[libc++] "Implements" new SI prefixis.

[Mordante]

Summary

Like yocto, zepto, zetta, and yotta. The new prefixes quecto, ronto,
ronna, and quetta can't be implemented in a intmax_t. So their
implementation does nothing.

Implements

• P2734R0 Adding the new SI prefixes

Depends on D153192

[Mordante]

Adds updated generated files.

[philnik]

libcxx/include/ratio

43

Otherwise this is really confusing.

[h-vetinari]

libcxx/include/ratio

65

libcxx/docs/Status/Cxx2cPapers.csv

 "`P0792R14 <https://wg21.link/P0792R14>`__","LWG","``function_ref``: a type-erased callable reference","Varna June 2023","","",""
 "`P2874R2 <https://wg21.link/P2874R2>`__","LWG","Mandating Annex D Require No More","Varna June 2023","","",""
 "`P2757R3 <https://wg21.link/P2757R3>`__","LWG","Type-checking format args","Varna June 2023","","","|format|"
 "`P2637R3 <https://wg21.link/P2637R3>`__","LWG","Member ``visit``","Varna June 2023","","","|format|"
 "`P2641R4 <https://wg21.link/P2641R4>`__","CWG, LWG","Checking if a ``union`` alternative is active","Varna June 2023","","",""
 "`P1759R6 <https://wg21.link/P1759R6>`__","LWG","Native handles and file streams","Varna June 2023","","",""
 "`P2697R1 <https://wg21.link/P2697R1>`__","LWG","Interfacing ``bitset`` with ``string_view``","Varna June 2023","","",""
 "`P1383R2 <https://wg21.link/P1383R2>`__","LWG","More ``constexpr`` for ``<cmath>`` and ``<complex>``","Varna June 2023","","",""
-"`P2734R0 <https://wg21.link/P2734R0>`__","LWG","Adding the new SI prefixes","Varna June 2023","","",""
+"`P2734R0 <https://wg21.link/P2734R0>`__","LWG","Adding the new SI prefixes","Varna June 2023","|Complete|","Clang 17",""
 "`P2548R6 <https://wg21.link/P2548R6>`__","LWG","``copyable_function``","Varna June 2023","","",""
 "`P2714R1 <https://wg21.link/P2714R1>`__","LWG","Bind front and back to NTTP callables","Varna June 2023","","",""
 "`P2630R4 <https://wg21.link/P2630R4>`__","LWG","``submdspan``","Varna June 2023","","",""
 "","","","","","",""

libcxx/include/ratio

 template <class R1, class R2> struct ratio_equal;
 template <class R1, class R2> struct ratio_not_equal;
 template <class R1, class R2> struct ratio_less;
 template <class R1, class R2> struct ratio_less_equal;
 template <class R1, class R2> struct ratio_greater;
 template <class R1, class R2> struct ratio_greater_equal;
 
 // convenience SI typedefs
+using quecto = ratio <1 , 1'000'000'000'000'000'000'000'000'000'000>; // Since C++26 not supported
+using ronto = ratio <1 , 1'000'000'000'000'000'000'000'000'000>;      // Since C++26 not supported
 typedef ratio<1, 1000000000000000000000000> yocto;  // not supported
 typedef ratio<1,    1000000000000000000000> zepto;  // not supported
 typedef ratio<1,       1000000000000000000> atto;
 typedef ratio<1,          1000000000000000> femto;
 typedef ratio<1,             1000000000000> pico;
 typedef ratio<1,                1000000000> nano;
 typedef ratio<1,                   1000000> micro;
 typedef ratio<1,                      1000> milli;
 typedef ratio<1,                       100> centi;
 typedef ratio<1,                        10> deci;
 typedef ratio<                       10, 1> deca;
 typedef ratio<                      100, 1> hecto;
 typedef ratio<                     1000, 1> kilo;
 typedef ratio<                  1000000, 1> mega;
 typedef ratio<               1000000000, 1> giga;
 typedef ratio<            1000000000000, 1> tera;
 typedef ratio<         1000000000000000, 1> peta;
 typedef ratio<      1000000000000000000, 1> exa;
 typedef ratio<   1000000000000000000000, 1> zetta;  // not supported
 typedef ratio<1000000000000000000000000, 1> yotta;  // not supported
+using ronna = ratio <1'000'000'000'000'000'000'000'000'000' 1>;      // Since C++26 not supported
+using quetta = ratio <1'000'000'000'000'000'000'000'000'000'000, 1>; // Since C++26 not supported
 
   // 20.11.5, ratio comparison
   template <class R1, class R2> inline constexpr bool ratio_equal_v
     = ratio_equal<R1, R2>::value;                                       // C++17
   template <class R1, class R2> inline constexpr bool ratio_not_equal_v
     = ratio_not_equal<R1, R2>::value;                                   // C++17
   template <class R1, class R2> inline constexpr bool ratio_less_v
     = ratio_less<R1, R2>::value;                                        // C++17

libcxx/utils/generate_feature_test_macro_components.py

for x in [
             "values": {"c++23": 202110},
             "headers": ["ranges", "tuple", "utility"],
             "unimplemented": True,
         },
         {
             "name": "__cpp_lib_ratio",
             "values": {"c++26": 202306}, # P2734R0 Adding the new SI prefixes
             "headers": ["ratio"],
-            "unimplemented": True,
         },
         {
             "name": "__cpp_lib_raw_memory_algorithms",
             "values": {"c++17": 201606},
             "headers": ["memory"],
         },
         {
             "name": "__cpp_lib_rcu",