_to_n_string_begin<std::vector<char>>/16384                   62186 ns        62187 ns        11257 bytes_per_second=251.26M/s
+BM_format_to_n_string_begin<std::vector<char>>/32768                  124567 ns       124567 ns         5624 bytes_per_second=250.868M/s
+BM_format_to_n_string_begin<std::vector<char>>/65536                  249022 ns       249023 ns         2810 bytes_per_second=250.981M/s
+BM_format_to_n_string_begin<std::vector<char>>/131072                 494717 ns       494720 ns         1416 bytes_per_second=252.668M/s
+BM_format_to_n_string_begin<std::vector<char>>/262144                 988930 ns       988936 ns          708 bytes_per_second=252.797M/s
+BM_format_to_n_string_begin<std::vector<char>>/524288                1978701 ns      1978701 ns          354 bytes_per_second=252.691M/s
+BM_format_to_n_string_begin<std::vector<char>>/1048576               3957093 ns      3957062 ns          177 bytes_per_second=252.713M/s
+BM_format_to_n_string_begin<std::list<char>>/1                          32.7 ns         32.7 ns     21382756 bytes_per_second=29.141M/s
+BM_format_to_n_string_begin<std::list<char>>/2                          35.2 ns         35.2 ns     19862978 bytes_per_second=54.226M/s
+BM_format_to_n_string_begin<std::list<char>>/4                          42.7 ns         42.7 ns     16378066 bytes_per_second=89.3966M/s
+BM_format_to_n_string_begin<std::list<char>>/8                          59.3 ns         59.3 ns     11809804 bytes_per_second=128.761M/s
+BM_format_to_n_string_begin<std::list<char>>/16                         97.2 ns         97.2 ns      7204957 bytes_per_second=156.978M/s
+BM_format_to_n_string_begin<std::list<char>>/32                          182 ns          182 ns      3837829 bytes_per_second=167.545M/s
+BM_format_to_n_string_begin<std::list<char>>/64                          343 ns          343 ns      2041752 bytes_per_second=177.919M/s
+BM_format_to_n_string_begin<std::list<char>>/128                         664 ns          664 ns      1054577 bytes_per_second=183.824M/s
+BM_format_to_n_string_begin<std::list<char>>/256                        1311 ns         1311 ns       533849 bytes_per_second=186.255M/s
+BM_format_to_n_string_begin<std::list<char>>/512                        2612 ns         2612 ns       267922 bytes_per_second=186.926M/s
+BM_format_to_n_string_begin<std::list<char>>/1024                       5284 ns         5284 ns       132752 bytes_per_second=184.813M/s
+BM_format_to_n_string_begin<std::list<char>>/2048                      10538 ns        10538 ns        66505 bytes_per_second=185.346M/s
+BM_format_to_n_string_begin<std::list<char>>/4096                      21037 ns        21037 ns        33256 bytes_per_second=185.687M/s
+BM_format_to_n_string_begin<std::list<char>>/8192                      41964 ns        41964 ns        16684 bytes_per_second=186.17M/s
+BM_format_to_n_string_begin<std::list<char>>/16384                     83718 ns        83718 ns         8353 bytes_per_second=186.638M/s
+BM_format_to_n_string_begin<std::list<char>>/32768                    167280 ns       167280 ns         4187 bytes_per_second=186.812M/s
+BM_format_to_n_string_begin<std::list<char>>/65536                    334884 ns       334885 ns         2092 bytes_per_second=186.631M/s
+BM_format_to_n_string_begin<std::list<char>>/131072                   679986 ns       679980 ns         1027 bytes_per_second=183.829M/s
+BM_format_to_n_string_begin<std::list<char>>/262144                  1472285 ns      1472246 ns          474 bytes_per_second=169.809M/s
+BM_format_to_n_string_begin<std::list<char>>/524288                  3201521 ns      3201454 ns          219 bytes_per_second=156.179M/s
+BM_format_to_n_string_begin<std::list<char>>/1048576                 6582037 ns      6581752 ns          106 bytes_per_second=151.935M/s
+BM_format_to_n_string_span<std::span<char>>/1                           32.7 ns         32.7 ns     21435036 bytes_per_second=29.1829M/s
+BM_format_to_n_string_span<std::span<char>>/2                           35.0 ns         35.0 ns     20013174 bytes_per_second=54.485M/s
+BM_format_to_n_string_span<std::span<char>>/4                           41.3 ns         41.3 ns     16930855 bytes_per_second=92.2774M/s
+BM_format_to_n_string_span<std::span<char>>/8                           55.9 ns         55.9 ns     12519983 bytes_per_second=136.395M/s
+BM_format_to_n_string_span<std::span<char>>/16                          84.2 ns         84.2 ns      8296523 bytes_per_second=181.193M/s
+BM_format_to_n_string_span<std::span<char>>/32                           161 ns          161 ns      4331905 bytes_per_second=189.373M/s
+BM_format_to_n_string_span<std::span<char>>/64                           282 ns          282 ns      2484768 bytes_per_second=216.338M/s
+BM_format_to_n_string_span<std::span<char>>/128                          514 ns          514 ns      1363343 bytes_per_second=237.322M/s
+BM_format_to_n_string_span<std::span<char>>/256                          980 ns          980 ns       715603 bytes_per_second=249.16M/s
+BM_format_to_n_string_span<std::span<char>>/512                         1936 ns         1936 ns       360382 bytes_per_second=252.264M/s
+BM_format_to_n_string_span<std::span<char>>/1024                        3871 ns         3871 ns       180731 bytes_per_second=252.296M/s
+BM_format_to_n_string_span<std::span<char>>/2048                        7745 ns         7745 ns        90506 bytes_per_second=252.191M/s
+BM_format_to_n_string_span<std::span<char>>/4096                       15586 ns        15586 ns        44903 bytes_per_second=250.624M/s
+BM_format_to_n_string_span<std::span<char>>/8192                       31252 ns        31252 ns        22399 bytes_per_second=249.985M/s
+BM_format_to_n_string_span<std::span<char>>/16384                      62243 ns        62243 ns        11247 bytes_per_second=251.031M/s
+BM_format_to_n_string_span<std::span<char>>/32768                     124597 ns       124598 ns         5620 bytes_per_second=250.807M/s
+BM_format_to_n_string_span<std::span<char>>/65536                     249141 ns       249141 ns         2810 bytes_per_second=250.862M/s
+BM_format_to_n_string_span<std::span<char>>/131072                    494807 ns       494801 ns         1416 bytes_per_second=252.627M/s
+BM_format_to_n_string_span<std::span<char>>/262144                    989101 ns       989102 ns          708 bytes_per_second=252.755M/s
+BM_format_to_n_string_span<std::span<char>>/524288                   1977346 ns      1977343 ns          354 bytes_per_second=252.865M/s
+BM_format_to_n_string_span<std::span<char>>/1048576                  3956074 ns      3956044 ns          177 bytes_per_second=252.778M/s
+BM_format_to_n_string_pointer<char*>/1                                  32.8 ns         32.8 ns     21331783 bytes_per_second=29.0665M/s
+BM_format_to_n_string_pointer<char*>/2                                  35.1 ns         35.1 ns     19908566 bytes_per_second=54.2839M/s
+BM_format_to_n_string_pointer<char*>/4                                  44.1 ns         44.1 ns     15856442 bytes_per_second=86.4335M/s
+BM_format_to_n_string_pointer<char*>/8                                  60.8 ns         60.8 ns     11520352 bytes_per_second=125.49M/s
+BM_format_to_n_string_pointer<char*>/16                                 91.6 ns         91.6 ns      7638666 bytes_per_second=166.604M/s
+BM_format_to_n_string_pointer<char*>/32                                  166 ns          166 ns      4211443 bytes_per_second=183.497M/s
+BM_format_to_n_string_pointer<char*>/64                                  292 ns          292 ns      2394764 bytes_per_second=208.768M/s
+BM_format_to_n_string_pointer<char*>/128                                 538 ns          538 ns      1292188 bytes_per_second=227.094M/s
+BM_format_to_n_string_pointer<char*>/256                                1034 ns         1034 ns       677278 bytes_per_second=236.034M/s
+BM_format_to_n_string_pointer<char*>/512                                2025 ns         2025 ns       347500 bytes_per_second=241.09M/s
+BM_format_to_n_string_pointer<char*>/1024                               4006 ns         4006 ns       175228 bytes_per_second=243.789M/s
+BM_format_to_n_string_pointer<char*>/2048                               8081 ns         8081 ns        86500 bytes_per_second=241.7M/s
+BM_format_to_n_string_pointer<char*>/4096                              16020 ns        16020 ns        43707 bytes_per_second=243.83M/s
+BM_format_to_n_string_pointer<char*>/8192                              32717 ns        32718 ns        21389 bytes_per_second=238.787M/s
+BM_format_to_n_string_pointer<char*>/16384                             65726 ns        65727 ns        10644 bytes_per_second=237.727M/s
+BM_format_to_n_string_pointer<char*>/32768                            131404 ns       131404 ns         5325 bytes_per_second=237.816M/s
+BM_format_to_n_string_pointer<char*>/65536                            262769 ns       262771 ns         2660 bytes_per_second=237.85M/s
+BM_format_to_n_string_pointer<char*>/131072                           524361 ns       524363 ns         1334 bytes_per_second=238.385M/s
+BM_format_to_n_string_pointer<char*>/262144                          1048815 ns      1048801 ns          668 bytes_per_second=238.368M/s
+BM_format_to_n_string_pointer<char*>/524288                          2097934 ns      2097936 ns          334 bytes_per_second=238.329M/s
+BM_format_to_n_string_pointer<char*>/1048576                         4195349 ns      4195366 ns          167 bytes_per_second=238.358M/s
+BM_format_to_n_string_back_inserter<std::wstring>/1                     41.0 ns         41.0 ns     17107563 bytes_per_second=93.1008M/s
+BM_format_to_n_string_back_inserter<std::wstring>/2                     44.8 ns         44.8 ns     15615043 bytes_per_second=170.285M/s
+BM_format_to_n_string_back_inserter<std::wstring>/4                     55.5 ns         55.5 ns     12612615 bytes_per_second=274.935M/s
+BM_format_to_n_string_back_inserter<std::wstring>/8                     92.7 ns         92.7 ns      7551227 bytes_per_second=329.217M/s
+BM_format_to_n_string_back_inserter<std::wstring>/16                     129 ns          129 ns      5412604 bytes_per_second=472.041M/s
+BM_format_to_n_string_back_inserter<std::wstring>/32                     209 ns          209 ns      3353721 bytes_per_second=584.62M/s
+BM_format_to_n_string_back_inserter<std::wstring>/64                     348 ns          348 ns      2008530 bytes_per_second=701.129M/s
+BM_format_to_n_string_back_inserter<std::wstring>/128                    665 ns          665 ns      1052509 bytes_per_second=734.11M/s
+BM_format_to_n_string_back_inserter<std::wstring>/256                   1339 ns         1339 ns       522542 bytes_per_second=729.526M/s
+BM_format_to_n_string_back_inserter<std::wstring>/512                   2577 ns         2577 ns       271399 bytes_per_second=757.768M/s
+BM_format_to_n_string_back_inserter<std::wstring>/1024                  4986 ns         4986 ns       140371 bytes_per_second=783.438M/s
+BM_format_to_n_string_back_inserter<std::wstring>/2048                  9788 ns         9788 ns        71481 bytes_per_second=798.175M/s
+BM_format_to_n_string_back_inserter<std::wstring>/4096                 19169 ns        19169 ns        36494 bytes_per_second=815.115M/s
+BM_format_to_n_string_back_inserter<std::wstring>/8192                 38115 ns        38115 ns        18377 bytes_per_second=819.888M/s
+BM_format_to_n_string_back_inserter<std::wstring>/16384                76274 ns        76274 ns         9182 bytes_per_second=819.417M/s
+BM_format_to_n_string_back_inserter<std::wstring>/32768               153130 ns       153131 ns         4569 bytes_per_second=816.293M/s
+BM_format_to_n_string_back_inserter<std::wstring>/65536               307449 ns       307449 ns         2278 bytes_per_second=813.143M/s
+BM_format_to_n_string_back_inserter<std::wstring>/131072              613850 ns       613848 ns         1142 bytes_per_second=814.534M/s
+BM_format_to_n_string_back_inserter<std::wstring>/262144             1239516 ns      1239485 ns          563 bytes_per_second=806.787M/s
+BM_format_to_n_string_back_inserter<std::wstring>/524288             2535430 ns      2535361 ns          275 bytes_per_second=788.842M/s
+BM_format_to_n_string_back_inserter<std::wstring>/1048576            5256875 ns      5256654 ns          129 bytes_per_second=760.94M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1             60.7 ns         60.7 ns     11474514 bytes_per_second=62.7996M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/2             64.1 ns         64.1 ns     10914906 bytes_per_second=118.958M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/4             71.9 ns         71.9 ns      9721997 bytes_per_second=212.153M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/8             86.5 ns         86.5 ns      8091667 bytes_per_second=352.792M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/16             121 ns          121 ns      5836266 bytes_per_second=506.23M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/32             206 ns          206 ns      3398569 bytes_per_second=592.177M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/64             346 ns          346 ns      2022232 bytes_per_second=705.263M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/128            645 ns          645 ns      1085694 bytes_per_second=756.995M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/256           1245 ns         1245 ns       562302 bytes_per_second=784.249M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/512           2498 ns         2498 ns       280341 bytes_per_second=781.926M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1024          4859 ns         4859 ns       143965 bytes_per_second=803.953M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/2048          9630 ns         9630 ns        72570 bytes_per_second=811.26M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/4096         18969 ns        18969 ns        36916 bytes_per_second=823.691M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/8192         37644 ns        37645 ns        18605 bytes_per_second=830.134M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/16384        75622 ns        75622 ns         9250 bytes_per_second=826.48M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/32768       151239 ns       151240 ns         4631 bytes_per_second=826.503M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/65536       303268 ns       303269 ns         2307 bytes_per_second=824.35M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/131072      605410 ns       605412 ns         1154 bytes_per_second=825.883M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/262144     1219852 ns      1219812 ns          574 bytes_per_second=819.798M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/524288     2489744 ns      2489681 ns          281 bytes_per_second=803.316M/s
+BM_format_to_n_string_back_inserter<std::vector<wchar_t>>/1048576    5183302 ns      5183156 ns          131 bytes_per_second=771.731M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1               55.2 ns         55.2 ns     12690929 bytes_per_second=69.123M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/2               73.2 ns         73.2 ns      9580261 bytes_per_second=104.201M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/4                106 ns          106 ns      6628034 bytes_per_second=144.372M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/8                184 ns          184 ns      3798971 bytes_per_second=165.854M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/16               351 ns          351 ns      1992346 bytes_per_second=174.056M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/32               754 ns          754 ns       934387 bytes_per_second=161.801M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/64              1420 ns         1420 ns       500553 bytes_per_second=171.889M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/128             2719 ns         2719 ns       257332 bytes_per_second=179.587M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/256             5414 ns         5414 ns       129422 bytes_per_second=180.388M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/512            10836 ns        10836 ns        64540 bytes_per_second=180.248M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1024           21634 ns        21634 ns        32336 bytes_per_second=180.564M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/2048           43282 ns        43282 ns        16172 bytes_per_second=180.503M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/4096           86968 ns        86969 ns         8047 bytes_per_second=179.662M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/8192          174275 ns       174272 ns         4018 bytes_per_second=179.317M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/16384         348291 ns       348290 ns         2010 bytes_per_second=179.448M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/32768         696565 ns       696561 ns         1002 bytes_per_second=179.453M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/65536        1394055 ns      1394056 ns          500 bytes_per_second=179.333M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/131072       2805343 ns      2805290 ns          249 bytes_per_second=178.235M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/262144       5724342 ns      5724148 ns          117 bytes_per_second=174.698M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/524288      11656091 ns     11655591 ns           56 bytes_per_second=171.591M/s
+BM_format_to_n_string_back_inserter<std::list<wchar_t>>/1048576     23642684 ns     23641336 ns           28 bytes_per_second=169.195M/s
+BM_format_to_n_string_begin<std::wstring>/1                             32.8 ns         32.8 ns     21338659 bytes_per_second=116.184M/s
+BM_format_to_n_string_begin<std::wstring>/2                             35.1 ns         35.1 ns     19962824 bytes_per_second=217.565M/s
+BM_format_to_n_string_begin<std::wstring>/4                             40.7 ns         40.7 ns     17172148 bytes_per_second=374.516M/s
+BM_format_to_n_string_begin<std::wstring>/8                             55.1 ns         55.1 ns     12705656 bytes_per_second=554.174M/s
+BM_format_to_n_string_begin<std::wstring>/16                            84.7 ns         84.6 ns      8280633 bytes_per_second=721.036M/s
+BM_format_to_n_string_begin<std::wstring>/32                             161 ns          161 ns      4349905 bytes_per_second=757.732M/s
+BM_format_to_n_string_begin<std::wstring>/64                             276 ns          276 ns      2534042 bytes_per_second=883.741M/s
+BM_format_to_n_string_begin<std::wstring>/128                            509 ns          509 ns      1372698 bytes_per_second=958.403M/s
+BM_format_to_n_string_begin<std::wstring>/256                            992 ns          992 ns       705178 bytes_per_second=984.068M/s
+BM_format_to_n_string_begin<std::wstring>/512                           1970 ns         1970 ns       353902 bytes_per_second=991.398M/s
+BM_format_to_n_string_begin<std::wstring>/1024                          3918 ns         3918 ns       178739 bytes_per_second=997.034M/s
+BM_format_to_n_string_begin<std::wstring>/2048                          7790 ns         7790 ns        89978 bytes_per_second=1002.87M/s
+BM_format_to_n_string_begin<std::wstring>/4096                         15461 ns        15461 ns        45333 bytes_per_second=1010.6M/s
+BM_format_to_n_string_begin<std::wstring>/8192                         30841 ns        30842 ns        22706 bytes_per_second=1013.24M/s
+BM_format_to_n_string_begin<std::wstring>/16384                        61655 ns        61655 ns        11349 bytes_per_second=1013.7M/s
+BM_format_to_n_string_begin<std::wstring>/32768                       122560 ns       122560 ns         5715 bytes_per_second=1019.91M/s
+BM_format_to_n_string_begin<std::wstring>/65536                       244889 ns       244889 ns         2858 bytes_per_second=1020.87M/s
+BM_format_to_n_string_begin<std::wstring>/131072                      489986 ns       489987 ns         1430 bytes_per_second=1020.43M/s
+BM_format_to_n_string_begin<std::wstring>/262144                      979684 ns       979677 ns          715 bytes_per_second=1020.74M/s
+BM_format_to_n_string_begin<std::wstring>/524288                     1973013 ns      1972959 ns          355 bytes_per_second=1013.71M/s
+BM_format_to_n_string_begin<std::wstring>/1048576                    3981417 ns      3981219 ns          176 bytes_per_second=1004.72M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1                     33.6 ns         33.6 ns     20814767 bytes_per_second=113.436M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/2                     37.3 ns         37.3 ns     18792781 bytes_per_second=204.788M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/4                     43.7 ns         43.7 ns     16065440 bytes_per_second=349.277M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/8                     56.5 ns         56.5 ns     12447278 bytes_per_second=540.494M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/16                    87.4 ns         87.4 ns      8068446 bytes_per_second=698.431M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/32                     169 ns          169 ns      4136408 bytes_per_second=721.795M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/64                     295 ns          295 ns      2360916 bytes_per_second=826.69M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/128                    585 ns          585 ns      1203226 bytes_per_second=834.706M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/256                   1065 ns         1065 ns       656226 bytes_per_second=916.686M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/512                   2090 ns         2090 ns       335029 bytes_per_second=934.487M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1024                  4165 ns         4165 ns       168552 bytes_per_second=937.963M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/2048                  7791 ns         7791 ns        89710 bytes_per_second=1002.77M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/4096                 15460 ns        15460 ns        45105 bytes_per_second=1010.69M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/8192                 30845 ns        30845 ns        22699 bytes_per_second=1013.12M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/16384                61662 ns        61663 ns        11338 bytes_per_second=1013.58M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/32768               122521 ns       122520 ns         5713 bytes_per_second=1020.24M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/65536               244851 ns       244851 ns         2856 bytes_per_second=1021.03M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/131072              489456 ns       489459 ns         1430 bytes_per_second=1021.54M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/262144              979774 ns       979772 ns          715 bytes_per_second=1020.65M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/524288             1972600 ns      1972564 ns          355 bytes_per_second=1013.91M/s
+BM_format_to_n_string_begin<std::vector<wchar_t>>/1048576            3982451 ns      3982319 ns          176 bytes_per_second=1004.44M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1                       32.8 ns         32.8 ns     21328814 bytes_per_second=116.253M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/2                       35.1 ns         35.1 ns     19935750 bytes_per_second=217.66M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/4                       42.2 ns         42.2 ns     16603380 bytes_per_second=361.839M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/8                       58.8 ns         58.8 ns     11915649 bytes_per_second=519.34M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/16                      97.0 ns         97.0 ns      7216079 bytes_per_second=629.051M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/32                       177 ns          177 ns      3963446 bytes_per_second=690.276M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/64                       328 ns          328 ns      2135136 bytes_per_second=744.87M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/128                      635 ns          635 ns      1102681 bytes_per_second=768.996M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/256                     1244 ns         1244 ns       562773 bytes_per_second=785.055M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/512                     2466 ns         2466 ns       284767 bytes_per_second=792.117M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1024                    4959 ns         4959 ns       141098 bytes_per_second=787.657M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/2048                    9874 ns         9874 ns        70903 bytes_per_second=791.181M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/4096                   19814 ns        19814 ns        35334 bytes_per_second=788.589M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/8192                   39612 ns        39612 ns        17677 bytes_per_second=788.898M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/16384                  78980 ns        78980 ns         8858 bytes_per_second=791.338M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/32768                 157840 ns       157840 ns         4434 bytes_per_second=791.941M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/65536                 315607 ns       315608 ns         2218 bytes_per_second=792.122M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/131072                655076 ns       655071 ns         1078 bytes_per_second=763.276M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/262144               1461939 ns      1461908 ns          479 bytes_per_second=684.037M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/524288               3152474 ns      3152326 ns          222 bytes_per_second=634.452M/s
+BM_format_to_n_string_begin<std::list<wchar_t>>/1048576              6414448 ns      6414209 ns          109 bytes_per_second=623.615M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/1                        32.7 ns         32.7 ns     21394006 bytes_per_second=116.536M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/2                        35.0 ns         35.0 ns     20034968 bytes_per_second=218.034M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/4                        40.6 ns         40.6 ns     17235539 bytes_per_second=375.663M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/8                        55.0 ns         55.0 ns     12709128 bytes_per_second=555.106M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/16                       84.4 ns         84.4 ns      8299946 bytes_per_second=722.989M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/32                        162 ns          162 ns      4330267 bytes_per_second=755.132M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/64                        278 ns          278 ns      2526618 bytes_per_second=878.343M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/128                       513 ns          513 ns      1365356 bytes_per_second=951.206M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/256                       986 ns          986 ns       711630 bytes_per_second=990.874M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/512                      1958 ns         1958 ns       356572 bytes_per_second=997.49M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/1024                     3845 ns         3845 ns       182090 bytes_per_second=1016.02M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/2048                     7795 ns         7795 ns        89798 bytes_per_second=1002.2M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/4096                    15446 ns        15446 ns        45347 bytes_per_second=1011.57M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/8192                    30846 ns        30847 ns        22706 bytes_per_second=1013.08M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/16384                   61637 ns        61637 ns        11360 bytes_per_second=1014M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/32768                  122584 ns       122584 ns         5714 bytes_per_second=1019.71M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/65536                  245050 ns       245050 ns         2856 bytes_per_second=1020.2M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/131072                 489752 ns       489754 ns         1429 bytes_per_second=1020.92M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/262144                 979507 ns       979507 ns          715 bytes_per_second=1020.92M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/524288                1972638 ns      1972587 ns          354 bytes_per_second=1013.9M/s
+BM_format_to_n_string_span<std::span<wchar_t>>/1048576               3979849 ns      3979713 ns          176 bytes_per_second=1005.1M/s
+BM_format_to_n_string_pointer<wchar_t*>/1                               32.8 ns         32.8 ns     21374386 bytes_per_second=116.409M/s
+BM_format_to_n_string_pointer<wchar_t*>/2                               35.3 ns         35.3 ns     19840628 bytes_per_second=216.3M/s
+BM_format_to_n_string_pointer<wchar_t*>/4                               40.8 ns         40.8 ns     17156415 bytes_per_second=373.608M/s
+BM_format_to_n_string_pointer<wchar_t*>/8                               55.2 ns         55.2 ns     12711670 bytes_per_second=553.204M/s
+BM_format_to_n_string_pointer<wchar_t*>/16                              84.3 ns         84.3 ns      8290762 bytes_per_second=723.8M/s
+BM_format_to_n_string_pointer<wchar_t*>/32                               161 ns          161 ns      4335180 bytes_per_second=756.09M/s
+BM_format_to_n_string_pointer<wchar_t*>/64                               275 ns          275 ns      2540222 bytes_per_second=886.62M/s
+BM_format_to_n_string_pointer<wchar_t*>/128                              508 ns          508 ns      1385500 bytes_per_second=961.218M/s
+BM_format_to_n_string_pointer<wchar_t*>/256                              992 ns          992 ns       705538 bytes_per_second=984.382M/s
+BM_format_to_n_string_pointer<wchar_t*>/512                             1957 ns         1957 ns       358169 bytes_per_second=997.851M/s
+BM_format_to_n_string_pointer<wchar_t*>/1024                            3901 ns         3901 ns       179362 bytes_per_second=1001.45M/s
+BM_format_to_n_string_pointer<wchar_t*>/2048                            7773 ns         7773 ns        90082 bytes_per_second=1005.14M/s
+BM_format_to_n_string_pointer<wchar_t*>/4096                           15470 ns        15470 ns        45319 bytes_per_second=1010.01M/s
+BM_format_to_n_string_pointer<wchar_t*>/8192                           30857 ns        30857 ns        22738 bytes_per_second=1012.74M/s
+BM_format_to_n_string_pointer<wchar_t*>/16384                          61643 ns        61643 ns        11332 bytes_per_second=1013.9M/s
+BM_format_to_n_string_pointer<wchar_t*>/32768                         122561 ns       122562 ns         5714 bytes_per_second=1019.89M/s
+BM_format_to_n_string_pointer<wchar_t*>/65536                         245079 ns       245079 ns         2856 bytes_per_second=1020.08M/s
+BM_format_to_n_string_pointer<wchar_t*>/131072                        489789 ns       489790 ns         1429 bytes_per_second=1020.85M/s
+BM_format_to_n_string_pointer<wchar_t*>/262144                        979134 ns       979131 ns          715 bytes_per_second=1021.31M/s
+BM_format_to_n_string_pointer<wchar_t*>/524288                       1973862 ns      1973786 ns          355 bytes_per_second=1013.28M/s
+BM_format_to_n_string_pointer<wchar_t*>/1048576                      3979557 ns      3979482 ns          176 bytes_per_second=1005.16M/s

libcxx/before/formatted_size.txt

+----------------------------------------------------------------------------------------------------
+Benchmark                                          Time             CPU   Iterations UserCounters...
+----------------------------------------------------------------------------------------------------
+BM_formatted_size_string<char>/1                30.7 ns         30.7 ns     22708628 bytes_per_second=31.0901M/s
+BM_formatted_size_string<char>/2                15.9 ns         15.9 ns     44158114 bytes_per_second=120.323M/s
+BM_formatted_size_string<char>/4                8.36 ns         8.35 ns     83757624 bytes_per_second=456.693M/s
+BM_formatted_size_string<char>/8                5.00 ns         4.99 ns    140042128 bytes_per_second=1.49285G/s
+BM_formatted_size_string<char>/16               3.40 ns         3.40 ns    205922352 bytes_per_second=4.38566G/s
+BM_formatted_size_string<char>/32               2.59 ns         2.59 ns    268813856 bytes_per_second=11.4985G/s
+BM_formatted_size_string<char>/64               2.28 ns         2.28 ns    306919424 bytes_per_second=26.1217G/s
+BM_formatted_size_string<char>/128              2.05 ns         2.05 ns    341980416 bytes_per_second=58.2823G/s
+BM_formatted_size_string<char>/256              1.94 ns         1.94 ns    361398016 bytes_per_second=123.083G/s
+BM_formatted_size_string<char>/512              1.89 ns         1.89 ns    371089408 bytes_per_second=252.395G/s
+BM_formatted_size_string<char>/1024             1.86 ns         1.86 ns    376577024 bytes_per_second=512.856G/s
+BM_formatted_size_string<char>/2048             1.79 ns         1.79 ns    391180288 bytes_per_second=1065.02G/s
+BM_formatted_size_string<char>/4096             1.79 ns         1.79 ns    391004160 bytes_per_second=2.08132T/s
+BM_formatted_size_string<char>/8192             1.79 ns         1.79 ns    392224768 bytes_per_second=4.17236T/s
+BM_formatted_size_string<char>/16384            1.78 ns         1.78 ns    393822208 bytes_per_second=8.38387T/s
+BM_formatted_size_string<char>/32768            1.78 ns         1.78 ns    393740288 bytes_per_second=16.7646T/s
+BM_formatted_size_string<char>/65536            1.78 ns         1.78 ns    392429568 bytes_per_second=33.5266T/s
+BM_formatted_size_string<char>/131072           1.78 ns         1.78 ns    393084928 bytes_per_second=67.0169T/s
+BM_formatted_size_string<char>/262144           1.83 ns         1.83 ns    383254528 bytes_per_second=130.434T/s
+BM_formatted_size_string<char>/524288           1.80 ns         1.80 ns    386400256 bytes_per_second=264.954T/s
+BM_formatted_size_string<char>/1048576          1.81 ns         1.81 ns    385875968 bytes_per_second=528.217T/s
+BM_formatted_size_string<wchar_t>/1             31.2 ns         31.1 ns     22498527 bytes_per_second=122.488M/s
+BM_formatted_size_string<wchar_t>/2             16.1 ns         16.1 ns     43418302 bytes_per_second=473.805M/s
+BM_formatted_size_string<wchar_t>/4             8.55 ns         8.54 ns     81952012 bytes_per_second=1.74505G/s
+BM_formatted_size_string<wchar_t>/8             5.09 ns         5.09 ns    137753792 bytes_per_second=5.85971G/s
+BM_formatted_size_string<wchar_t>/16            3.43 ns         3.42 ns    204534800 bytes_per_second=17.4084G/s
+BM_formatted_size_string<wchar_t>/32            2.60 ns         2.60 ns    269500576 bytes_per_second=45.8081G/s
+BM_formatted_size_string<wchar_t>/64            2.27 ns         2.27 ns    308412352 bytes_per_second=105.006G/s
+BM_formatted_size_string<wchar_t>/128           2.02 ns         2.02 ns    346366976 bytes_per_second=236.043G/s
+BM_formatted_size_string<wchar_t>/256           1.90 ns         1.90 ns    369362176 bytes_per_second=503.073G/s
+BM_formatted_size_string<wchar_t>/512           1.84 ns         1.83 ns    382286848 bytes_per_second=1040.3G/s
+BM_formatted_size_string<wchar_t>/1024          1.80 ns         1.80 ns    388232192 bytes_per_second=2.06773T/s
+BM_formatted_size_string<wchar_t>/2048          1.79 ns         1.79 ns    392097792 bytes_per_second=4.17204T/s
+BM_formatted_size_string<wchar_t>/4096          1.79 ns         1.79 ns    391139328 bytes_per_second=8.32526T/s
+BM_formatted_size_string<wchar_t>/8192          1.79 ns         1.79 ns    391913472 bytes_per_second=16.6698T/s
+BM_formatted_size_string<wchar_t>/16384         1.78 ns         1.78 ns    393592832 bytes_per_second=33.5251T/s
+BM_formatted_size_string<wchar_t>/32768         1.78 ns         1.77 ns    392364032 bytes_per_second=67.194T/s
+BM_formatted_size_string<wchar_t>/65536         1.77 ns         1.77 ns    394985472 bytes_per_second=134.535T/s
+BM_formatted_size_string<wchar_t>/131072        1.77 ns         1.77 ns    394657792 bytes_per_second=269.018T/s
+BM_formatted_size_string<wchar_t>/262144        1.77 ns         1.77 ns    394526720 bytes_per_second=537.963T/s
+BM_formatted_size_string<wchar_t>/524288        1.78 ns         1.78 ns    395313152 bytes_per_second=1072.85T/s
+BM_formatted_size_string<wchar_t>/1048576       1.81 ns         1.80 ns    387973120 bytes_per_second=2.06671P/s

libcxx/include/__format/buffer.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef _LIBCPP___FORMAT_BUFFER_H
 #define _LIBCPP___FORMAT_BUFFER_H
 
+#include <__algorithm/min.h>
 #include <__config>
+#include <__debug>
 #include <__format/formatter.h> // for __char_type TODO FMT Move the concept?
 #include <__iterator/back_insert_iterator.h>
 #include <__iterator/concepts.h>
+#include <__iterator/wrap_iter.h>
+#include <__iterator/iterator_traits.h>
 #include <__utility/move.h>
-#include <array>
 #include <cstddef>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #if _LIBCPP_STD_VER > 17
 
 // TODO FMT Remove this once we require compilers with proper C++20 support.
 // If the compiler has no concepts support, the format header will be disabled.
 // Without concepts support enable_if needs to be used and that too much effort
 // to support compilers with partial C++20 support.
 #if !defined(_LIBCPP_HAS_NO_CONCEPTS)
 
+// TODO FMT move to its own header.
+template <class _OutIt>
+struct _LIBCPP_TEMPLATE_VIS format_to_n_result {
+  _OutIt out;
+  iter_difference_t<_OutIt> size;
+};
+
 namespace __format {
 
-/// The output iterator used for the @ref format_context.
-///
-/// In order to specialize the iterator only for the character type used it
-/// uses a type-erased function pointer to call the underlying buffer storage
-/// function.
 template <__formatter::__char_type _CharT>
-class _LIBCPP_TEMPLATE_VIS __output_iterator {
+class _LIBCPP_TEMPLATE_VIS __output_buffer {
 public:
-  // No Legacy tag since the code isn't available prior to C++20.
-  using value_type = void;
-  using difference_type = ptrdiff_t;
-  using pointer = void;
-  using reference = void;
+  using value_type = _CharT;
 
   template <class _Tp>
-  _LIBCPP_HIDE_FROM_ABI explicit __output_iterator(_Tp* __obj)
-      : __fun_([](_CharT __c, void* __o) { static_cast<_Tp*>(__o)->put(__c); }),
+  _LIBCPP_HIDE_FROM_ABI explicit __output_buffer(_CharT* __ptr,
+                                                 size_t __capacity, _Tp* __obj)
+      : __ptr_(__ptr), __capacity_(__capacity),
+        __flush_([](_CharT* __ptr, size_t __size, void* __o) {
+          static_cast<_Tp*>(__o)->flush(__ptr, __size);
+        }),
         __obj_(__obj) {}
 
-  _LIBCPP_HIDE_FROM_ABI __output_iterator& operator=(_CharT __c) {
-    __fun_(__c, __obj_);
-    return *this;
+  _LIBCPP_HIDE_FROM_ABI void reset(_CharT* __ptr, size_t __capacity) {
+    __ptr_ = __ptr;
+    __capacity_ = __capacity;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI auto make_output_iterator() {
+    return back_insert_iterator{*this};
+  }
+
+  // TODO FMT It would be nice to have an overload to take a
+  // basic_string_view<_CharT> and append directly.
+  _LIBCPP_HIDE_FROM_ABI void push_back(_CharT __c) {
+    __ptr_[__size_++] = __c;
+
+    // Profiling showed flushing after adding is more efficient than flushing
+    // when entering the function.
+    if (__size_ == __capacity_)
+      flush();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI void flush() {
+    __flush_(__ptr_, __size_, __obj_);
+    __size_ = 0;
   }
-  _LIBCPP_HIDE_FROM_ABI __output_iterator& operator*() { return *this; }
-  _LIBCPP_HIDE_FROM_ABI __output_iterator& operator++() { return *this; }
-  _LIBCPP_HIDE_FROM_ABI __output_iterator& operator++(int) { return *this; }
 
 private:
-  void (*__fun_)(_CharT, void*);
+  _CharT* __ptr_;
+  size_t __capacity_;
+  size_t __size_{0};
+  void (*__flush_)(_CharT*, size_t, void*);
   void* __obj_;
 };
 
-/// A "buffer" that directly writes to the supplied iterator.
+/// A storage using an internal buffer.
+///
+/// This storage is used when writing a single element to the output iterator
+/// is expensive.
+template <__formatter::__char_type _CharT>
+class _LIBCPP_TEMPLATE_VIS __internal_storage {
+public:
+  _LIBCPP_HIDE_FROM_ABI _CharT* begin() { return __buffer_; }
+  _LIBCPP_HIDE_FROM_ABI size_t capacity() { return __buffer_size_; }
+
+private:
+  static constexpr size_t __buffer_size_ = 256 / sizeof(_CharT);
+  _CharT __buffer_[__buffer_size_];
+};
+
+/// A storage writing directly to the storage.
 ///
-/// This helper is specialized for all different output iterators used in the
-/// format function. Together with the @ref __output_iterator this offers a
-/// type erasure, reducing the number of formatter specializations.
+/// This requires the storage to be a contiguous buffer of \a _CharT.
+/// Since the output is directly written to the underlaying storage this class
+/// is just an empty class.
+template <__formatter::__char_type _CharT>
+class _LIBCPP_TEMPLATE_VIS __direct_storage {};
+
+template <class _OutIt, class _CharT>
+concept __enable_direct_output = __formatter::__char_type<_CharT> &&
+    (same_as<_OutIt, _CharT*>
+#if _LIBCPP_DEBUG_LEVEL < 2
+     || same_as<_OutIt, __wrap_iter<_CharT*>>
+#endif
+    );
+
+/// Write policy for directly writing to the underlying output.
 template <class _OutIt, __formatter::__char_type _CharT>
-requires(output_iterator<_OutIt, const _CharT&>) class _LIBCPP_TEMPLATE_VIS
-    __iterator_wrapper_buffer {
+class _LIBCPP_TEMPLATE_VIS __writer_direct {
 public:
-  _LIBCPP_HIDE_FROM_ABI explicit __iterator_wrapper_buffer(_OutIt __it)
-      : __it_(_VSTD::move(__it)) {}
+  _LIBCPP_HIDE_FROM_ABI explicit __writer_direct(_OutIt __out_it)
+      : __out_it_(__out_it) {}
 
-  _LIBCPP_HIDE_FROM_ABI void put(_CharT __c) { *__it_++ = __c; }
+  _LIBCPP_HIDE_FROM_ABI auto out() { return __out_it_; }
 
-  _LIBCPP_HIDE_FROM_ABI _OutIt out() { return __it_; }
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT*, size_t __size) {
+    // _OutIt can be a __wrap_iter<CharT*>. Therefore the original iterator
+    // is adjusted.
+    __out_it_ += __size;
+  }
 
 private:
-  _OutIt __it_;
+  _OutIt __out_it_;
+};
+
+/// Write policy for copying the buffer to the output.
+template <class _OutIt, __formatter::__char_type _CharT>
+class _LIBCPP_TEMPLATE_VIS __writer_iterator {
+public:
+  _LIBCPP_HIDE_FROM_ABI explicit __writer_iterator(_OutIt __out_it)
+      : __out_it_{_VSTD::move(__out_it)} {}
+
+  _LIBCPP_HIDE_FROM_ABI auto out() { return __out_it_; }
+
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT* __ptr, size_t __size) {
+    __out_it_ = _VSTD::copy_n(__ptr, __size, _VSTD::move(__out_it_));
+  }
+
+private:
+  _OutIt __out_it_;
 };
 
-/// Concept to see whether a \a _Container is insertable.
-///
-/// The concept is used to validate whether multiple calls to a
-/// \ref back_insert_iterator can be replace by a call to \c _Container::insert.
-///
-/// \note a \a _Container needs to opt-in to the concept by adding a typedef
-/// \ref __enable_format_insertable with the same type as \a _Container.
 template <class _Container>
 concept __insertable =
     same_as<_Container, typename _Container::__enable_format_insertable> &&
     __formatter::__char_type<typename _Container::value_type> &&
     requires(_Container& __t, typename _Container::value_type* __first,
              typename _Container::value_type* __last) {
   __t.insert(__t.end(), __first, __last);
 };
 
 /// Extract the container type of a \ref back_insert_iterator.
 template <class _It>
 struct _LIBCPP_TEMPLATE_VIS __back_insert_iterator_container {
   using type = void;
 };
 
 template <__insertable _Container>
 struct _LIBCPP_TEMPLATE_VIS
     __back_insert_iterator_container<back_insert_iterator<_Container>> {
   using type = _Container;
 };
 
-/// A buffer that wraps a \ref back_insert_iterator for a \a _Container.
+/// Write policy for inserting the buffer in a container.
 template <class _Container>
-class _LIBCPP_TEMPLATE_VIS __container_buffer {
+class _LIBCPP_TEMPLATE_VIS __writer_container {
 public:
   using _CharT = typename _Container::value_type;
 
-  _LIBCPP_HIDE_FROM_ABI explicit __container_buffer(
-      back_insert_iterator<_Container> __it)
-      : __container_(__it.__get_container()) {}
-
-  _LIBCPP_HIDE_FROM_ABI explicit __container_buffer(_Container* __container)
-      : __container_(__container) {}
+  _LIBCPP_HIDE_FROM_ABI explicit __writer_container(
+      back_insert_iterator<_Container> __out_it)
+      : __container_{__out_it.__get_container()} {}
 
-  _LIBCPP_HIDE_FROM_ABI void put(_CharT __c) {
-    *__buffer_it_++ = __c;
-    // Profiling showed flushing after adding is more efficient than flushing
-    // when entering the function.
-    if (__buffer_it_ == __buffer_.end())
-      __flush();
-  }
+  _LIBCPP_HIDE_FROM_ABI auto out() { return back_inserter(*__container_); }
 
-  _LIBCPP_HIDE_FROM_ABI auto out() {
-    __flush();
-    return back_inserter(*__container_);
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT* __ptr, size_t __size) {
+    __container_->insert(__container_->end(), __ptr, __ptr + __size);
   }
 
 private:
-  /// The size of the internal buffer.
-  ///
-  /// Profiling shows a 256 byte buffer seems optimal.
-  /// (256 elements for a char buffer and 64 elements for a 4-byte wchar_t)
-  static constexpr size_t __buffer_size = 256 / sizeof(_CharT);
-
-  array<_CharT, __buffer_size> __buffer_;
-  _CharT* __buffer_it_ = __buffer_.begin();
   _Container* __container_;
-
-  void __flush() {
-    // Use __buffer_it_ instead of end() since the buffer might be partly filled.
-    __container_->insert(__container_->end(), __buffer_.begin(), __buffer_it_);
-    __buffer_it_ = __buffer_.begin();
-  }
 };
 
-/// Selects the type of the buffer for the output iterator.
+/// Selects the type of the writer used for the output iterator.
 template <class _OutIt, class _CharT>
-class _LIBCPP_TEMPLATE_VIS __buffer_selector {
-  using _Iterator = typename __back_insert_iterator_container<_OutIt>::type;
+class _LIBCPP_TEMPLATE_VIS __writer_selector {
+
+  using _Container = typename __back_insert_iterator_container<_OutIt>::type;
+
+public:
+  using type =
+      conditional_t<!same_as<_Container, void>, __writer_container<_Container>,
+                    conditional_t<__enable_direct_output<_OutIt, _CharT>,
+                                  __writer_direct<_OutIt, _CharT>,
+                                  __writer_iterator<_OutIt, _CharT>>>;
+};
+
+/// The generic formatting buffer.
+template <class _OutIt, __formatter::__char_type _CharT>
+requires(output_iterator<_OutIt, const _CharT&>) class _LIBCPP_TEMPLATE_VIS
+    __format_buffer {
+  using _Storage =
+      conditional_t<__enable_direct_output<_OutIt, _CharT>,
+                    __direct_storage<_CharT>, __internal_storage<_CharT>>;
 
 public:
-  using type = conditional_t<same_as<_Iterator, void>,
-                             __iterator_wrapper_buffer<_OutIt, _CharT>,
-                             __container_buffer<_Iterator>>;
+  _LIBCPP_HIDE_FROM_ABI explicit __format_buffer(_OutIt __out_it) requires(
+      same_as<_Storage, __internal_storage<_CharT>>)
+      : __output_(__storage_.begin(), __storage_.capacity(), this),
+        __writer_(_VSTD::move(__out_it)) {}
+
+  _LIBCPP_HIDE_FROM_ABI explicit __format_buffer(_OutIt __out_it) requires(
+      same_as<_Storage, __direct_storage<_CharT>>)
+      : __output_(_VSTD::__unwrap_iter(__out_it), size_t(-1), this),
+        __writer_(_VSTD::move(__out_it)) {}
+
+  _LIBCPP_HIDE_FROM_ABI auto make_output_iterator() {
+    return __output_.make_output_iterator();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT* __ptr, size_t __size) {
+    __writer_.flush(__ptr, __size);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _OutIt out() && {
+    __output_.flush();
+    return _VSTD::move(__writer_).out();
+  }
+
+private:
+  [[no_unique_address]] _Storage __storage_;
+  __output_buffer<_CharT> __output_;
+  typename __writer_selector<_OutIt, _CharT>::type __writer_;
 };
 
 /// A buffer that counts the number of insertions.
 ///
 /// Since \ref formatted_size only needs to know the size the output itself is
 /// discarded.
 template <__formatter::__char_type _CharT>
 class _LIBCPP_TEMPLATE_VIS __formatted_size_buffer {
 public:
-  _LIBCPP_HIDE_FROM_ABI void put(_CharT) { ++__size_; }
+  _LIBCPP_HIDE_FROM_ABI auto make_output_iterator() {
+    return __output_.make_output_iterator();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT*, size_t __size) {
+    __size_ += __size;
+  }
 
-  _LIBCPP_HIDE_FROM_ABI size_t formatted_size() const noexcept {
+  _LIBCPP_HIDE_FROM_ABI size_t result() && {
+    __output_.flush();
     return __size_;
   }
 
 private:
+  __internal_storage<_CharT> __storage_;
+  __output_buffer<_CharT> __output_{__storage_.begin(), __storage_.capacity(),
+                                    this};
   size_t __size_{0};
 };
 
-/// A buffer that counts and limits the number of insertions.
+/// The base of a buffer that counts and limits the number of insertions.
+template <class _OutIt, __formatter::__char_type _CharT, bool>
+requires(output_iterator<_OutIt, const _CharT&>) struct _LIBCPP_TEMPLATE_VIS
+    __format_to_n_buffer_base {
+  using _Size = iter_difference_t<_OutIt>;
+
+public:
+  _LIBCPP_HIDE_FROM_ABI explicit __format_to_n_buffer_base(_OutIt __out_it,
+                                                           _Size __n)
+      : __writer_(_VSTD::move(__out_it)), __n_(__n) {}
+
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT* __ptr, size_t __size) {
+    if (_Size(__size_) <= __n_)
+      __writer_.flush(__ptr, _VSTD::min(_Size(__size), __n_ - __size_));
+    __size_ += __size;
+  }
+
+protected:
+  __internal_storage<_CharT> __storage_;
+  __output_buffer<_CharT> __output_{__storage_.begin(), __storage_.capacity(),
+                                    this};
+  typename __writer_selector<_OutIt, _CharT>::type __writer_;
+
+  _Size __n_;
+  _Size __size_{0};
+};
+
+/// The buffer that counts and limits the number of insertions.
+///
+/// This version is used for direct storage iterators.
 ///
-/// This buffer holds another buffer to do the actual insertions until the
-/// requested maximum has been reached. Once the maximum is reached it only
-/// keeps track of the number of additional insertions.
+/// This limits the size of the "infinite" direct storage buffer so it will
+/// limit the number of writes to the storage.
 template <class _OutIt, __formatter::__char_type _CharT>
 requires(output_iterator<_OutIt, const _CharT&>) class _LIBCPP_TEMPLATE_VIS
-    __format_to_n_buffer {
-  using _Buffer = typename __buffer_selector<_OutIt, _CharT>::type;
+    __format_to_n_buffer_base<_OutIt, _CharT, true> {
   using _Size = iter_difference_t<_OutIt>;
 
 public:
-  _LIBCPP_HIDE_FROM_ABI explicit __format_to_n_buffer(_OutIt __out_it,
+  _LIBCPP_HIDE_FROM_ABI explicit __format_to_n_buffer_base(_OutIt __out_it,
                                                            _Size __n)
-      : __buffer_(_VSTD::move(__out_it)), __n_(__n) {}
-
-  _LIBCPP_HIDE_FROM_ABI void put(_CharT __c) {
-    ++__size_;
-    if (__size_ <= __n_)
-      __buffer_.put(__c);
+      : __output_(_VSTD::__unwrap_iter(__out_it), __n, this),
+        __writer_(_VSTD::move(__out_it)) {
+    _LIBCPP_ASSERT(__n > 0,
+                   "The buffer doesn't work properly with negative sizes. For "
+                   "efficiency the caller is also expected to handle __n == 0");
   }
 
-  _LIBCPP_HIDE_FROM_ABI _OutIt out() { return __buffer_.out(); }
+  _LIBCPP_HIDE_FROM_ABI void flush(_CharT* __ptr, size_t __size) {
+    // A flush on the direct storage buffer happens in two occasions:
+    // - The format function has written n code units. At this point it's no
+    //   longer valid to write to this buffer. So switch to the internal buffer.
+    //   This internal buffer doesn't need to be written anywhere so the flush
+    //   for that buffer does nothing.
+    // - The format_to_n function is finished. In this there's no need to
+    //   switch the buffer, but for simplicity the buffers are still switched.
+    if (__size_ == 0) {
+      __writer_.flush(__ptr, __size);
+      __output_.reset(__storage_.begin(), __storage_.capacity());
+    }
 
-  _LIBCPP_HIDE_FROM_ABI _Size formatted_size() const noexcept {
-    return __size_;
+    __size_ += __size;
   }
 
-private:
-  _Buffer __buffer_;
-  _Size __n_;
+protected:
+  __internal_storage<_CharT> __storage_;
+  __output_buffer<_CharT> __output_;
+  __writer_direct<_OutIt, _CharT> __writer_;
+
   _Size __size_{0};
 };
 
+/// The buffer that counts and limits the number of insertions.
+///
+/// This version is used for non-direct storage iterators.
+template <class _OutIt, __formatter::__char_type _CharT>
+requires(output_iterator<_OutIt, const _CharT&>) struct _LIBCPP_TEMPLATE_VIS
+    __format_to_n_buffer final
+    : public __format_to_n_buffer_base<
+          _OutIt, _CharT, __enable_direct_output<_OutIt, _CharT>> {
+  using _Base =
+      __format_to_n_buffer_base<_OutIt, _CharT,
+                                __enable_direct_output<_OutIt, _CharT>>;
+  using _Size = iter_difference_t<_OutIt>;
+
+public:
+  _LIBCPP_HIDE_FROM_ABI explicit __format_to_n_buffer(_OutIt __out_it,
+                                                      _Size __n)
+      : _Base(_VSTD::move(__out_it), __n) {}
+  _LIBCPP_HIDE_FROM_ABI auto make_output_iterator() {
+    return this->__output_.make_output_iterator();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt> result() && {
+    this->__output_.flush();
+    return {_VSTD::move(this->__writer_).out(), this->__size_};
+  }
+};
+
 } // namespace __format
 
 #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
 #endif //_LIBCPP_STD_VER > 17
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP___FORMAT_BUFFER_H

libcxx/include/__format/format_context.h

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 

 // TODO FMT Implement [format.context]/4
 // [Note 1: For a given type charT, implementations are encouraged to provide a
 // single instantiation of basic_format_context for appending to
 // basic_string<charT>, vector<charT>, or any other container with contiguous
 // storage by wrapping those in temporary objects with a uniform interface
 // (such as a span<charT>) and polymorphic reallocation. - end note]
 
 using format_context =
-    basic_format_context<__format::__output_iterator<char>, char>;
+    basic_format_context<back_insert_iterator<__format::__output_buffer<char>>,
+                         char>;
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-using wformat_context =
-    basic_format_context<__format::__output_iterator<wchar_t>, wchar_t>;
+using wformat_context = basic_format_context<
+    back_insert_iterator<__format::__output_buffer<wchar_t>>, wchar_t>;
 #endif
 
 #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
 
 #endif //_LIBCPP_STD_VER > 17
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // _LIBCPP___FORMAT_FORMAT_CONTEXT_H

libcxx/include/format

__vformat_to(_ParseCtx&& __parse_ctx, _Ctx&& __ctx) {
   }
   return __out_it;
 }
 
 } // namespace __format
 
 template <class _OutIt, class _CharT, class _FormatOutIt>
 requires(output_iterator<_OutIt, const _CharT&>) _LIBCPP_HIDE_FROM_ABI _OutIt
-    __vformat_to_wrapped(
-        _OutIt __out_it, basic_string_view<_CharT> __fmt,
-        basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
-
-  using _Buffer = typename __format::__buffer_selector<_OutIt, _CharT>::type;
-  _Buffer __buffer{_VSTD::move(__out_it)};
-  _VSTD::__format::__vformat_to(
-      basic_format_parse_context{__fmt, __args.__size()},
-      _VSTD::__format_context_create(
-          _VSTD::__format::__output_iterator<_CharT>{
-              _VSTD::addressof(__buffer)},
-          __args));
-  return __buffer.out();
-}
-
-template <class _OutIt, class _CharT, class _FormatOutIt>
-requires(output_iterator<_OutIt, const _CharT&>) _LIBCPP_HIDE_FROM_ABI _OutIt
     __vformat_to(
         _OutIt __out_it, basic_string_view<_CharT> __fmt,
         basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
   if constexpr (same_as<_OutIt, _FormatOutIt>)
     return _VSTD::__format::__vformat_to(
         basic_format_parse_context{__fmt, __args.__size()},
         _VSTD::__format_context_create(_VSTD::move(__out_it), __args));
-  else
-    return _VSTD::__vformat_to_wrapped(_VSTD::move(__out_it), __fmt, __args);
+  else {
+    __format::__format_buffer<_OutIt, _CharT> __buffer{_VSTD::move(__out_it)};
+    _VSTD::__format::__vformat_to(
+        basic_format_parse_context{__fmt, __args.__size()},
+        _VSTD::__format_context_create(__buffer.make_output_iterator(),
+                                       __args));
+    return _VSTD::move(__buffer).out();
+  }
 }
 
 template <output_iterator<const char&> _OutIt>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt
 vformat_to(_OutIt __out_it, string_view __fmt, format_args __args) {
   return _VSTD::__vformat_to(_VSTD::move(__out_it), __fmt, __args);
 }
 

 format_to(_OutIt __out_it, wstring_view __fmt, const _Args&... __args) {
   return _VSTD::vformat_to(_VSTD::move(__out_it), __fmt,
                            _VSTD::make_wformat_args(__args...));
 }
 #endif
 
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
 vformat(string_view __fmt, format_args __args) {
     string __res;
-  using _Buffer = typename __format::__container_buffer<std::string>;
-  _Buffer __buffer{&__res};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<char>{_VSTD::addressof(__buffer)}, __fmt,
-      __args);
-  __buffer.out();
+    _VSTD::vformat_to(back_insert_iterator{__res}, __fmt, __args);
     return __res;
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
 vformat(wstring_view __fmt, wformat_args __args) {
-  using _Buffer = typename __format::__container_buffer<std::wstring>;
     wstring __res;
-  _Buffer __buffer{&__res};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<wchar_t>{_VSTD::addressof(__buffer)}, __fmt,
-      __args);
-  __buffer.out();
+    _VSTD::vformat_to(back_insert_iterator{__res}, __fmt, __args);
     return __res;
 }
 #endif
 
 template <class... _Args>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
 format(string_view __fmt, const _Args&... __args) {
   return _VSTD::vformat(__fmt, _VSTD::make_format_args(__args...));
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <class... _Args>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
 format(wstring_view __fmt, const _Args&... __args) {
   return _VSTD::vformat(__fmt, _VSTD::make_wformat_args(__args...));
 }
 #endif
 
-template <class _OutIt>
-struct _LIBCPP_TEMPLATE_VIS format_to_n_result {
-  _OutIt out;
-  iter_difference_t<_OutIt> size;
-};
+template <class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
+formatted_size(string_view __fmt, const _Args&... __args) {
+  __format::__formatted_size_buffer<char> __buffer;
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), __fmt,
+                      basic_format_args{_VSTD::make_format_args(__args...)});
+
+  return _VSTD::move(__buffer).result();
+}
+
+#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+template <class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
+formatted_size(wstring_view __fmt, const _Args&... __args) {
+  __format::__formatted_size_buffer<wchar_t> __buffer;
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), __fmt,
+                      basic_format_args{_VSTD::make_wformat_args(__args...)});
+
+  return _VSTD::move(__buffer).result();
+}
+#endif
 
 template <output_iterator<const char&> _OutIt, class... _Args>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
 format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, string_view __fmt,
             const _Args&... __args) {
-
-  using _Buffer = __format::__format_to_n_buffer<_OutIt, char>;
-  _Buffer __buffer{_VSTD::move(__out_it), __n};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<char>{_VSTD::addressof(__buffer)}, __fmt,
+  if (__n <= 0) [[unlikely]]
+    return {_VSTD::move(__out_it),
+            iter_difference_t<_OutIt>(formatted_size(__fmt, __args...))};
+
+  __format::__format_to_n_buffer<_OutIt, char> __buffer{_VSTD::move(__out_it),
+                                                        __n};
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), __fmt,
                       basic_format_args{_VSTD::make_format_args(__args...)});
-  return {__buffer.out(), __buffer.formatted_size()};
+  return _VSTD::move(__buffer).result();
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <output_iterator<const wchar_t&> _OutIt, class... _Args>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
 format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, wstring_view __fmt,
             const _Args&... __args) {
-
-  using _Buffer = __format::__format_to_n_buffer<_OutIt, wchar_t>;
-  _Buffer __buffer{_VSTD::move(__out_it), __n};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<wchar_t>{_VSTD::addressof(__buffer)}, __fmt,
-      basic_format_args{_VSTD::make_wformat_args(__args...)});
-  return {__buffer.out(), __buffer.formatted_size()};
-}
-#endif
-
-template <class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
-formatted_size(string_view __fmt, const _Args&... __args) {
-  using _Buffer = __format::__formatted_size_buffer<char>;
-  _Buffer __buffer;
-  _VSTD::__vformat_to(
-      __format::__output_iterator<char>{_VSTD::addressof(__buffer)}, __fmt,
-      basic_format_args{_VSTD::make_format_args(__args...)});
-  return __buffer.formatted_size();
-}
-
-#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-template <class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
-formatted_size(wstring_view __fmt, const _Args&... __args) {
-  using _Buffer = __format::__formatted_size_buffer<wchar_t>;
-  _Buffer __buffer;
-  _VSTD::__vformat_to(
-      __format::__output_iterator<wchar_t>{_VSTD::addressof(__buffer)}, __fmt,
+  if (__n <= 0) [[unlikely]]
+    return {_VSTD::move(__out_it),
+            iter_difference_t<_OutIt>(formatted_size(__fmt, __args...))};
+
+  __format::__format_to_n_buffer<_OutIt, wchar_t> __buffer{
+      _VSTD::move(__out_it), __n};
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), __fmt,
                       basic_format_args{_VSTD::make_wformat_args(__args...)});
-  return __buffer.formatted_size();
+  return _VSTD::move(__buffer).result();
 }
 #endif
 
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
-
-template <class _OutIt, class _CharT, class _FormatOutIt>
-requires(output_iterator<_OutIt, const _CharT&>) _LIBCPP_HIDE_FROM_ABI _OutIt
-    __vformat_to_wrapped(
-        _OutIt __out_it, locale __loc, basic_string_view<_CharT> __fmt,
-        basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
-
-  using _Buffer = typename __format::__buffer_selector<_OutIt, _CharT>::type;
-  _Buffer __buffer{_VSTD::move(__out_it)};
-  _VSTD::__format::__vformat_to(
-      basic_format_parse_context{__fmt, __args.__size()},
-      _VSTD::__format_context_create(
-          _VSTD::__format::__output_iterator<_CharT>{
-              _VSTD::addressof(__buffer)},
-          __args, _VSTD::move(__loc)));
-  return __buffer.out();
-}
-
 template <class _OutIt, class _CharT, class _FormatOutIt>
 requires(output_iterator<_OutIt, const _CharT&>) _LIBCPP_HIDE_FROM_ABI _OutIt
     __vformat_to(
         _OutIt __out_it, locale __loc, basic_string_view<_CharT> __fmt,
         basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
 
   if constexpr (same_as<_OutIt, _FormatOutIt>)
     return _VSTD::__format::__vformat_to(
         basic_format_parse_context{__fmt, __args.__size()},
         _VSTD::__format_context_create(_VSTD::move(__out_it), __args,
                                        _VSTD::move(__loc)));
-  else
-    return _VSTD::__vformat_to_wrapped(_VSTD::move(__out_it),
-                                       _VSTD::move(__loc), __fmt, __args);
+  else {
+    __format::__format_buffer<_OutIt, _CharT> __buffer{_VSTD::move(__out_it)};
+    _VSTD::__format::__vformat_to(
+        basic_format_parse_context{__fmt, __args.__size()},
+        _VSTD::__format_context_create(__buffer.make_output_iterator(),
+                                       __args, _VSTD::move(__loc)));
+    return _VSTD::move(__buffer).out();
+  }
 }
 
 template <output_iterator<const char&> _OutIt>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt vformat_to(
     _OutIt __out_it, locale __loc, string_view __fmt, format_args __args) {
   return _VSTD::__vformat_to(_VSTD::move(__out_it), _VSTD::move(__loc), __fmt,
                              __args);
 }
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt format_to(
     _OutIt __out_it, locale __loc, wstring_view __fmt, const _Args&... __args) {
   return _VSTD::vformat_to(_VSTD::move(__out_it), _VSTD::move(__loc), __fmt,
                            _VSTD::make_wformat_args(__args...));
 }
 #endif
 
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
 vformat(locale __loc, string_view __fmt, format_args __args) {
-  using _Buffer = typename __format::__container_buffer<std::string>;
     string __res;
-  _Buffer __buffer{&__res};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<char>{_VSTD::addressof(__buffer)},
-      _VSTD::move(__loc), __fmt, __args);
-  __buffer.out();
+    _VSTD::vformat_to(back_insert_iterator{__res}, _VSTD::move(__loc), __fmt,
+                      __args);
     return __res;
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
 vformat(locale __loc, wstring_view __fmt, wformat_args __args) {
-  using _Buffer = typename __format::__container_buffer<std::wstring>;
     wstring __res;
-  _Buffer __buffer{&__res};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<wchar_t>{_VSTD::addressof(__buffer)},
-      _VSTD::move(__loc), __fmt, __args);
-  __buffer.out();
+    _VSTD::vformat_to(back_insert_iterator{__res}, _VSTD::move(__loc), __fmt,
+                      __args);
     return __res;
 }
 #endif
 
 template <class... _Args>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
 format(locale __loc, string_view __fmt, const _Args&... __args) {
   return _VSTD::vformat(_VSTD::move(__loc), __fmt,
                         _VSTD::make_format_args(__args...));
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <class... _Args>
 _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
 format(locale __loc, wstring_view __fmt, const _Args&... __args) {
   return _VSTD::vformat(_VSTD::move(__loc), __fmt,
                         _VSTD::make_wformat_args(__args...));
 }
 #endif
 
-template <output_iterator<const char&> _OutIt, class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
-format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc,
-            string_view __fmt, const _Args&... __args) {
-
-  using _Buffer = __format::__format_to_n_buffer<_OutIt, char>;
-  _Buffer __buffer{_VSTD::move(__out_it), __n};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<char>{_VSTD::addressof(__buffer)},
-      _VSTD::move(__loc), __fmt,
+template <class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
+formatted_size(locale __loc, string_view __fmt, const _Args&... __args) {
+  __format::__formatted_size_buffer<char> __buffer;
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), _VSTD::move(__loc),__fmt,
                       basic_format_args{_VSTD::make_format_args(__args...)});
-  return {__buffer.out(), __buffer.formatted_size()};
+  return _VSTD::move(__buffer).result();
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-template <output_iterator<const wchar_t&> _OutIt, class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
-format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc,
-            wstring_view __fmt, const _Args&... __args) {
-
-  using _Buffer = __format::__format_to_n_buffer<_OutIt, wchar_t>;
-  _Buffer __buffer{_VSTD::move(__out_it), __n};
-  _VSTD::__vformat_to(
-      __format::__output_iterator<wchar_t>{_VSTD::addressof(__buffer)},
-      _VSTD::move(__loc), __fmt,
+template <class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
+formatted_size(locale __loc, wstring_view __fmt, const _Args&... __args) {
+  __format::__formatted_size_buffer<wchar_t> __buffer;
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), _VSTD::move(__loc),__fmt,
                       basic_format_args{_VSTD::make_wformat_args(__args...)});
-  return {__buffer.out(), __buffer.formatted_size()};
+
+  return _VSTD::move(__buffer).result();
 }
 #endif
 
-template <class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
-formatted_size(locale __loc, string_view __fmt, const _Args&... __args) {
-  using _Buffer = __format::__formatted_size_buffer<char>;
-  _Buffer __buffer;
-  _VSTD::__vformat_to(
-      __format::__output_iterator<char>{_VSTD::addressof(__buffer)},
-      _VSTD::move(__loc), __fmt,
+template <output_iterator<const char&> _OutIt, class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
+format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc,
+            string_view __fmt, const _Args&... __args) {
+  if (__n <= 0) [[unlikely]]
+    return {_VSTD::move(__out_it),
+            iter_difference_t<_OutIt>(formatted_size(__fmt, __args...))};
+
+  __format::__format_to_n_buffer<_OutIt, char> __buffer{_VSTD::move(__out_it),
+                                                        __n};
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), _VSTD::move(__loc),
+                      __fmt,
                       basic_format_args{_VSTD::make_format_args(__args...)});
-  return __buffer.formatted_size();
+  return _VSTD::move(__buffer).result();
 }
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-template <class... _Args>
-_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
-formatted_size(locale __loc, wstring_view __fmt, const _Args&... __args) {
-  using _Buffer = __format::__formatted_size_buffer<wchar_t>;
-  _Buffer __buffer;
-  _VSTD::__vformat_to(
-      __format::__output_iterator<wchar_t>{_VSTD::addressof(__buffer)},
-      _VSTD::move(__loc), __fmt,
+template <output_iterator<const wchar_t&> _OutIt, class... _Args>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
+format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc,
+            wstring_view __fmt, const _Args&... __args) {
+  if (__n <= 0) [[unlikely]]
+    return {_VSTD::move(__out_it),
+            iter_difference_t<_OutIt>(formatted_size(__fmt, __args...))};
+
+  __format::__format_to_n_buffer<_OutIt, wchar_t> __buffer{
+      _VSTD::move(__out_it), __n};
+  _VSTD::__vformat_to(__buffer.make_output_iterator(), _VSTD::move(__loc),
+                      __fmt,
                       basic_format_args{_VSTD::make_wformat_args(__args...)});
-  return __buffer.formatted_size();
+  return _VSTD::move(__buffer).result();
 }
 #endif
 
 #endif // _LIBCPP_HAS_NO_LOCALIZATION
 
 #endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
 #endif //_LIBCPP_STD_VER > 17
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)
 
 #endif // _LIBCPP_FORMAT

libcxx/test/libcxx/utilities/format/format.formatter/format.context/types.compile.pass.cpp

 //===----------------------------------------------------------------------===//
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
static_assert(
                      std::formatter<std::basic_string_view<CharT>, CharT>>);
   static_assert(
       std::is_same_v<typename std::basic_format_context<
                          OutIt, CharT>::template formatter_type<const void*>,
                      std::formatter<const void*, CharT>>);
 }
 
 constexpr void test() {
-  test<std::__format::__output_iterator<char>, char>();
+  test<std::back_insert_iterator<std::__format::__output_buffer<char>>, char>();
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
-  test<std::__format::__output_iterator<wchar_t>, wchar_t>();
+  test<std::back_insert_iterator<std::__format::__output_buffer<wchar_t>>,
+       wchar_t>();
 #endif
 }
 
 static_assert(
-    std::is_same_v<std::format_context,
-                   std::basic_format_context<
-                       std::__format::__output_iterator<char>, char>>);
+    std::is_same_v<
+        std::format_context,
+            std::back_insert_iterator<std::__format::__output_buffer<char>>,
+            char>>);
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 static_assert(
-    std::is_same_v<std::wformat_context,
-                   std::basic_format_context<
-                       std::__format::__output_iterator<wchar_t>, wchar_t>>);
+    std::is_same_v<
+        std::wformat_context,
+            std::back_insert_iterator< std::__format::__output_buffer<wchar_t>>,
+            wchar_t>>);
 #endif