[libc++] Make the naming of private member variables consistent and enforce it through readability-identifier-naming

[philnik]

@Mordante You are currently working on chrono, right? Is there anything that interferes with one of your patches?

[Mordante]

Thanks for working on this! In general SGTM, but I would like to see the CI pass after rebasing.

In D129386#3639398, @philnik wrote:

@Mordante You are currently working on chrono, right? Is there anything that interferes with one of your patches?

Correct, but only on non-member functions. I don't see any conflicts, thanks for asking.

libcxx/.clang-tidy

46

Not your change but please verify whether https://reviews.llvm.org/D129503#inline-1244548 is addressed otherwise please rebase and fix that before landing this patch.

46

Maybe not this patch but can we add a regex that when a member starts with __ it should end with _.

libcxx/include/__chrono/year.h

105

This will conflict with D129442, sorry I wasn't aware of this patch.

libcxx/include/any

315

This prompted my regex question, since they weren't updated.

[philnik]

• Address comments

libcxx/.clang-tidy

46

I'll try, but that might require a custom clang-tidy check. I think we should first work through the checks already available before adding custom ones for us. It might work with PublicMemberCase combined with PublicMemberIgnoredRegexp though. I'll try that after the easier ones.

libcxx/include/__chrono/year.h

105

I discovered the tautological compare while working on this patch, so I already expected a merge-conflict. It's small enough that I thought it wouldn't matter that much.

libcxx/include/any

315

With this patch I'm only checking private members, since protected or public members could be required by the standard. I'm working on checking more, but it'll take some time to get most things checked.

[philnik]

• Try to fix CI

[philnik]

• Next try

[philnik]

• Rebased
• Try to fix CI

[philnik]

• Fix merge conflict

[philnik]

• Rebased
• Try to fix CI

[philnik]

• Try to fix CI

[ldionne]

LGTM.

I don't think this should break the LLDB pretty-printers since they use indices to access members (so changing the names shouldn't matter).

[aprantl]

FYI, this broke a whole bunch of dataformatters in LLDB.

See https://reviews.llvm.org/D133618

libcxx/.clang-tidy

CheckOptions:
   - key:   readability-function-size.LineThreshold
     value: 194 # TODO: bring that number down
   - key:   readability-identifier-naming.GetConfigPerFile
     value: false
   - key:   readability-identifier-naming.ParameterCase
     value: lower_case
   - key:   readability-identifier-naming.ParameterPrefix
     value: __
+  - key:   readability-identifier-naming.PrivateMemberCase
+    value: lower_case
+  - key:   readability-identifier-naming.PrivateMemberPrefix
+    value: __
+  - key:   readability-identifier-naming.PrivateMemberSuffix
+    value: _
 
 # TODO: investigate these checks
 # bugprone-branch-clone,
 # bugprone-macro-parentheses,
 # cppcoreguidelines-prefer-member-initializer,
 # misc-unused-parameters,
 # modernize-use-bool-literals,
 # modernize-use-default-member-init,

libcxx/include/__algorithm/shuffle.h

 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_TYPE_VIS __libcpp_debug_randomizer {
 public:
   __libcpp_debug_randomizer() {
-    __state = __seed();
-    __inc = __state + 0xda3e39cb94b95bdbULL;
-    __inc = (__inc << 1) | 1;
+    __state_ = __seed();
+    __inc_ = __state_ + 0xda3e39cb94b95bdbULL;
+    __inc_ = (__inc_ << 1) | 1;
   }
   typedef uint_fast32_t result_type;
 
   static const result_type _Min = 0;
   static const result_type _Max = 0xFFFFFFFF;
 
   _LIBCPP_HIDE_FROM_ABI result_type operator()() {
-    uint_fast64_t __oldstate = __state;
-    __state = __oldstate * 6364136223846793005ULL + __inc;
+    uint_fast64_t __oldstate = __state_;
+    __state_ = __oldstate * 6364136223846793005ULL + __inc_;
     return __oldstate >> 32;
   }
 
   static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR result_type min() { return _Min; }
   static _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR result_type max() { return _Max; }
 
 private:
-  uint_fast64_t __state;
-  uint_fast64_t __inc;
+  uint_fast64_t __state_;
+  uint_fast64_t __inc_;
   _LIBCPP_HIDE_FROM_ABI static uint_fast64_t __seed() {
 #ifdef _LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY_SEED
     return _LIBCPP_DEBUG_RANDOMIZE_UNSPECIFIED_STABILITY_SEED;
 #else
     static char __x;
     return reinterpret_cast<uintptr_t>(&__x);
 #endif
   }

libcxx/include/__chrono/day.h

 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class day {
 private:
-    unsigned char __d;
+    unsigned char __d_;
 public:
     _LIBCPP_HIDE_FROM_ABI day() = default;
-    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr day(unsigned __val) noexcept : __d(static_cast<unsigned char>(__val)) {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr day& operator++()    noexcept { ++__d; return *this; }
+    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr day(unsigned __val) noexcept : __d_(static_cast<unsigned char>(__val)) {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr day& operator++()    noexcept { ++__d_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr day  operator++(int) noexcept { day __tmp = *this; ++(*this); return __tmp; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr day& operator--()    noexcept { --__d; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr day& operator--()    noexcept { --__d_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr day  operator--(int) noexcept { day __tmp = *this; --(*this); return __tmp; }
     _LIBCPP_HIDE_FROM_ABI        constexpr day& operator+=(const days& __dd) noexcept;
     _LIBCPP_HIDE_FROM_ABI        constexpr day& operator-=(const days& __dd) noexcept;
-    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr operator unsigned() const noexcept { return __d; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __d >= 1 && __d <= 31; }
+    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr operator unsigned() const noexcept { return __d_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __d_ >= 1 && __d_ <= 31; }
   };
 
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const day& __lhs, const day& __rhs) noexcept
 { return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr

libcxx/include/__chrono/hh_mm_ss.h

 public:
     _LIBCPP_HIDE_FROM_ABI static unsigned constexpr fractional_width = __width(__CommonType::period::den) < 19 ?
                                                  __width(__CommonType::period::den) : 6u;
     using precision = duration<typename __CommonType::rep, ratio<1, __pow10(fractional_width)>>;
 
     _LIBCPP_HIDE_FROM_ABI constexpr hh_mm_ss() noexcept : hh_mm_ss{_Duration::zero()} {}
 
     _LIBCPP_HIDE_FROM_ABI constexpr explicit hh_mm_ss(_Duration __d) noexcept :
-        __is_neg(__d < _Duration(0)),
-        __h(duration_cast<chrono::hours>  (abs(__d))),
-        __m(duration_cast<chrono::minutes>(abs(__d) - hours())),
-        __s(duration_cast<chrono::seconds>(abs(__d) - hours() - minutes())),
-        __f(duration_cast<precision>      (abs(__d) - hours() - minutes() - seconds()))
+        __is_neg_(__d < _Duration(0)),
+        __h_(duration_cast<chrono::hours>  (abs(__d))),
+        __m_(duration_cast<chrono::minutes>(abs(__d) - hours())),
+        __s_(duration_cast<chrono::seconds>(abs(__d) - hours() - minutes())),
+        __f_(duration_cast<precision>      (abs(__d) - hours() - minutes() - seconds()))
         {}
 
-    _LIBCPP_HIDE_FROM_ABI constexpr bool is_negative()        const noexcept { return __is_neg; }
-    _LIBCPP_HIDE_FROM_ABI constexpr chrono::hours hours()     const noexcept { return __h; }
-    _LIBCPP_HIDE_FROM_ABI constexpr chrono::minutes minutes() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI constexpr chrono::seconds seconds() const noexcept { return __s; }
-    _LIBCPP_HIDE_FROM_ABI constexpr precision subseconds()    const noexcept { return __f; }
+    _LIBCPP_HIDE_FROM_ABI constexpr bool is_negative()        const noexcept { return __is_neg_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr chrono::hours hours()     const noexcept { return __h_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr chrono::minutes minutes() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr chrono::seconds seconds() const noexcept { return __s_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr precision subseconds()    const noexcept { return __f_; }
 
     _LIBCPP_HIDE_FROM_ABI constexpr precision to_duration() const noexcept
     {
-        auto __dur = __h + __m + __s + __f;
-        return __is_neg ? -__dur : __dur;
+        auto __dur = __h_ + __m_ + __s_ + __f_;
+        return __is_neg_ ? -__dur : __dur;
     }
 
     _LIBCPP_HIDE_FROM_ABI constexpr explicit operator precision() const noexcept { return to_duration(); }
 
 private:
-    bool            __is_neg;
-    chrono::hours   __h;
-    chrono::minutes __m;
-    chrono::seconds __s;
-    precision       __f;
+    bool            __is_neg_;
+    chrono::hours   __h_;
+    chrono::minutes __m_;
+    chrono::seconds __s_;
+    precision       __f_;
 };
 
 _LIBCPP_HIDE_FROM_ABI constexpr bool is_am(const hours& __h) noexcept { return __h >= hours( 0) && __h < hours(12); }
 _LIBCPP_HIDE_FROM_ABI constexpr bool is_pm(const hours& __h) noexcept { return __h >= hours(12) && __h < hours(24); }
 
 _LIBCPP_HIDE_FROM_ABI constexpr hours make12(const hours& __h) noexcept
 {
     if      (__h == hours( 0)) return hours(12);

libcxx/include/__chrono/month.h

 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class month {
 private:
-    unsigned char __m;
+    unsigned char __m_;
 public:
     _LIBCPP_HIDE_FROM_ABI month() = default;
-    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr month(unsigned __val) noexcept : __m(static_cast<unsigned char>(__val)) {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr month& operator++()    noexcept { ++__m; return *this; }
+    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr month(unsigned __val) noexcept : __m_(static_cast<unsigned char>(__val)) {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr month& operator++()    noexcept { ++__m_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr month  operator++(int) noexcept { month __tmp = *this; ++(*this); return __tmp; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr month& operator--()    noexcept { --__m; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr month& operator--()    noexcept { --__m_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr month  operator--(int) noexcept { month __tmp = *this; --(*this); return __tmp; }
     _LIBCPP_HIDE_FROM_ABI        constexpr month& operator+=(const months& __m1) noexcept;
     _LIBCPP_HIDE_FROM_ABI        constexpr month& operator-=(const months& __m1) noexcept;
-    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr operator unsigned() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __m >= 1 && __m <= 12; }
+    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr operator unsigned() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __m_ >= 1 && __m_ <= 12; }
 };
 
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const month& __lhs, const month& __rhs) noexcept
 { return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr

libcxx/include/__chrono/month_weekday.h

 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class month_weekday {
 private:
-    chrono::month __m;
-    chrono::weekday_indexed __wdi;
+    chrono::month __m_;
+    chrono::weekday_indexed __wdi_;
 public:
     _LIBCPP_HIDE_FROM_ABI constexpr month_weekday(const chrono::month& __mval, const chrono::weekday_indexed& __wdival) noexcept
-        : __m{__mval}, __wdi{__wdival} {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month                     month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool                                 ok() const noexcept { return __m.ok() && __wdi.ok(); }
+        : __m_{__mval}, __wdi_{__wdival} {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month                     month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool                                 ok() const noexcept { return __m_.ok() && __wdi_.ok(); }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
 { return __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator!=(const month_weekday& __lhs, const month_weekday& __rhs) noexcept

 { return month_weekday{__rhs, __lhs}; }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 month_weekday operator/(const weekday_indexed& __lhs, int __rhs) noexcept
 { return month_weekday{month(__rhs), __lhs}; }
 
 
 class month_weekday_last {
-    chrono::month        __m;
-    chrono::weekday_last __wdl;
+    chrono::month        __m_;
+    chrono::weekday_last __wdl_;
   public:
     _LIBCPP_HIDE_FROM_ABI constexpr month_weekday_last(const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
-        : __m{__mval}, __wdl{__wdlval} {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month               month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool                           ok() const noexcept { return __m.ok() && __wdl.ok(); }
+        : __m_{__mval}, __wdl_{__wdlval} {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month               month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool                           ok() const noexcept { return __m_.ok() && __wdl_.ok(); }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
 { return __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator!=(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept

libcxx/include/__chrono/monthday.h

 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class month_day {
 private:
-   chrono::month __m;
-   chrono::day   __d;
+   chrono::month __m_;
+   chrono::day   __d_;
 public:
     _LIBCPP_HIDE_FROM_ABI month_day() = default;
     _LIBCPP_HIDE_FROM_ABI constexpr month_day(const chrono::month& __mval, const chrono::day& __dval) noexcept
-        : __m{__mval}, __d{__dval} {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::day   day()   const noexcept { return __d; }
+        : __m_{__mval}, __d_{__dval} {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::day   day()   const noexcept { return __d_; }
     _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept;
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool month_day::ok() const noexcept
 {
-    if (!__m.ok()) return false;
-    const unsigned __dval = static_cast<unsigned>(__d);
+    if (!__m_.ok()) return false;
+    const unsigned __dval = static_cast<unsigned>(__d_);
     if (__dval < 1 || __dval > 31) return false;
     if (__dval <= 29) return true;
 //  Now we've got either 30 or 31
-    const unsigned __mval = static_cast<unsigned>(__m);
+    const unsigned __mval = static_cast<unsigned>(__m_);
     if (__mval == 2) return false;
     if (__mval == 4 || __mval == 6 || __mval == 9 || __mval == 11)
         return __dval == 30;
     return true;
 }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const month_day& __lhs, const month_day& __rhs) noexcept

 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator>=(const month_day& __lhs, const month_day& __rhs) noexcept
 { return !(__lhs < __rhs); }
 
 
 
 class month_day_last {
 private:
-    chrono::month __m;
+    chrono::month __m_;
 public:
     _LIBCPP_HIDE_FROM_ABI explicit constexpr month_day_last(const chrono::month& __val) noexcept
-        : __m{__val} {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __m.ok(); }
+        : __m_{__val} {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __m_.ok(); }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
 { return __lhs.month() == __rhs.month(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator!=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept

libcxx/include/__chrono/weekday.h

 namespace chrono
 {
 
 class weekday_indexed;
 class weekday_last;
 
 class weekday {
 private:
-    unsigned char __wd;
+    unsigned char __wd_;
     _LIBCPP_HIDE_FROM_ABI static constexpr unsigned char __weekday_from_days(int __days) noexcept;
 public:
   _LIBCPP_HIDE_FROM_ABI weekday() = default;
-  _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(unsigned __val) noexcept : __wd(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
+  _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(unsigned __val) noexcept : __wd_(static_cast<unsigned char>(__val == 7 ? 0 : __val)) {}
   _LIBCPP_HIDE_FROM_ABI inline constexpr          weekday(const sys_days& __sysd) noexcept
-          : __wd(__weekday_from_days(__sysd.time_since_epoch().count())) {}
+          : __wd_(__weekday_from_days(__sysd.time_since_epoch().count())) {}
   _LIBCPP_HIDE_FROM_ABI inline explicit constexpr weekday(const local_days& __locd) noexcept
-          : __wd(__weekday_from_days(__locd.time_since_epoch().count())) {}
+          : __wd_(__weekday_from_days(__locd.time_since_epoch().count())) {}
 
-  _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator++()    noexcept { __wd = (__wd == 6 ? 0 : __wd + 1); return *this; }
+  _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator++()    noexcept { __wd_ = (__wd_ == 6 ? 0 : __wd_ + 1); return *this; }
   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday  operator++(int) noexcept { weekday __tmp = *this; ++(*this); return __tmp; }
-  _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator--()    noexcept { __wd = (__wd == 0 ? 6 : __wd - 1); return *this; }
+  _LIBCPP_HIDE_FROM_ABI inline constexpr weekday& operator--()    noexcept { __wd_ = (__wd_ == 0 ? 6 : __wd_ - 1); return *this; }
   _LIBCPP_HIDE_FROM_ABI inline constexpr weekday  operator--(int) noexcept { weekday __tmp = *this; --(*this); return __tmp; }
   _LIBCPP_HIDE_FROM_ABI        constexpr weekday& operator+=(const days& __dd) noexcept;
   _LIBCPP_HIDE_FROM_ABI        constexpr weekday& operator-=(const days& __dd) noexcept;
-  _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned c_encoding()   const noexcept { return __wd; }
-  _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned iso_encoding() const noexcept { return __wd == 0u ? 7 : __wd; }
-  _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd <= 6; }
+  _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned c_encoding()   const noexcept { return __wd_; }
+  _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned iso_encoding() const noexcept { return __wd_ == 0u ? 7 : __wd_; }
+  _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd_ <= 6; }
   _LIBCPP_HIDE_FROM_ABI        constexpr weekday_indexed operator[](unsigned __index) const noexcept;
   _LIBCPP_HIDE_FROM_ABI        constexpr weekday_last    operator[](last_spec) const noexcept;
 };
 
 
 // https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 unsigned char weekday::__weekday_from_days(int __days) noexcept

 { *this = *this + __dd; return *this; }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 weekday& weekday::operator-=(const days& __dd) noexcept
 { *this = *this - __dd; return *this; }
 
 class weekday_indexed {
 private:
-    chrono::weekday __wd;
-    unsigned char   __idx;
+    chrono::weekday __wd_;
+    unsigned char   __idx_;
 public:
     _LIBCPP_HIDE_FROM_ABI weekday_indexed() = default;
     _LIBCPP_HIDE_FROM_ABI inline constexpr weekday_indexed(const chrono::weekday& __wdval, unsigned __idxval) noexcept
-        : __wd{__wdval}, __idx(__idxval) {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned                 index() const noexcept { return __idx; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd.ok() && __idx >= 1 && __idx <= 5; }
+        : __wd_{__wdval}, __idx_(__idxval) {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday weekday() const noexcept { return __wd_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned                 index() const noexcept { return __idx_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __wd_.ok() && __idx_ >= 1 && __idx_ <= 5; }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
 { return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
 { return !(__lhs == __rhs); }
 
 
 class weekday_last {
 private:
-    chrono::weekday __wd;
+    chrono::weekday __wd_;
 public:
     _LIBCPP_HIDE_FROM_ABI explicit constexpr weekday_last(const chrono::weekday& __val) noexcept
-        : __wd{__val} {}
-    _LIBCPP_HIDE_FROM_ABI constexpr chrono::weekday weekday() const noexcept { return __wd; }
-    _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept { return __wd.ok(); }
+        : __wd_{__val} {}
+    _LIBCPP_HIDE_FROM_ABI constexpr chrono::weekday weekday() const noexcept { return __wd_; }
+    _LIBCPP_HIDE_FROM_ABI constexpr bool ok() const noexcept { return __wd_.ok(); }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
 { return __lhs.weekday() == __rhs.weekday(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept

libcxx/include/__chrono/year.h

 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class year {
 private:
-    short __y;
+    short __y_;
 public:
     _LIBCPP_HIDE_FROM_ABI year() = default;
-    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr year(int __val) noexcept : __y(static_cast<short>(__val)) {}
+    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr year(int __val) noexcept : __y_(static_cast<short>(__val)) {}
 
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year& operator++()    noexcept { ++__y; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year& operator++()    noexcept { ++__y_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year& operator--()    noexcept { --__y; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year& operator--()    noexcept { --__y_; return *this; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; }
     _LIBCPP_HIDE_FROM_ABI        constexpr year& operator+=(const years& __dy) noexcept;
     _LIBCPP_HIDE_FROM_ABI        constexpr year& operator-=(const years& __dy) noexcept;
     _LIBCPP_HIDE_FROM_ABI inline constexpr year operator+() const noexcept { return *this; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year operator-() const noexcept { return year{-__y}; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year operator-() const noexcept { return year{-__y_}; }
 
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool is_leap() const noexcept { return __y % 4 == 0 && (__y % 100 != 0 || __y % 400 == 0); }
-    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr operator int() const noexcept { return __y; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool is_leap() const noexcept { return __y_ % 4 == 0 && (__y_ % 100 != 0 || __y_ % 400 == 0); }
+    _LIBCPP_HIDE_FROM_ABI explicit inline constexpr operator int() const noexcept { return __y_; }
     _LIBCPP_HIDE_FROM_ABI        constexpr bool ok() const noexcept;
     _LIBCPP_HIDE_FROM_ABI static inline constexpr year min() noexcept { return year{-32767}; }
     _LIBCPP_HIDE_FROM_ABI static inline constexpr year max() noexcept { return year{ 32767}; }
 };
 
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const year& __lhs, const year& __rhs) noexcept

 { *this = *this + __dy; return *this; }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 year& year::operator-=(const years& __dy) noexcept
 { *this = *this - __dy; return *this; }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool year::ok() const noexcept
-{ return static_cast<int>(min()) <= __y && __y <= static_cast<int>(max()); }
+{ return static_cast<int>(min()) <= __y_ && __y_ <= static_cast<int>(max()); }
 } // namespace chrono
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP_STD_VER > 17
 
 _LIBCPP_POP_MACROS
 
 #endif // _LIBCPP___CHRONO_YEAR_H

libcxx/include/__chrono/year_month.h

 #if _LIBCPP_STD_VER > 17
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class year_month {
-    chrono::year  __y;
-    chrono::month __m;
+    chrono::year  __y_;
+    chrono::month __m_;
 public:
     _LIBCPP_HIDE_FROM_ABI year_month() = default;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month(const chrono::year& __yval, const chrono::month& __mval) noexcept
-        : __y{__yval}, __m{__mval} {}
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year  year()  const noexcept { return __y; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const months& __dm) noexcept { this->__m += __dm; return *this; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const months& __dm) noexcept { this->__m -= __dm; return *this; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const years& __dy)  noexcept { this->__y += __dy; return *this; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const years& __dy)  noexcept { this->__y -= __dy; return *this; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok(); }
+        : __y_{__yval}, __m_{__mval} {}
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year  year()  const noexcept { return __y_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const months& __dm) noexcept { this->__m_ += __dm; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const months& __dm) noexcept { this->__m_ -= __dm; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator+=(const years& __dy)  noexcept { this->__y_ += __dy; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr year_month& operator-=(const years& __dy)  noexcept { this->__y_ -= __dy; return *this; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __y_.ok() && __m_.ok(); }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 year_month operator/(const year& __y, const month& __m) noexcept { return year_month{__y, __m}; }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 year_month operator/(const year& __y, int __m) noexcept { return year_month{__y, month(__m)}; }
 

libcxx/include/__chrono/year_month_day.h

 
 namespace chrono
 {
 
 class year_month_day_last;
 
 class year_month_day {
 private:
-    chrono::year  __y;
-    chrono::month __m;
-    chrono::day   __d;
+    chrono::year  __y_;
+    chrono::month __m_;
+    chrono::day   __d_;
 public:
      _LIBCPP_HIDE_FROM_ABI year_month_day() = default;
      _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day(
             const chrono::year& __yval, const chrono::month& __mval, const chrono::day& __dval) noexcept
-            : __y{__yval}, __m{__mval}, __d{__dval} {}
+            : __y_{__yval}, __m_{__mval}, __d_{__dval} {}
      _LIBCPP_HIDE_FROM_ABI        constexpr year_month_day(const year_month_day_last& __ymdl) noexcept;
      _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day(const sys_days& __sysd) noexcept
             : year_month_day(__from_days(__sysd.time_since_epoch())) {}
      _LIBCPP_HIDE_FROM_ABI inline explicit constexpr year_month_day(const local_days& __locd) noexcept
             : year_month_day(__from_days(__locd.time_since_epoch())) {}
 
      _LIBCPP_HIDE_FROM_ABI        constexpr year_month_day& operator+=(const months& __dm) noexcept;
      _LIBCPP_HIDE_FROM_ABI        constexpr year_month_day& operator-=(const months& __dm) noexcept;
      _LIBCPP_HIDE_FROM_ABI        constexpr year_month_day& operator+=(const years& __dy)  noexcept;
      _LIBCPP_HIDE_FROM_ABI        constexpr year_month_day& operator-=(const years& __dy)  noexcept;
 
-     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year   year() const noexcept { return __y; }
-     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m; }
-     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::day     day() const noexcept { return __d; }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year   year() const noexcept { return __y_; }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month month() const noexcept { return __m_; }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::day     day() const noexcept { return __d_; }
      _LIBCPP_HIDE_FROM_ABI inline constexpr operator   sys_days() const noexcept          { return   sys_days{__to_days()}; }
      _LIBCPP_HIDE_FROM_ABI inline explicit constexpr operator local_days() const noexcept { return local_days{__to_days()}; }
 
      _LIBCPP_HIDE_FROM_ABI        constexpr bool             ok() const noexcept;
 
      _LIBCPP_HIDE_FROM_ABI static constexpr year_month_day __from_days(days __d) noexcept;
      _LIBCPP_HIDE_FROM_ABI constexpr days __to_days() const noexcept;
 };

 
 // https://howardhinnant.github.io/date_algorithms.html#days_from_civil
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 days year_month_day::__to_days() const noexcept
 {
     static_assert(numeric_limits<unsigned>::digits >= 18, "");
     static_assert(numeric_limits<int>::digits >= 20     , "");
 
-    const int      __yr  = static_cast<int>(__y) - (__m <= February);
-    const unsigned __mth = static_cast<unsigned>(__m);
-    const unsigned __dy  = static_cast<unsigned>(__d);
+    const int      __yr  = static_cast<int>(__y_) - (__m_ <= February);
+    const unsigned __mth = static_cast<unsigned>(__m_);
+    const unsigned __dy  = static_cast<unsigned>(__d_);
 
     const int      __era = (__yr >= 0 ? __yr : __yr - 399) / 400;
     const unsigned __yoe = static_cast<unsigned>(__yr - __era * 400);                // [0, 399]
     const unsigned __doy = (153 * (__mth + (__mth > 2 ? -3 : 9)) + 2) / 5 + __dy-1;  // [0, 365]
     const unsigned __doe = __yoe * 365 + __yoe/4 - __yoe/100 + __doy;                // [0, 146096]
     return days{__era * 146097 + static_cast<int>(__doe) - 719468};
 }
 

 
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day& year_month_day::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
 
 class year_month_day_last {
 private:
-    chrono::year           __y;
-    chrono::month_day_last __mdl;
+    chrono::year           __y_;
+    chrono::month_day_last __mdl_;
 public:
      _LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
-        : __y{__yval}, __mdl{__mdlval} {}
+        : __y_{__yval}, __mdl_{__mdlval} {}
 
      _LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator+=(const months& __m) noexcept;
      _LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator-=(const months& __m) noexcept;
      _LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator+=(const years& __y)  noexcept;
      _LIBCPP_HIDE_FROM_ABI constexpr year_month_day_last& operator-=(const years& __y)  noexcept;
 
-     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year                     year() const noexcept { return __y; }
-     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month                   month() const noexcept { return __mdl.month(); }
-     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month_day_last month_day_last() const noexcept { return __mdl; }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year                     year() const noexcept { return __y_; }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month                   month() const noexcept { return __mdl_.month(); }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month_day_last month_day_last() const noexcept { return __mdl_; }
      _LIBCPP_HIDE_FROM_ABI        constexpr chrono::day                       day() const noexcept;
      _LIBCPP_HIDE_FROM_ABI inline constexpr operator                     sys_days() const noexcept { return   sys_days{year()/month()/day()}; }
      _LIBCPP_HIDE_FROM_ABI inline explicit constexpr operator          local_days() const noexcept { return local_days{year()/month()/day()}; }
-     _LIBCPP_HIDE_FROM_ABI inline constexpr bool                               ok() const noexcept { return __y.ok() && __mdl.ok(); }
+     _LIBCPP_HIDE_FROM_ABI inline constexpr bool                               ok() const noexcept { return __y_.ok() && __mdl_.ok(); }
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 chrono::day year_month_day_last::day() const noexcept
 {
     constexpr chrono::day __d[] =
     {
         chrono::day(31), chrono::day(28), chrono::day(31),
         chrono::day(30), chrono::day(31), chrono::day(30),
         chrono::day(31), chrono::day(31), chrono::day(30),
         chrono::day(31), chrono::day(30), chrono::day(31)
     };
-    return (month() != February || !__y.is_leap()) && month().ok() ?
+    return (month() != February || !__y_.is_leap()) && month().ok() ?
         __d[static_cast<unsigned>(month()) - 1] : chrono::day{29};
 }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
 { return __lhs.year() == __rhs.year() && __lhs.month_day_last() == __rhs.month_day_last(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr

 
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last& year_month_day_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last& year_month_day_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last& year_month_day_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_day_last& year_month_day_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 year_month_day::year_month_day(const year_month_day_last& __ymdl) noexcept
-    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}
+    : __y_{__ymdl.year()}, __m_{__ymdl.month()}, __d_{__ymdl.day()} {}
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool year_month_day::ok() const noexcept
 {
-    if (!__y.ok() || !__m.ok()) return false;
-    return chrono::day{1} <= __d && __d <= (__y / __m / last).day();
+    if (!__y_.ok() || !__m_.ok()) return false;
+    return chrono::day{1} <= __d_ && __d_ <= (__y_ / __m_ / last).day();
 }
 
 } // namespace chrono
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP_STD_VER > 17
 
 #endif // _LIBCPP___CHRONO_YEAR_MONTH_DAY_H

libcxx/include/__chrono/year_month_weekday.h

 #if _LIBCPP_STD_VER > 17
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 namespace chrono
 {
 
 class year_month_weekday {
-    chrono::year            __y;
-    chrono::month           __m;
-    chrono::weekday_indexed __wdi;
+    chrono::year            __y_;
+    chrono::month           __m_;
+    chrono::weekday_indexed __wdi_;
 public:
     _LIBCPP_HIDE_FROM_ABI year_month_weekday() = default;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday(const chrono::year& __yval, const chrono::month& __mval,
                                const chrono::weekday_indexed& __wdival) noexcept
-        : __y{__yval}, __m{__mval}, __wdi{__wdival} {}
+        : __y_{__yval}, __m_{__mval}, __wdi_{__wdival} {}
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday(const sys_days& __sysd) noexcept
             : year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
     _LIBCPP_HIDE_FROM_ABI inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
             : year_month_weekday(__from_days(__locd.time_since_epoch())) {}
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator+=(const months&) noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator-=(const months&) noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator+=(const years&)  noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday& operator-=(const years&)  noexcept;
 
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year                       year() const noexcept { return __y; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month                     month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday                 weekday() const noexcept { return __wdi.weekday(); }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned                          index() const noexcept { return __wdi.index(); }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year                       year() const noexcept { return __y_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month                     month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday                 weekday() const noexcept { return __wdi_.weekday(); }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr unsigned                          index() const noexcept { return __wdi_.index(); }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi_; }
 
     _LIBCPP_HIDE_FROM_ABI inline constexpr                       operator sys_days() const noexcept { return   sys_days{__to_days()}; }
     _LIBCPP_HIDE_FROM_ABI inline explicit constexpr operator            local_days() const noexcept { return local_days{__to_days()}; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept
     {
-        if (!__y.ok() || !__m.ok() || !__wdi.ok()) return false;
-        if (__wdi.index() <= 4) return true;
+        if (!__y_.ok() || !__m_.ok() || !__wdi_.ok()) return false;
+        if (__wdi_.index() <= 4) return true;
         auto __nth_weekday_day =
-            __wdi.weekday() -
-            chrono::weekday{static_cast<sys_days>(__y / __m / 1)} +
-            days{(__wdi.index() - 1) * 7 + 1};
+            __wdi_.weekday() -
+            chrono::weekday{static_cast<sys_days>(__y_ / __m_ / 1)} +
+            days{(__wdi_.index() - 1) * 7 + 1};
         return static_cast<unsigned>(__nth_weekday_day.count()) <=
-               static_cast<unsigned>((__y / __m / last).day());
+               static_cast<unsigned>((__y_ / __m_ / last).day());
     }
 
     _LIBCPP_HIDE_FROM_ABI static constexpr year_month_weekday __from_days(days __d) noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr days __to_days() const noexcept;
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 year_month_weekday year_month_weekday::__from_days(days __d) noexcept
 {
     const sys_days      __sysd{__d};
     const chrono::weekday __wd = chrono::weekday(__sysd);
     const year_month_day __ymd = year_month_day(__sysd);
     return year_month_weekday{__ymd.year(), __ymd.month(),
                               __wd[(static_cast<unsigned>(__ymd.day())-1)/7+1]};
 }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 days year_month_weekday::__to_days() const noexcept
 {
-    const sys_days __sysd = sys_days(__y/__m/1);
-    return (__sysd + (__wdi.weekday() - chrono::weekday(__sysd) + days{(__wdi.index()-1)*7}))
+    const sys_days __sysd = sys_days(__y_/__m_/1);
+    return (__sysd + (__wdi_.weekday() - chrono::weekday(__sysd) + days{(__wdi_.index()-1)*7}))
                 .time_since_epoch();
 }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
 { return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr

 
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
 _LIBCPP_HIDE_FROM_ABI inline constexpr year_month_weekday& year_month_weekday::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
 
 class year_month_weekday_last {
 private:
-    chrono::year         __y;
-    chrono::month        __m;
-    chrono::weekday_last __wdl;
+    chrono::year         __y_;
+    chrono::month        __m_;
+    chrono::weekday_last __wdl_;
 public:
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last(const chrono::year& __yval, const chrono::month& __mval,
                                       const chrono::weekday_last& __wdlval) noexcept
-                : __y{__yval}, __m{__mval}, __wdl{__wdlval} {}
+                : __y_{__yval}, __m_{__mval}, __wdl_{__wdlval} {}
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator+=(const years& __dy)  noexcept;
     _LIBCPP_HIDE_FROM_ABI constexpr year_month_weekday_last& operator-=(const years& __dy)  noexcept;
 
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year                 year() const noexcept { return __y; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month               month() const noexcept { return __m; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday           weekday() const noexcept { return __wdl.weekday(); }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::year                 year() const noexcept { return __y_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::month               month() const noexcept { return __m_; }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday           weekday() const noexcept { return __wdl_.weekday(); }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl_; }
     _LIBCPP_HIDE_FROM_ABI inline constexpr operator                 sys_days() const noexcept { return   sys_days{__to_days()}; }
     _LIBCPP_HIDE_FROM_ABI inline explicit constexpr operator      local_days() const noexcept { return local_days{__to_days()}; }
-    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok() && __wdl.ok(); }
+    _LIBCPP_HIDE_FROM_ABI inline constexpr bool ok() const noexcept { return __y_.ok() && __m_.ok() && __wdl_.ok(); }
 
     _LIBCPP_HIDE_FROM_ABI constexpr days __to_days() const noexcept;
 
 };
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 days year_month_weekday_last::__to_days() const noexcept
 {
-    const sys_days __last = sys_days{__y/__m/last};
-    return (__last - (chrono::weekday{__last} - __wdl.weekday())).time_since_epoch();
+    const sys_days __last = sys_days{__y_/__m_/last};
+    return (__last - (chrono::weekday{__last} - __wdl_.weekday())).time_since_epoch();
 
 }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr
 bool operator==(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
 { return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
 
 _LIBCPP_HIDE_FROM_ABI inline constexpr

libcxx/include/__iterator/reverse_iterator.h

: public iterator<typename iterator_traits<_Iter>::iterator_category,
                       typename iterator_traits<_Iter>::difference_type,
                       typename iterator_traits<_Iter>::pointer,
                       typename iterator_traits<_Iter>::reference>
 #endif
 {
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 private:
 #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
-    _Iter __t; // no longer used as of LWG #2360, not removed due to ABI break
+    _Iter __t_; // no longer used as of LWG #2360, not removed due to ABI break
 #endif
 
 #if _LIBCPP_STD_VER > 17
     static_assert(__is_cpp17_bidirectional_iterator<_Iter>::value || bidirectional_iterator<_Iter>,
         "reverse_iterator<It> requires It to be a bidirectional iterator.");
 #endif // _LIBCPP_STD_VER > 17
 
 protected:

 #else
     using value_type = typename iterator_traits<_Iter>::value_type;
     using difference_type = typename iterator_traits<_Iter>::difference_type;
     using reference = typename iterator_traits<_Iter>::reference;
 #endif
 
 #ifndef _LIBCPP_ABI_NO_ITERATOR_BASES
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator() : __t(), current() {}
+    reverse_iterator() : __t_(), current() {}
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
+    explicit reverse_iterator(_Iter __x) : __t_(__x), current(__x) {}
 
     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value && is_convertible<_Up const&, _Iter>::value
     > >
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator(const reverse_iterator<_Up>& __u)
-        : __t(__u.base()), current(__u.base())
+        : __t_(__u.base()), current(__u.base())
     { }
 
     template <class _Up, class = __enable_if_t<
         !is_same<_Up, _Iter>::value &&
         is_convertible<_Up const&, _Iter>::value &&
         is_assignable<_Iter&, _Up const&>::value
     > >
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator& operator=(const reverse_iterator<_Up>& __u) {
-        __t = current = __u.base();
+        __t_ = current = __u.base();
         return *this;
     }
 #else
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     reverse_iterator() : current() {}
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     explicit reverse_iterator(_Iter __x) : current(__x) {}

libcxx/include/__iterator/wrap_iter.h

public:
     typedef typename iterator_traits<iterator_type>::pointer           pointer;
     typedef typename iterator_traits<iterator_type>::reference         reference;
     typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
 #if _LIBCPP_STD_VER > 17
     typedef contiguous_iterator_tag                                    iterator_concept;
 #endif
 
 private:
-    iterator_type __i;
+    iterator_type __i_;
 public:
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter() _NOEXCEPT
-                : __i()
+                : __i_()
     {
         _VSTD::__debug_db_insert_i(this);
     }
     template <class _Up> _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
         __wrap_iter(const __wrap_iter<_Up>& __u,
             typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = nullptr) _NOEXCEPT
-            : __i(__u.base())
+            : __i_(__u.base())
     {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
       if (!__libcpp_is_constant_evaluated())
         __get_db()->__iterator_copy(this, _VSTD::addressof(__u));
 #endif
     }
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
~__wrap_iter()
       if (!__libcpp_is_constant_evaluated())
         __get_db()->__erase_i(this);
     }
 #endif
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference operator*() const _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                              "Attempted to dereference a non-dereferenceable iterator");
-        return *__i;
+        return *__i_;
     }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 pointer operator->() const _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                              "Attempted to dereference a non-dereferenceable iterator");
-        return _VSTD::__to_address(__i);
+        return _VSTD::__to_address(__i_);
     }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator++() _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
                              "Attempted to increment a non-incrementable iterator");
-        ++__i;
+        ++__i_;
         return *this;
     }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator++(int) _NOEXCEPT
         {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
 
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator--() _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__decrementable(this),
                              "Attempted to decrement a non-decrementable iterator");
-        --__i;
+        --__i_;
         return *this;
     }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator--(int) _NOEXCEPT
         {__wrap_iter __tmp(*this); --(*this); return __tmp;}
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT
         {__wrap_iter __w(*this); __w += __n; return __w;}
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator+=(difference_type __n) _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__addable(this, __n),
                              "Attempted to add/subtract an iterator outside its valid range");
-        __i += __n;
+        __i_ += __n;
         return *this;
     }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter  operator- (difference_type __n) const _NOEXCEPT
         {return *this + (-__n);}
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 __wrap_iter& operator-=(difference_type __n) _NOEXCEPT
         {*this += -__n; return *this;}
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 reference    operator[](difference_type __n) const _NOEXCEPT
     {
         _LIBCPP_DEBUG_ASSERT(__get_const_db()->__subscriptable(this, __n),
                              "Attempted to subscript an iterator outside its valid range");
-        return __i[__n];
+        return __i_[__n];
     }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 iterator_type base() const _NOEXCEPT {return __i;}
+    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 iterator_type base() const _NOEXCEPT {return __i_;}
 
 private:
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit __wrap_iter(const void* __p, iterator_type __x) _NOEXCEPT : __i(__x)
+    explicit __wrap_iter(const void* __p, iterator_type __x) _NOEXCEPT : __i_(__x)
     {
         (void)__p;
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
       if (!__libcpp_is_constant_evaluated())
         __get_db()->__insert_ic(this, __p);
 #endif
     }
 

libcxx/include/__locale

 // template <class CharT> class collate_byname;
 
 template <class _CharT> class _LIBCPP_TEMPLATE_VIS collate_byname;
 
 template <>
 class _LIBCPP_TYPE_VIS collate_byname<char>
     : public collate<char>
 {
-    locale_t __l;
+    locale_t __l_;
 public:
     typedef char char_type;
     typedef basic_string<char_type> string_type;
 
     explicit collate_byname(const char* __n, size_t __refs = 0);
     explicit collate_byname(const string& __n, size_t __refs = 0);
 
 protected:
     ~collate_byname();
     virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
                            const char_type* __lo2, const char_type* __hi2) const;
     virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const;
 };
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS collate_byname<wchar_t>
     : public collate<wchar_t>
 {
-    locale_t __l;
+    locale_t __l_;
 public:
     typedef wchar_t char_type;
     typedef basic_string<char_type> string_type;
 
     explicit collate_byname(const char* __n, size_t __refs = 0);
     explicit collate_byname(const string& __n, size_t __refs = 0);
 
 protected:

 // template <class CharT> class ctype_byname;
 
 template <class _CharT> class _LIBCPP_TEMPLATE_VIS ctype_byname;
 
 template <>
 class _LIBCPP_TYPE_VIS ctype_byname<char>
     : public ctype<char>
 {
-    locale_t __l;
+    locale_t __l_;
 
 public:
     explicit ctype_byname(const char*, size_t = 0);
     explicit ctype_byname(const string&, size_t = 0);
 
 protected:
     ~ctype_byname();
     virtual char_type do_toupper(char_type) const;
     virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
     virtual char_type do_tolower(char_type) const;
     virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
 };
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS ctype_byname<wchar_t>
     : public ctype<wchar_t>
 {
-    locale_t __l;
+    locale_t __l_;
 
 public:
     explicit ctype_byname(const char*, size_t = 0);
     explicit ctype_byname(const string&, size_t = 0);
 
 protected:
     ~ctype_byname();
     virtual bool do_is(mask __m, char_type __c) const;

 // template <> class codecvt<wchar_t, char, mbstate_t>
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS codecvt<wchar_t, char, mbstate_t>
     : public locale::facet,
       public codecvt_base
 {
-    locale_t __l;
+    locale_t __l_;
 public:
     typedef wchar_t   intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     explicit codecvt(size_t __refs = 0);
 
     _LIBCPP_INLINE_VISIBILITY

libcxx/include/__memory/shared_ptr.h

 basic_ostream<_CharT, _Traits>&
 operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
 
 
 #if !defined(_LIBCPP_HAS_NO_THREADS)
 
 class _LIBCPP_TYPE_VIS __sp_mut
 {
-    void* __lx;
+    void* __lx_;
 public:
     void lock() _NOEXCEPT;
     void unlock() _NOEXCEPT;
 
 private:
     _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
     __sp_mut(const __sp_mut&);
     __sp_mut& operator=(const __sp_mut&);

libcxx/include/__random/normal_distribution.h

public:
             {return __x.__mean_ == __y.__mean_ && __x.__stddev_ == __y.__stddev_;}
         friend _LIBCPP_INLINE_VISIBILITY
             bool operator!=(const param_type& __x, const param_type& __y)
             {return !(__x == __y);}
     };
 
 private:
     param_type __p_;
-    result_type _V_;
-    bool _V_hot_;
+    result_type __v_;
+    bool __v_hot_;
 
 public:
     // constructors and reset functions
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_INLINE_VISIBILITY
     normal_distribution() : normal_distribution(0) {}
     _LIBCPP_INLINE_VISIBILITY
     explicit normal_distribution(result_type __mean, result_type __stddev = 1)
-        : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
+        : __p_(param_type(__mean, __stddev)), __v_hot_(false) {}
 #else
     _LIBCPP_INLINE_VISIBILITY
     explicit normal_distribution(result_type __mean = 0,
                                  result_type __stddev = 1)
         : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
 #endif
     _LIBCPP_INLINE_VISIBILITY
     explicit normal_distribution(const param_type& __p)
-        : __p_(__p), _V_hot_(false) {}
+        : __p_(__p), __v_hot_(false) {}
     _LIBCPP_INLINE_VISIBILITY
-    void reset() {_V_hot_ = false;}
+    void reset() {__v_hot_ = false;}
 
     // generating functions
     template<class _URNG>
         _LIBCPP_INLINE_VISIBILITY
         result_type operator()(_URNG& __g)
         {return (*this)(__g, __p_);}
     template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
 
#endif
     _LIBCPP_INLINE_VISIBILITY
     result_type min() const {return -numeric_limits<result_type>::infinity();}
     _LIBCPP_INLINE_VISIBILITY
     result_type max() const {return numeric_limits<result_type>::infinity();}
 
     friend _LIBCPP_INLINE_VISIBILITY
         bool operator==(const normal_distribution& __x,
                         const normal_distribution& __y)
-        {return __x.__p_ == __y.__p_ && __x._V_hot_ == __y._V_hot_ &&
-                (!__x._V_hot_ || __x._V_ == __y._V_);}
+        {return __x.__p_ == __y.__p_ && __x.__v_hot_ == __y.__v_hot_ &&
+                (!__x.__v_hot_ || __x.__v_ == __y.__v_);}
     friend _LIBCPP_INLINE_VISIBILITY
         bool operator!=(const normal_distribution& __x,
                         const normal_distribution& __y)
         {return !(__x == __y);}
 
     template <class _CharT, class _Traits, class _RT>
     friend
     basic_ostream<_CharT, _Traits>&

 
 template <class _RealType>
 template<class _URNG>
 _RealType
 normal_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
 {
     static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
     result_type _Up;
-    if (_V_hot_)
+    if (__v_hot_)
     {
-        _V_hot_ = false;
-        _Up = _V_;
+        __v_hot_ = false;
+        _Up = __v_;
     }
     else
     {
         uniform_real_distribution<result_type> _Uni(-1, 1);
         result_type __u;
         result_type __v;
         result_type __s;
         do
         {
             __u = _Uni(__g);
             __v = _Uni(__g);
             __s = __u * __u + __v * __v;
         } while (__s > 1 || __s == 0);
         result_type _Fp = _VSTD::sqrt(-2 * _VSTD::log(__s) / __s);
-        _V_ = __v * _Fp;
-        _V_hot_ = true;
+        __v_ = __v * _Fp;
+        __v_hot_ = true;
         _Up = __u * _Fp;
     }
     return _Up * __p.stddev() + __p.mean();
 }
 
 template <class _CharT, class _Traits, class _RT>
 basic_ostream<_CharT, _Traits>&
 operator<<(basic_ostream<_CharT, _Traits>& __os,
            const normal_distribution<_RT>& __x)
 {
     __save_flags<_CharT, _Traits> __lx(__os);
     typedef basic_ostream<_CharT, _Traits> _OStream;
     __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
                _OStream::scientific);
     _CharT __sp = __os.widen(' ');
     __os.fill(__sp);
-    __os << __x.mean() << __sp << __x.stddev() << __sp << __x._V_hot_;
-    if (__x._V_hot_)
-        __os << __sp << __x._V_;
+    __os << __x.mean() << __sp << __x.stddev() << __sp << __x.__v_hot_;
+    if (__x.__v_hot_)
+        __os << __sp << __x.__v_;
     return __os;
 }
 
 template <class _CharT, class _Traits, class _RT>
 basic_istream<_CharT, _Traits>&
 operator>>(basic_istream<_CharT, _Traits>& __is,
            normal_distribution<_RT>& __x)
 {
     typedef normal_distribution<_RT> _Eng;
     typedef typename _Eng::result_type result_type;
     typedef typename _Eng::param_type param_type;
     __save_flags<_CharT, _Traits> __lx(__is);
     typedef basic_istream<_CharT, _Traits> _Istream;
     __is.flags(_Istream::dec | _Istream::skipws);
     result_type __mean;
     result_type __stddev;
     result_type _Vp = 0;
     bool _V_hot = false;
     __is >> __mean >> __stddev >> _V_hot;
     if (_V_hot)
         __is >> _Vp;
     if (!__is.fail())
     {
         __x.param(param_type(__mean, __stddev));
-        __x._V_hot_ = _V_hot;
-        __x._V_ = _Vp;
+        __x.__v_hot_ = _V_hot;
+        __x.__v_ = _Vp;
     }
     return __is;
 }
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // _LIBCPP___RANDOM_NORMAL_DISTRIBUTION_H

libcxx/include/__random/shuffle_order_engine.h

 {
     static_assert(0 < __k, "shuffle_order_engine invalid parameters");
 public:
     // types
     typedef typename _Engine::result_type result_type;
 
 private:
     _Engine __e_;
-    result_type _V_[__k];
-    result_type _Y_;
+    result_type __v_[__k];
+    result_type __y_;
 
 public:
     // engine characteristics
     static _LIBCPP_CONSTEXPR const size_t table_size = __k;
 
 #ifdef _LIBCPP_CXX03_LANG
     static const result_type _Min = _Engine::_Min;
     static const result_type _Max = _Engine::_Max;
private:
     basic_istream<_CharT, _Traits>&
     operator>>(basic_istream<_CharT, _Traits>& __is,
                shuffle_order_engine<_Eng, _Kp>& __x);
 
     _LIBCPP_INLINE_VISIBILITY
     void __init()
     {
         for (size_t __i = 0; __i < __k; ++__i)
-            _V_[__i] = __e_();
-        _Y_ = __e_();
+            __v_[__i] = __e_();
+        __y_ = __e_();
     }
 
     _LIBCPP_INLINE_VISIBILITY
     result_type __eval(false_type) {return __eval2(integral_constant<bool, __k & 1>());}
     _LIBCPP_INLINE_VISIBILITY
     result_type __eval(true_type) {return __eval(__uratio<__k, _Rp>());}
 
     _LIBCPP_INLINE_VISIBILITY
template <uint64_t _Np, uint64_t _Dp>
         _LIBCPP_INLINE_VISIBILITY
         typename enable_if
         <
             __uratio<_Np, _Dp>::num <= 0xFFFFFFFFFFFFFFFFull / (_Max - _Min),
             result_type
         >::type
         __eval(__uratio<_Np, _Dp>)
         {
-            const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (_Y_ - _Min)
+            const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (__y_ - _Min)
                                                    / __uratio<_Np, _Dp>::den);
-            _Y_ = _V_[__j];
-            _V_[__j] = __e_();
-            return _Y_;
+            __y_ = __v_[__j];
+            __v_[__j] = __e_();
+            return __y_;
         }
 
     template <uint64_t __n, uint64_t __d>
         _LIBCPP_INLINE_VISIBILITY
         result_type __evalf()
         {
             const double _Fp = __d == 0 ?
                 __n / (2. * 0x8000000000000000ull) :
                 __n / (double)__d;
-            const size_t __j = static_cast<size_t>(_Fp * (_Y_ - _Min));
-            _Y_ = _V_[__j];
-            _V_[__j] = __e_();
-            return _Y_;
+            const size_t __j = static_cast<size_t>(_Fp * (__y_ - _Min));
+            __y_ = __v_[__j];
+            __v_[__j] = __e_();
+            return __y_;
         }
 };
 
 template<class _Engine, size_t __k>
     _LIBCPP_CONSTEXPR const size_t shuffle_order_engine<_Engine, __k>::table_size;
 
 template<class _Eng, size_t _Kp>
 bool
 operator==(
     const shuffle_order_engine<_Eng, _Kp>& __x,
     const shuffle_order_engine<_Eng, _Kp>& __y)
 {
-    return __x._Y_ == __y._Y_ && _VSTD::equal(__x._V_, __x._V_ + _Kp, __y._V_) &&
+    return __x.__y_ == __y.__y_ && _VSTD::equal(__x.__v_, __x.__v_ + _Kp, __y.__v_) &&
            __x.__e_ == __y.__e_;
 }
 
 template<class _Eng, size_t _Kp>
 inline _LIBCPP_INLINE_VISIBILITY
 bool
 operator!=(
     const shuffle_order_engine<_Eng, _Kp>& __x,
     const shuffle_order_engine<_Eng, _Kp>& __y)
 {
     return !(__x == __y);
 }
 
 template <class _CharT, class _Traits,
           class _Eng, size_t _Kp>
 basic_ostream<_CharT, _Traits>&
 operator<<(basic_ostream<_CharT, _Traits>& __os,
            const shuffle_order_engine<_Eng, _Kp>& __x)
 {
     __save_flags<_CharT, _Traits> __lx(__os);
     typedef basic_ostream<_CharT, _Traits> _Ostream;
     __os.flags(_Ostream::dec | _Ostream::left);
     _CharT __sp = __os.widen(' ');
     __os.fill(__sp);
-    __os << __x.__e_ << __sp << __x._V_[0];
+    __os << __x.__e_ << __sp << __x.__v_[0];
     for (size_t __i = 1; __i < _Kp; ++__i)
-        __os << __sp << __x._V_[__i];
-    return __os << __sp << __x._Y_;
+        __os << __sp << __x.__v_[__i];
+    return __os << __sp << __x.__y_;
 }
 
 template <class _CharT, class _Traits,
           class _Eng, size_t _Kp>
 basic_istream<_CharT, _Traits>&
 operator>>(basic_istream<_CharT, _Traits>& __is,
            shuffle_order_engine<_Eng, _Kp>& __x)
 {
     typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type;
     __save_flags<_CharT, _Traits> __lx(__is);
     typedef basic_istream<_CharT, _Traits> _Istream;
     __is.flags(_Istream::dec | _Istream::skipws);
     _Eng __e;
     result_type _Vp[_Kp+1];
     __is >> __e;
     for (size_t __i = 0; __i < _Kp+1; ++__i)
         __is >> _Vp[__i];
     if (!__is.fail())
     {
         __x.__e_ = __e;
         for (size_t __i = 0; __i < _Kp; ++__i)
-            __x._V_[__i] = _Vp[__i];
-        __x._Y_ = _Vp[_Kp];
+            __x.__v_[__i] = _Vp[__i];
+        __x.__y_ = _Vp[_Kp];
     }
     return __is;
 }
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
 #endif // _LIBCPP___RANDOM_SHUFFLE_ORDER_ENGINE_H

libcxx/include/any

 
 } // namespace __any_imp
 
 class _LIBCPP_TEMPLATE_VIS any
 {
 public:
   // construct/destruct
   _LIBCPP_INLINE_VISIBILITY
-  constexpr any() _NOEXCEPT : __h(nullptr) {}
+  constexpr any() _NOEXCEPT : __h_(nullptr) {}
 
   _LIBCPP_INLINE_VISIBILITY
-  any(any const & __other) : __h(nullptr)
+  any(any const & __other) : __h_(nullptr)
   {
-    if (__other.__h) __other.__call(_Action::_Copy, this);
+    if (__other.__h_) __other.__call(_Action::_Copy, this);
   }
 
   _LIBCPP_INLINE_VISIBILITY
-  any(any && __other) _NOEXCEPT : __h(nullptr)
+  any(any && __other) _NOEXCEPT : __h_(nullptr)
   {
-    if (__other.__h) __other.__call(_Action::_Move, this);
+    if (__other.__h_) __other.__call(_Action::_Move, this);
   }
 
   template <
       class _ValueType
     , class _Tp = decay_t<_ValueType>
     , class = enable_if_t<
         !is_same<_Tp, any>::value &&
         !__is_inplace_type<_ValueType>::value &&
class = enable_if_t<
         is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
         is_copy_constructible<_Tp>::value>
   >
   _LIBCPP_INLINE_VISIBILITY
   _Tp& emplace(initializer_list<_Up>, _Args&&...);
 
   // 6.3.3 any modifiers
   _LIBCPP_INLINE_VISIBILITY
-  void reset() _NOEXCEPT { if (__h) this->__call(_Action::_Destroy); }
+  void reset() _NOEXCEPT { if (__h_) this->__call(_Action::_Destroy); }
 
   _LIBCPP_INLINE_VISIBILITY
   void swap(any & __rhs) _NOEXCEPT;
 
   // 6.3.4 any observers
   _LIBCPP_INLINE_VISIBILITY
-  bool has_value() const _NOEXCEPT { return __h != nullptr; }
+  bool has_value() const _NOEXCEPT { return __h_ != nullptr; }
 
 #if !defined(_LIBCPP_NO_RTTI)
   _LIBCPP_INLINE_VISIBILITY
   const type_info & type() const _NOEXCEPT {
-    if (__h) {
+    if (__h_) {
         return *static_cast<type_info const *>(this->__call(_Action::_TypeInfo));
     } else {
         return typeid(void);
     }
   }
 #endif
 
 private:
     typedef __any_imp::_Action _Action;
     using _HandleFuncPtr =  void* (*)(_Action, any const *, any *, const type_info *,
       const void* __fallback_info);
 
     union _Storage {
         constexpr _Storage() : __ptr(nullptr) {}
         void *  __ptr;
         __any_imp::_Buffer __buf;
     };
 
     _LIBCPP_INLINE_VISIBILITY
     void * __call(_Action __a, any * __other = nullptr,
                   type_info const * __info = nullptr,
                    const void* __fallback_info = nullptr) const
     {
-        return __h(__a, this, __other, __info, __fallback_info);
+        return __h_(__a, this, __other, __info, __fallback_info);
     }
 
     _LIBCPP_INLINE_VISIBILITY
     void * __call(_Action __a, any * __other = nullptr,
                   type_info const * __info = nullptr,
                   const void* __fallback_info = nullptr)
     {
-        return __h(__a, this, __other, __info, __fallback_info);
+        return __h_(__a, this, __other, __info, __fallback_info);
     }
 
     template <class>
     friend struct __any_imp::_SmallHandler;
     template <class>
     friend struct __any_imp::_LargeHandler;
 
     template <class _ValueType>
     friend add_pointer_t<add_const_t<_ValueType>>
     any_cast(any const *) _NOEXCEPT;
 
     template <class _ValueType>
     friend add_pointer_t<_ValueType>
     any_cast(any *) _NOEXCEPT;
 
-    _HandleFuncPtr __h = nullptr;
-    _Storage __s;
+    _HandleFuncPtr __h_ = nullptr;
+    _Storage __s_;
 };
 
 namespace __any_imp
 {
   template <class _Tp>
   struct _LIBCPP_TEMPLATE_VIS _SmallHandler
   {
      _LIBCPP_INLINE_VISIBILITY
struct _LIBCPP_TEMPLATE_VIS _SmallHandler
     }
 
     template <class ..._Args>
     _LIBCPP_INLINE_VISIBILITY
     static _Tp& __create(any & __dest, _Args&&... __args) {
         typedef allocator<_Tp> _Alloc;
         typedef allocator_traits<_Alloc> _ATraits;
         _Alloc __a;
-        _Tp * __ret = static_cast<_Tp*>(static_cast<void*>(&__dest.__s.__buf));
+        _Tp * __ret = static_cast<_Tp*>(static_cast<void*>(&__dest.__s_.__buf));
         _ATraits::construct(__a, __ret, _VSTD::forward<_Args>(__args)...);
-        __dest.__h = &_SmallHandler::__handle;
+        __dest.__h_ = &_SmallHandler::__handle;
         return *__ret;
     }
 
   private:
     _LIBCPP_INLINE_VISIBILITY
     static void __destroy(any & __this) {
         typedef allocator<_Tp> _Alloc;
         typedef allocator_traits<_Alloc> _ATraits;
         _Alloc __a;
-        _Tp * __p = static_cast<_Tp *>(static_cast<void*>(&__this.__s.__buf));
+        _Tp * __p = static_cast<_Tp *>(static_cast<void*>(&__this.__s_.__buf));
         _ATraits::destroy(__a, __p);
-        __this.__h = nullptr;
+        __this.__h_ = nullptr;
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void __copy(any const & __this, any & __dest) {
         _SmallHandler::__create(__dest, *static_cast<_Tp const *>(
-            static_cast<void const *>(&__this.__s.__buf)));
+            static_cast<void const *>(&__this.__s_.__buf)));
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void __move(any & __this, any & __dest) {
         _SmallHandler::__create(__dest, _VSTD::move(
-            *static_cast<_Tp*>(static_cast<void*>(&__this.__s.__buf))));
+            *static_cast<_Tp*>(static_cast<void*>(&__this.__s_.__buf))));
         __destroy(__this);
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void* __get(any & __this,
                        type_info const * __info,
                        const void* __fallback_id)
     {
         if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_id))
-            return static_cast<void*>(&__this.__s.__buf);
+            return static_cast<void*>(&__this.__s_.__buf);
         return nullptr;
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void* __type_info()
     {
 #if !defined(_LIBCPP_NO_RTTI)
         return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
struct _LIBCPP_TEMPLATE_VIS _LargeHandler
     static _Tp& __create(any & __dest, _Args&&... __args) {
         typedef allocator<_Tp> _Alloc;
         typedef allocator_traits<_Alloc> _ATraits;
         typedef __allocator_destructor<_Alloc> _Dp;
         _Alloc __a;
         unique_ptr<_Tp, _Dp> __hold(_ATraits::allocate(__a, 1), _Dp(__a, 1));
         _Tp * __ret = __hold.get();
         _ATraits::construct(__a, __ret, _VSTD::forward<_Args>(__args)...);
-        __dest.__s.__ptr = __hold.release();
-        __dest.__h = &_LargeHandler::__handle;
+        __dest.__s_.__ptr = __hold.release();
+        __dest.__h_ = &_LargeHandler::__handle;
         return *__ret;
     }
 
   private:
 
     _LIBCPP_INLINE_VISIBILITY
     static void __destroy(any & __this){
         typedef allocator<_Tp> _Alloc;
         typedef allocator_traits<_Alloc> _ATraits;
         _Alloc __a;
-        _Tp * __p = static_cast<_Tp *>(__this.__s.__ptr);
+        _Tp * __p = static_cast<_Tp *>(__this.__s_.__ptr);
         _ATraits::destroy(__a, __p);
         _ATraits::deallocate(__a, __p, 1);
-        __this.__h = nullptr;
+        __this.__h_ = nullptr;
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void __copy(any const & __this, any & __dest) {
-        _LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s.__ptr));
+        _LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s_.__ptr));
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void __move(any & __this, any & __dest) {
-      __dest.__s.__ptr = __this.__s.__ptr;
-      __dest.__h = &_LargeHandler::__handle;
-      __this.__h = nullptr;
+      __dest.__s_.__ptr = __this.__s_.__ptr;
+      __dest.__h_ = &_LargeHandler::__handle;
+      __this.__h_ = nullptr;
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void* __get(any & __this, type_info const * __info,
                        void const* __fallback_info)
     {
         if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_info))
-            return static_cast<void*>(__this.__s.__ptr);
+            return static_cast<void*>(__this.__s_.__ptr);
         return nullptr;
 
     }
 
     _LIBCPP_INLINE_VISIBILITY
     static void* __type_info()
     {
 #if !defined(_LIBCPP_NO_RTTI)
         return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
 #else
         return nullptr;
 #endif
     }
   };
 
 } // namespace __any_imp
 
 
 template <class _ValueType, class _Tp, class>
-any::any(_ValueType && __v) : __h(nullptr)
+any::any(_ValueType && __v) : __h_(nullptr)
 {
   __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_ValueType>(__v));
 }
 
 template <class _ValueType, class ..._Args, class _Tp, class>
 any::any(in_place_type_t<_ValueType>, _Args&&... __args) {
   __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
 }
_Tp& any::emplace(initializer_list<_Up> __il, _Args&&... __args) {
   return __any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
 }
 
 inline _LIBCPP_INLINE_VISIBILITY
 void any::swap(any & __rhs) _NOEXCEPT
 {
     if (this == &__rhs)
       return;
-    if (__h && __rhs.__h) {
+    if (__h_ && __rhs.__h_) {
         any __tmp;
         __rhs.__call(_Action::_Move, &__tmp);
         this->__call(_Action::_Move, &__rhs);
         __tmp.__call(_Action::_Move, this);
     }
-    else if (__h) {
+    else if (__h_) {
         this->__call(_Action::_Move, &__rhs);
     }
-    else if (__rhs.__h) {
+    else if (__rhs.__h_) {
         __rhs.__call(_Action::_Move, this);
     }
 }
 
 // 6.4 Non-member functions
 
 inline _LIBCPP_INLINE_VISIBILITY
 void swap(any & __lhs, any & __rhs) _NOEXCEPT

 _LIBCPP_HIDE_FROM_ABI
 add_pointer_t<_ValueType>
 any_cast(any * __any) _NOEXCEPT
 {
     using __any_imp::_Action;
     static_assert(!is_reference<_ValueType>::value,
                   "_ValueType may not be a reference.");
     typedef typename add_pointer<_ValueType>::type _ReturnType;
-    if (__any && __any->__h) {
+    if (__any && __any->__h_) {
       void *__p = __any->__call(_Action::_Get, nullptr,
 #if !defined(_LIBCPP_NO_RTTI)
                           &typeid(_ValueType),
 #else
                           nullptr,
 #endif
                           __any_imp::__get_fallback_typeid<_ValueType>());
         return _VSTD::__pointer_or_func_cast<_ReturnType>(

libcxx/include/barrier

public:
     }
 };
 
 #endif // !_LIBCPP_HAS_NO_TREE_BARRIER
 
 template<class _CompletionF = __empty_completion>
 class barrier {
 
-    __barrier_base<_CompletionF> __b;
+    __barrier_base<_CompletionF> __b_;
 public:
     using arrival_token = typename __barrier_base<_CompletionF>::arrival_token;
 
     static constexpr ptrdiff_t max() noexcept {
         return __barrier_base<_CompletionF>::max();
     }
 
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     barrier(ptrdiff_t __count, _CompletionF __completion = _CompletionF())
-        : __b(__count, _VSTD::move(__completion)) {
+        : __b_(__count, _VSTD::move(__completion)) {
     }
 
     barrier(barrier const&) = delete;
     barrier& operator=(barrier const&) = delete;
 
     [[nodiscard]] _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     arrival_token arrive(ptrdiff_t __update = 1)
     {
-        return __b.arrive(__update);
+        return __b_.arrive(__update);
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void wait(arrival_token&& __phase) const
     {
-        __b.wait(_VSTD::move(__phase));
+        __b_.wait(_VSTD::move(__phase));
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void arrive_and_wait()
     {
         wait(arrive());
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void arrive_and_drop()
     {
-        __b.arrive_and_drop();
+        __b_.arrive_and_drop();
     }
 };
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // _LIBCPP_STD_VER >= 14
 
 _LIBCPP_POP_MACROS
 
 #endif //_LIBCPP_BARRIER

libcxx/include/codecvt

 
 template <class _Elem> class __codecvt_utf8;
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf8<wchar_t>
     : public codecvt<wchar_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
+    unsigned long __maxcode_;
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
-    codecvt_mode _Mode_;
+    codecvt_mode __mode_;
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 public:
     typedef wchar_t   intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf8(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<wchar_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
         do_in(state_type& __st,

 };
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf8<char16_t>
     : public codecvt<char16_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char16_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf8(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char16_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
protected:
     virtual int do_max_length() const _NOEXCEPT;
 };
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf8<char32_t>
     : public codecvt<char32_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char32_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf8(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char32_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result

 
 template <class _Elem, bool _LittleEndian> class __codecvt_utf16;
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf16<wchar_t, false>
     : public codecvt<wchar_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
+    unsigned long __maxcode_;
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
-    codecvt_mode _Mode_;
+    codecvt_mode __mode_;
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 public:
     typedef wchar_t   intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<wchar_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
         do_in(state_type& __st,
               const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
               intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
     virtual result
         do_unshift(state_type& __st,
                    extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual int do_encoding() const _NOEXCEPT;
     virtual bool do_always_noconv() const _NOEXCEPT;
     virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
                           size_t __mx) const;
     virtual int do_max_length() const _NOEXCEPT;
 };
 
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf16<wchar_t, true>
     : public codecvt<wchar_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
+    unsigned long __maxcode_;
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
-    codecvt_mode _Mode_;
+    codecvt_mode __mode_;
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 public:
     typedef wchar_t   intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<wchar_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
         do_in(state_type& __st,

 };
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf16<char16_t, false>
     : public codecvt<char16_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char16_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char16_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
protected:
     virtual int do_max_length() const _NOEXCEPT;
 };
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf16<char16_t, true>
     : public codecvt<char16_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char16_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char16_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
protected:
     virtual int do_max_length() const _NOEXCEPT;
 };
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf16<char32_t, false>
     : public codecvt<char32_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char32_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char32_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
protected:
     virtual int do_max_length() const _NOEXCEPT;
 };
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf16<char32_t, true>
     : public codecvt<char32_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char32_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char32_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result

 
 template <class _Elem> class __codecvt_utf8_utf16;
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<wchar_t>
     : public codecvt<wchar_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
+    unsigned long __maxcode_;
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
-    codecvt_mode _Mode_;
+    codecvt_mode __mode_;
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 public:
     typedef wchar_t   intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf8_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<wchar_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
         do_in(state_type& __st,

 };
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<char32_t>
     : public codecvt<char32_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char32_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf8_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char32_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result
protected:
     virtual int do_max_length() const _NOEXCEPT;
 };
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 template <>
 class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<char16_t>
     : public codecvt<char16_t, char, mbstate_t>
 {
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
+    unsigned long __maxcode_;
+    codecvt_mode __mode_;
 public:
     typedef char16_t  intern_type;
     typedef char      extern_type;
     typedef mbstate_t state_type;
 
     _LIBCPP_INLINE_VISIBILITY
     explicit __codecvt_utf8_utf16(size_t __refs, unsigned long __maxcode,
                             codecvt_mode __mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(__maxcode),
-          _Mode_(__mode) {}
+        : codecvt<char16_t, char, mbstate_t>(__refs), __maxcode_(__maxcode),
+          __mode_(__mode) {}
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 protected:
     virtual result
         do_out(state_type& __st,
                const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
                extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
     virtual result

libcxx/include/experimental/functional

 
 //  General case for BM data searching; use a map
 template<class _Key, typename _Value, class _Hash, class _BinaryPredicate>
 class _BMSkipTable<_Key, _Value, _Hash, _BinaryPredicate, false> {
     typedef _Value value_type;
     typedef _Key   key_type;
 
     const _Value __default_value_;
-    std::unordered_map<_Key, _Value, _Hash, _BinaryPredicate> __table;
+    std::unordered_map<_Key, _Value, _Hash, _BinaryPredicate> __table_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
     _BMSkipTable(size_t __sz, _Value __default, _Hash __hf, _BinaryPredicate __pred)
-        : __default_value_(__default), __table(__sz, __hf, __pred) {}
+        : __default_value_(__default), __table_(__sz, __hf, __pred) {}
 
     _LIBCPP_INLINE_VISIBILITY
     void insert(const key_type &__key, value_type __val)
     {
-        __table [__key] = __val;    // Would skip_.insert (val) be better here?
+        __table_ [__key] = __val;    // Would skip_.insert (val) be better here?
     }
 
     _LIBCPP_INLINE_VISIBILITY
     value_type operator [](const key_type & __key) const
     {
-        auto __it = __table.find (__key);
-        return __it == __table.end() ? __default_value_ : __it->second;
+        auto __it = __table_.find (__key);
+        return __it == __table_.end() ? __default_value_ : __it->second;
     }
 };
 
 
 //  Special case small numeric values; use an array
 template<class _Key, typename _Value, class _Hash, class _BinaryPredicate>
 class _BMSkipTable<_Key, _Value, _Hash, _BinaryPredicate, true> {
 private:
     typedef _Value value_type;
     typedef _Key   key_type;
 
     typedef typename make_unsigned<key_type>::type unsigned_key_type;
     typedef std::array<value_type, 256> skip_map;
-    skip_map __table;
+    skip_map __table_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
     _BMSkipTable(size_t /*__sz*/, _Value __default, _Hash /*__hf*/, _BinaryPredicate /*__pred*/)
     {
-        std::fill_n(__table.begin(), __table.size(), __default);
+        std::fill_n(__table_.begin(), __table_.size(), __default);
     }
 
     _LIBCPP_INLINE_VISIBILITY
     void insert(key_type __key, value_type __val)
     {
-        __table[static_cast<unsigned_key_type>(__key)] = __val;
+        __table_[static_cast<unsigned_key_type>(__key)] = __val;
     }
 
     _LIBCPP_INLINE_VISIBILITY
     value_type operator [](key_type __key) const
     {
-        return __table[static_cast<unsigned_key_type>(__key)];
+        return __table_[static_cast<unsigned_key_type>(__key)];
     }
 };
 
 
 template <class _RandomAccessIterator1,
           class _Hash = hash<typename iterator_traits<_RandomAccessIterator1>::value_type>,
           class _BinaryPredicate = equal_to<>>
 class _LIBCPP_DEPRECATED_BOYER_MOORE_SEARCHER _LIBCPP_TEMPLATE_VIS boyer_moore_searcher {

libcxx/include/experimental/iterator

public:
     typedef basic_ostream<char_type,traits_type> ostream_type;
     typedef output_iterator_tag                  iterator_category;
     typedef void                                 value_type;
     typedef void                                 difference_type;
     typedef void                                 pointer;
     typedef void                                 reference;
 
     ostream_joiner(ostream_type& __os, _Delim&& __d)
-        : __output_iter(_VSTD::addressof(__os)), __delim(_VSTD::move(__d)), __first(true) {}
+        : __output_iter_(_VSTD::addressof(__os)), __delim_(_VSTD::move(__d)), __first_(true) {}
 
     ostream_joiner(ostream_type& __os, const _Delim& __d)
-        : __output_iter(_VSTD::addressof(__os)), __delim(__d), __first(true) {}
+        : __output_iter_(_VSTD::addressof(__os)), __delim_(__d), __first_(true) {}
 
 
     template<typename _Tp>
     ostream_joiner& operator=(const _Tp& __v)
     {
-        if (!__first)
-            *__output_iter << __delim;
-        __first = false;
-        *__output_iter << __v;
+        if (!__first_)
+            *__output_iter_ << __delim_;
+        __first_ = false;
+        *__output_iter_ << __v;
         return *this;
     }
 
     ostream_joiner& operator*()     _NOEXCEPT { return *this; }
     ostream_joiner& operator++()    _NOEXCEPT { return *this; }
     ostream_joiner& operator++(int) _NOEXCEPT { return *this; }
 
 private:
-    ostream_type*   __output_iter;
-    _Delim          __delim;
-    bool            __first;
+    ostream_type*   __output_iter_;
+    _Delim          __delim_;
+    bool            __first_;
 };
 
 
 template <class _CharT, class _Traits, class _Delim>
 ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>
 make_ostream_joiner(basic_ostream<_CharT, _Traits>& __os, _Delim && __d)
 { return ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>(__os, _VSTD::forward<_Delim>(__d)); }
 
 _LIBCPP_END_NAMESPACE_LFTS
 
 #endif // _LIBCPP_STD_VER > 11
 
 #endif // _LIBCPP_EXPERIMENTAL_ITERATOR

libcxx/include/latch

 #include <__undef_macros>
 
 #if _LIBCPP_STD_VER >= 14
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class latch
 {
-    __atomic_base<ptrdiff_t> __a;
+    __atomic_base<ptrdiff_t> __a_;
 
 public:
     static constexpr ptrdiff_t max() noexcept {
         return numeric_limits<ptrdiff_t>::max();
     }
 
     inline _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit latch(ptrdiff_t __expected) : __a(__expected) { }
+    constexpr explicit latch(ptrdiff_t __expected) : __a_(__expected) { }
 
     ~latch() = default;
     latch(const latch&) = delete;
     latch& operator=(const latch&) = delete;
 
     inline _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void count_down(ptrdiff_t __update = 1)
     {
-        auto const __old = __a.fetch_sub(__update, memory_order_release);
+        auto const __old = __a_.fetch_sub(__update, memory_order_release);
         if(__old == __update)
-            __a.notify_all();
+            __a_.notify_all();
     }
     inline _LIBCPP_INLINE_VISIBILITY
     bool try_wait() const noexcept
     {
-        return 0 == __a.load(memory_order_acquire);
+        return 0 == __a_.load(memory_order_acquire);
     }
     inline _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void wait() const
     {
-        __cxx_atomic_wait(&__a.__a_, [&]() -> bool {
+        __cxx_atomic_wait(&__a_.__a_, [&]() -> bool {
             return try_wait();
         });
     }
     inline _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void arrive_and_wait(ptrdiff_t __update = 1)
     {
         count_down(__update);
         wait();

libcxx/include/map

#if _LIBCPP_STD_VER > 11
     bool operator()(const _CP& __x, const _K2& __y) const
         {return static_cast<const _Compare&>(*this)(__x.__get_value().first, __y);}
 #endif
 };
 
 template <class _Key, class _CP, class _Compare>
 class __map_value_compare<_Key, _CP, _Compare, false>
 {
-    _Compare comp;
+    _Compare __comp_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
     __map_value_compare()
         _NOEXCEPT_(is_nothrow_default_constructible<_Compare>::value)
-        : comp() {}
+        : __comp_() {}
     _LIBCPP_INLINE_VISIBILITY
     __map_value_compare(_Compare __c)
         _NOEXCEPT_(is_nothrow_copy_constructible<_Compare>::value)
-        : comp(__c) {}
+        : __comp_(__c) {}
     _LIBCPP_INLINE_VISIBILITY
-    const _Compare& key_comp() const _NOEXCEPT {return comp;}
+    const _Compare& key_comp() const _NOEXCEPT {return __comp_;}
 
     _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _CP& __x, const _CP& __y) const
-        {return comp(__x.__get_value().first, __y.__get_value().first);}
+        {return __comp_(__x.__get_value().first, __y.__get_value().first);}
     _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _CP& __x, const _Key& __y) const
-        {return comp(__x.__get_value().first, __y);}
+        {return __comp_(__x.__get_value().first, __y);}
     _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _Key& __x, const _CP& __y) const
-        {return comp(__x, __y.__get_value().first);}
+        {return __comp_(__x, __y.__get_value().first);}
     void swap(__map_value_compare& __y)
         _NOEXCEPT_(__is_nothrow_swappable<_Compare>::value)
     {
         using _VSTD::swap;
-        swap(comp, __y.comp);
+        swap(__comp_, __y.__comp_);
     }
 
 #if _LIBCPP_STD_VER > 11
     template <typename _K2>
     _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _K2& __x, const _CP& __y) const
-        {return comp(__x, __y.__get_value().first);}
+        {return __comp_(__x, __y.__get_value().first);}
 
     template <typename _K2>
     _LIBCPP_INLINE_VISIBILITY
     bool operator()(const _CP& __x, const _K2& __y) const
-        {return comp(__x.__get_value().first, __y);}
+        {return __comp_(__x.__get_value().first, __y);}
 #endif
 };
 
 template <class _Key, class _CP, class _Compare, bool __b>
 inline _LIBCPP_INLINE_VISIBILITY
 void
 swap(__map_value_compare<_Key, _CP, _Compare, __b>& __x,
      __map_value_compare<_Key, _CP, _Compare, __b>& __y)

 {
     typedef _Key                                     key_type;
     typedef _Tp                                      mapped_type;
     typedef pair<const key_type, mapped_type>        value_type;
     typedef pair<key_type&, mapped_type&>            __nc_ref_pair_type;
     typedef pair<key_type&&, mapped_type&&>          __nc_rref_pair_type;
 
 private:
-    value_type __cc;
+    value_type __cc_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
     value_type& __get_value()
     {
 #if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
+        return *_VSTD::launder(_VSTD::addressof(__cc_));
 #else
         return __cc;
 #endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
     const value_type& __get_value() const
     {
 #if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
+        return *_VSTD::launder(_VSTD::addressof(__cc_));
 #else
         return __cc;
 #endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
     __nc_ref_pair_type __ref()
     {

libcxx/include/semaphore

 __atomic_semaphore_base is the general-case implementation.
 It is a typical Dijkstra semaphore algorithm over atomics, wait and notify
 functions. It avoids contention against users' own use of those facilities.
 
 */
 
 class __atomic_semaphore_base
 {
-    __atomic_base<ptrdiff_t> __a;
+    __atomic_base<ptrdiff_t> __a_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit __atomic_semaphore_base(ptrdiff_t __count) : __a(__count)
+    constexpr explicit __atomic_semaphore_base(ptrdiff_t __count) : __a_(__count)
     {
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void release(ptrdiff_t __update = 1)
     {
-        if(0 < __a.fetch_add(__update, memory_order_release))
+        if(0 < __a_.fetch_add(__update, memory_order_release))
             ;
         else if(__update > 1)
-            __a.notify_all();
+            __a_.notify_all();
         else
-            __a.notify_one();
+            __a_.notify_one();
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void acquire()
     {
         auto const __test_fn = [this]() -> bool {
-            auto __old = __a.load(memory_order_relaxed);
-            return (__old != 0) && __a.compare_exchange_strong(__old, __old - 1, memory_order_acquire, memory_order_relaxed);
+            auto __old = __a_.load(memory_order_relaxed);
+            return (__old != 0) && __a_.compare_exchange_strong(__old, __old - 1, memory_order_acquire, memory_order_relaxed);
         };
-        __cxx_atomic_wait(&__a.__a_, __test_fn);
+        __cxx_atomic_wait(&__a_.__a_, __test_fn);
     }
     template <class Rep, class Period>
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     bool try_acquire_for(chrono::duration<Rep, Period> const& __rel_time)
     {
         if (__rel_time == chrono::duration<Rep, Period>::zero())
             return try_acquire();
         auto const __test_fn = [this]() { return try_acquire(); };
         return __libcpp_thread_poll_with_backoff(__test_fn, __libcpp_timed_backoff_policy(), __rel_time);
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     bool try_acquire()
     {
-        auto __old = __a.load(memory_order_acquire);
+        auto __old = __a_.load(memory_order_acquire);
         while (true) {
             if (__old == 0)
                 return false;
-            if (__a.compare_exchange_strong(__old, __old - 1, memory_order_acquire, memory_order_relaxed))
+            if (__a_.compare_exchange_strong(__old, __old - 1, memory_order_acquire, memory_order_relaxed))
                 return true;
         }
     }
 };
 
 #define _LIBCPP_SEMAPHORE_MAX (numeric_limits<ptrdiff_t>::max())
 
 template<ptrdiff_t __least_max_value = _LIBCPP_SEMAPHORE_MAX>
 class counting_semaphore
 {
-    __atomic_semaphore_base __semaphore;
+    __atomic_semaphore_base __semaphore_;
 
 public:
     static constexpr ptrdiff_t max() noexcept {
         return __least_max_value;
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit counting_semaphore(ptrdiff_t __count) : __semaphore(__count) { }
+    constexpr explicit counting_semaphore(ptrdiff_t __count) : __semaphore_(__count) { }
     ~counting_semaphore() = default;
 
     counting_semaphore(const counting_semaphore&) = delete;
     counting_semaphore& operator=(const counting_semaphore&) = delete;
 
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void release(ptrdiff_t __update = 1)
     {
-        __semaphore.release(__update);
+        __semaphore_.release(__update);
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     void acquire()
     {
-        __semaphore.acquire();
+        __semaphore_.acquire();
     }
     template<class Rep, class Period>
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     bool try_acquire_for(chrono::duration<Rep, Period> const& __rel_time)
     {
-        return __semaphore.try_acquire_for(chrono::duration_cast<chrono::nanoseconds>(__rel_time));
+        return __semaphore_.try_acquire_for(chrono::duration_cast<chrono::nanoseconds>(__rel_time));
     }
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     bool try_acquire()
     {
-        return __semaphore.try_acquire();
+        return __semaphore_.try_acquire();
     }
     template <class Clock, class Duration>
     _LIBCPP_AVAILABILITY_SYNC _LIBCPP_INLINE_VISIBILITY
     bool try_acquire_until(chrono::time_point<Clock, Duration> const& __abs_time)
     {
         auto const current = Clock::now();
         if (current >= __abs_time)
             return try_acquire();

libcxx/include/shared_mutex

 //     typedef implementation-defined native_handle_type; // See 30.2.3
 //     native_handle_type native_handle(); // See 30.2.3
 };
 
 
 #if _LIBCPP_STD_VER > 14
 class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_SHARED_MUTEX shared_mutex
 {
-    __shared_mutex_base __base;
+    __shared_mutex_base __base_;
 public:
-    _LIBCPP_INLINE_VISIBILITY shared_mutex() : __base() {}
+    _LIBCPP_INLINE_VISIBILITY shared_mutex() : __base_() {}
     _LIBCPP_INLINE_VISIBILITY ~shared_mutex() = default;
 
     shared_mutex(const shared_mutex&) = delete;
     shared_mutex& operator=(const shared_mutex&) = delete;
 
     // Exclusive ownership
-    _LIBCPP_INLINE_VISIBILITY void lock()     { return __base.lock(); }
-    _LIBCPP_INLINE_VISIBILITY bool try_lock() { return __base.try_lock(); }
-    _LIBCPP_INLINE_VISIBILITY void unlock()   { return __base.unlock(); }
+    _LIBCPP_INLINE_VISIBILITY void lock()     { return __base_.lock(); }
+    _LIBCPP_INLINE_VISIBILITY bool try_lock() { return __base_.try_lock(); }
+    _LIBCPP_INLINE_VISIBILITY void unlock()   { return __base_.unlock(); }
 
     // Shared ownership
-    _LIBCPP_INLINE_VISIBILITY void lock_shared()     { return __base.lock_shared(); }
-    _LIBCPP_INLINE_VISIBILITY bool try_lock_shared() { return __base.try_lock_shared(); }
-    _LIBCPP_INLINE_VISIBILITY void unlock_shared()   { return __base.unlock_shared(); }
+    _LIBCPP_INLINE_VISIBILITY void lock_shared()     { return __base_.lock_shared(); }
+    _LIBCPP_INLINE_VISIBILITY bool try_lock_shared() { return __base_.try_lock_shared(); }
+    _LIBCPP_INLINE_VISIBILITY void unlock_shared()   { return __base_.unlock_shared(); }
 
 //     typedef __shared_mutex_base::native_handle_type native_handle_type;
 //     _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() { return __base::unlock_shared(); }
 };
 #endif
 
 
 class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_SHARED_MUTEX shared_timed_mutex
 {
-    __shared_mutex_base __base;
+    __shared_mutex_base __base_;
 public:
     shared_timed_mutex();
     _LIBCPP_INLINE_VISIBILITY ~shared_timed_mutex() = default;
 
     shared_timed_mutex(const shared_timed_mutex&) = delete;
     shared_timed_mutex& operator=(const shared_timed_mutex&) = delete;
 
     // Exclusive ownership
public:
     void unlock_shared();
 };
 
 template <class _Clock, class _Duration>
 bool
 shared_timed_mutex::try_lock_until(
                         const chrono::time_point<_Clock, _Duration>& __abs_time)
 {
-    unique_lock<mutex> __lk(__base.__mut_);
-    if (__base.__state_ & __base.__write_entered_)
+    unique_lock<mutex> __lk(__base_.__mut_);
+    if (__base_.__state_ & __base_.__write_entered_)
     {
         while (true)
         {
-            cv_status __status = __base.__gate1_.wait_until(__lk, __abs_time);
-            if ((__base.__state_ & __base.__write_entered_) == 0)
+            cv_status __status = __base_.__gate1_.wait_until(__lk, __abs_time);
+            if ((__base_.__state_ & __base_.__write_entered_) == 0)
                 break;
             if (__status == cv_status::timeout)
                 return false;
         }
     }
-    __base.__state_ |= __base.__write_entered_;
-    if (__base.__state_ & __base.__n_readers_)
+    __base_.__state_ |= __base_.__write_entered_;
+    if (__base_.__state_ & __base_.__n_readers_)
     {
         while (true)
         {
-            cv_status __status = __base.__gate2_.wait_until(__lk, __abs_time);
-            if ((__base.__state_ & __base.__n_readers_) == 0)
+            cv_status __status = __base_.__gate2_.wait_until(__lk, __abs_time);
+            if ((__base_.__state_ & __base_.__n_readers_) == 0)
                 break;
             if (__status == cv_status::timeout)
             {
-                __base.__state_ &= ~__base.__write_entered_;
-                __base.__gate1_.notify_all();
+                __base_.__state_ &= ~__base_.__write_entered_;
+                __base_.__gate1_.notify_all();
                 return false;
             }
         }
     }
     return true;
 }
 
 template <class _Clock, class _Duration>
 bool
 shared_timed_mutex::try_lock_shared_until(
                         const chrono::time_point<_Clock, _Duration>& __abs_time)
 {
-    unique_lock<mutex> __lk(__base.__mut_);
-    if ((__base.__state_ & __base.__write_entered_) || (__base.__state_ & __base.__n_readers_) == __base.__n_readers_)
+    unique_lock<mutex> __lk(__base_.__mut_);
+    if ((__base_.__state_ & __base_.__write_entered_) || (__base_.__state_ & __base_.__n_readers_) == __base_.__n_readers_)
     {
         while (true)
         {
-            cv_status status = __base.__gate1_.wait_until(__lk, __abs_time);
-            if ((__base.__state_ & __base.__write_entered_) == 0 &&
-                                       (__base.__state_ & __base.__n_readers_) < __base.__n_readers_)
+            cv_status status = __base_.__gate1_.wait_until(__lk, __abs_time);
+            if ((__base_.__state_ & __base_.__write_entered_) == 0 &&
+                                       (__base_.__state_ & __base_.__n_readers_) < __base_.__n_readers_)
                 break;
             if (status == cv_status::timeout)
                 return false;
         }
     }
-    unsigned __num_readers = (__base.__state_ & __base.__n_readers_) + 1;
-    __base.__state_ &= ~__base.__n_readers_;
-    __base.__state_ |= __num_readers;
+    unsigned __num_readers = (__base_.__state_ & __base_.__n_readers_) + 1;
+    __base_.__state_ &= ~__base_.__n_readers_;
+    __base_.__state_ |= __num_readers;
     return true;
 }
 
 template <class _Mutex>
 class shared_lock
 {
 public:
     typedef _Mutex mutex_type;

libcxx/include/span

#else
     using iterator               = __wrap_iter<pointer>;
 #endif
     using reverse_iterator       = _VSTD::reverse_iterator<iterator>;
 
     static constexpr size_type extent = _Extent;
 
 // [span.cons], span constructors, copy, assignment, and destructor
     template <size_t _Sz = _Extent> requires(_Sz == 0)
-    _LIBCPP_INLINE_VISIBILITY constexpr span() noexcept : __data{nullptr} {}
+    _LIBCPP_INLINE_VISIBILITY constexpr span() noexcept : __data_{nullptr} {}
 
     constexpr span           (const span&) noexcept = default;
     constexpr span& operator=(const span&) noexcept = default;
 
     template <__span_compatible_iterator<element_type> _It>
     _LIBCPP_INLINE_VISIBILITY
     constexpr explicit span(_It __first, size_type __count)
-        : __data{_VSTD::to_address(__first)} {
+        : __data_{_VSTD::to_address(__first)} {
       (void)__count;
       _LIBCPP_ASSERT(_Extent == __count, "size mismatch in span's constructor (iterator, len)");
     }
 
     template <__span_compatible_iterator<element_type> _It, __span_compatible_sentinel_for<_It> _End>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit span(_It __first, _End __last) : __data{_VSTD::to_address(__first)} {
+    constexpr explicit span(_It __first, _End __last) : __data_{_VSTD::to_address(__first)} {
       (void)__last;
       _LIBCPP_ASSERT((__last - __first >= 0), "invalid range in span's constructor (iterator, sentinel)");
       _LIBCPP_ASSERT(__last - __first == _Extent,
                      "invalid range in span's constructor (iterator, sentinel): last - first != extent");
     }
 
-    _LIBCPP_INLINE_VISIBILITY constexpr span(type_identity_t<element_type> (&__arr)[_Extent]) noexcept : __data{__arr} {}
+    _LIBCPP_INLINE_VISIBILITY constexpr span(type_identity_t<element_type> (&__arr)[_Extent]) noexcept : __data_{__arr} {}
 
     template <__span_array_convertible<element_type> _OtherElementType>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr span(array<_OtherElementType, _Extent>& __arr) noexcept : __data{__arr.data()} {}
+    constexpr span(array<_OtherElementType, _Extent>& __arr) noexcept : __data_{__arr.data()} {}
 
     template <class _OtherElementType>
         requires __span_array_convertible<const _OtherElementType, element_type>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr span(const array<_OtherElementType, _Extent>& __arr) noexcept : __data{__arr.data()} {}
+    constexpr span(const array<_OtherElementType, _Extent>& __arr) noexcept : __data_{__arr.data()} {}
 
 #if defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <class _Container>
         requires __span_compatible_range<_Container, element_type>
     _LIBCPP_INLINE_VISIBILITY
     constexpr explicit span(_Container& __c) : __data{std::data(__c)} {
       _LIBCPP_ASSERT(std::size(__c) == _Extent, "size mismatch in span's constructor (range)");
     }
     template <class _Container>
         requires __span_compatible_range<const _Container, element_type>
     _LIBCPP_INLINE_VISIBILITY
     constexpr explicit span(const _Container& __c) : __data{std::data(__c)} {
       _LIBCPP_ASSERT(std::size(__c) == _Extent, "size mismatch in span's constructor (range)");
     }
 #else
     template <__span_compatible_range<element_type> _Range>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit span(_Range&& __r) : __data{ranges::data(__r)} {
+    constexpr explicit span(_Range&& __r) : __data_{ranges::data(__r)} {
       _LIBCPP_ASSERT(ranges::size(__r) == _Extent, "size mismatch in span's constructor (range)");
     }
 #endif
 
     template <__span_array_convertible<element_type> _OtherElementType>
     _LIBCPP_INLINE_VISIBILITY
         constexpr span(const span<_OtherElementType, _Extent>& __other)
-        : __data{__other.data()} {}
+        : __data_{__other.data()} {}
 
     template <__span_array_convertible<element_type> _OtherElementType>
     _LIBCPP_INLINE_VISIBILITY
         constexpr explicit span(const span<_OtherElementType, dynamic_extent>& __other) noexcept
-        : __data{__other.data()} { _LIBCPP_ASSERT(_Extent == __other.size(), "size mismatch in span's constructor (other span)"); }
+        : __data_{__other.data()} { _LIBCPP_ASSERT(_Extent == __other.size(), "size mismatch in span's constructor (other span)"); }
 
 
 //  ~span() noexcept = default;
 
     template <size_t _Count>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span<element_type, _Count> first() const noexcept
     {
//  ~span() noexcept = default;
 
     _LIBCPP_INLINE_VISIBILITY constexpr size_type size()           const noexcept { return _Extent; }
     _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes()     const noexcept { return _Extent * sizeof(element_type); }
     [[nodiscard]] _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return _Extent == 0; }
 
     _LIBCPP_INLINE_VISIBILITY constexpr reference operator[](size_type __idx) const noexcept
     {
         _LIBCPP_ASSERT(__idx < size(), "span<T, N>::operator[](index): index out of range");
-        return __data[__idx];
+        return __data_[__idx];
     }
 
     _LIBCPP_INLINE_VISIBILITY constexpr reference front() const noexcept
     {
         _LIBCPP_ASSERT(!empty(), "span<T, N>::front() on empty span");
-        return __data[0];
+        return __data_[0];
     }
 
     _LIBCPP_INLINE_VISIBILITY constexpr reference back() const noexcept
     {
         _LIBCPP_ASSERT(!empty(), "span<T, N>::back() on empty span");
-        return __data[size()-1];
+        return __data_[size()-1];
     }
 
-    _LIBCPP_INLINE_VISIBILITY constexpr pointer data()                         const noexcept { return __data; }
+    _LIBCPP_INLINE_VISIBILITY constexpr pointer data()                         const noexcept { return __data_; }
 
 // [span.iter], span iterator support
     _LIBCPP_INLINE_VISIBILITY constexpr iterator begin() const noexcept {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
         return std::__make_bounded_iter(data(), data(), data() + size());
 #else
         return iterator(this, data());
 #endif
#endif
 
     _LIBCPP_INLINE_VISIBILITY span<const byte, _Extent * sizeof(element_type)> __as_bytes() const noexcept
     { return span<const byte, _Extent * sizeof(element_type)>{reinterpret_cast<const byte *>(data()), size_bytes()}; }
 
     _LIBCPP_INLINE_VISIBILITY span<byte, _Extent * sizeof(element_type)> __as_writable_bytes() const noexcept
     { return span<byte, _Extent * sizeof(element_type)>{reinterpret_cast<byte *>(data()), size_bytes()}; }
 
 private:
-    pointer    __data;
+    pointer    __data_;
 };
 
 
 template <typename _Tp>
 class _LIBCPP_TEMPLATE_VIS span<_Tp, dynamic_extent> {
 public:
 //  constants and types
     using element_type           = _Tp;

 #else
     using iterator               = __wrap_iter<pointer>;
 #endif
     using reverse_iterator       = _VSTD::reverse_iterator<iterator>;
 
     static constexpr size_type extent = dynamic_extent;
 
 // [span.cons], span constructors, copy, assignment, and destructor
-    _LIBCPP_INLINE_VISIBILITY constexpr span() noexcept : __data{nullptr}, __size{0} {}
+    _LIBCPP_INLINE_VISIBILITY constexpr span() noexcept : __data_{nullptr}, __size_{0} {}
 
     constexpr span           (const span&) noexcept = default;
     constexpr span& operator=(const span&) noexcept = default;
 
     template <__span_compatible_iterator<element_type> _It>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(_It __first, size_type __count)
-        : __data{_VSTD::to_address(__first)}, __size{__count} {}
+        : __data_{_VSTD::to_address(__first)}, __size_{__count} {}
 
     template <__span_compatible_iterator<element_type> _It, __span_compatible_sentinel_for<_It> _End>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(_It __first, _End __last)
-        : __data(_VSTD::to_address(__first)), __size(__last - __first) {}
+        : __data_(_VSTD::to_address(__first)), __size_(__last - __first) {}
 
     template <size_t _Sz>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr span(type_identity_t<element_type> (&__arr)[_Sz]) noexcept : __data{__arr}, __size{_Sz} {}
+    constexpr span(type_identity_t<element_type> (&__arr)[_Sz]) noexcept : __data_{__arr}, __size_{_Sz} {}
 
     template <__span_array_convertible<element_type> _OtherElementType, size_t _Sz>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr span(array<_OtherElementType, _Sz>& __arr) noexcept : __data{__arr.data()}, __size{_Sz} {}
+    constexpr span(array<_OtherElementType, _Sz>& __arr) noexcept : __data_{__arr.data()}, __size_{_Sz} {}
 
     template <class _OtherElementType, size_t _Sz>
         requires __span_array_convertible<const _OtherElementType, element_type>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr span(const array<_OtherElementType, _Sz>& __arr) noexcept : __data{__arr.data()}, __size{_Sz} {}
+    constexpr span(const array<_OtherElementType, _Sz>& __arr) noexcept : __data_{__arr.data()}, __size_{_Sz} {}
 
 #if defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <class _Container>
         requires __span_compatible_range<_Container, element_type>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(_Container& __c) : __data(std::data(__c)), __size{std::size(__c)} {}
     template <class _Container>
         requires __span_compatible_range<const _Container, element_type>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(const _Container& __c) : __data(std::data(__c)), __size{std::size(__c)} {}
 #else
     template <__span_compatible_range<element_type> _Range>
     _LIBCPP_INLINE_VISIBILITY
-    constexpr span(_Range&& __r) : __data(ranges::data(__r)), __size{ranges::size(__r)} {}
+    constexpr span(_Range&& __r) : __data_(ranges::data(__r)), __size_{ranges::size(__r)} {}
 #endif
 
     template <__span_array_convertible<element_type> _OtherElementType, size_t _OtherExtent>
     _LIBCPP_INLINE_VISIBILITY
         constexpr span(const span<_OtherElementType, _OtherExtent>& __other)  noexcept
-        : __data{__other.data()}, __size{__other.size()} {}
+        : __data_{__other.data()}, __size_{__other.size()} {}
 
 //    ~span() noexcept = default;
 
     template <size_t _Count>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span<element_type, _Count> first() const noexcept
     {
         _LIBCPP_ASSERT(_Count <= size(), "span<T>::first<Count>(): Count out of range");
subspan(size_type __offset, size_type __count = dynamic_extent) const noexcept
         _LIBCPP_ASSERT(__offset <= size(), "span<T>::subspan(offset, count): offset out of range");
         _LIBCPP_ASSERT(__count <= size() || __count == dynamic_extent, "span<T>::subspan(offset, count): count out of range");
         if (__count == dynamic_extent)
             return {data() + __offset, size() - __offset};
         _LIBCPP_ASSERT(__count <= size() - __offset, "span<T>::subspan(offset, count): offset + count out of range");
         return {data() + __offset, __count};
     }
 
-    _LIBCPP_INLINE_VISIBILITY constexpr size_type size()           const noexcept { return __size; }
-    _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes()     const noexcept { return __size * sizeof(element_type); }
-    [[nodiscard]] _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return __size == 0; }
+    _LIBCPP_INLINE_VISIBILITY constexpr size_type size()           const noexcept { return __size_; }
+    _LIBCPP_INLINE_VISIBILITY constexpr size_type size_bytes()     const noexcept { return __size_ * sizeof(element_type); }
+    [[nodiscard]] _LIBCPP_INLINE_VISIBILITY constexpr bool empty() const noexcept { return __size_ == 0; }
 
     _LIBCPP_INLINE_VISIBILITY constexpr reference operator[](size_type __idx) const noexcept
     {
         _LIBCPP_ASSERT(__idx < size(), "span<T>::operator[](index): index out of range");
-        return __data[__idx];
+        return __data_[__idx];
     }
 
     _LIBCPP_INLINE_VISIBILITY constexpr reference front() const noexcept
     {
         _LIBCPP_ASSERT(!empty(), "span<T>::front() on empty span");
-        return __data[0];
+        return __data_[0];
     }
 
     _LIBCPP_INLINE_VISIBILITY constexpr reference back() const noexcept
     {
         _LIBCPP_ASSERT(!empty(), "span<T>::back() on empty span");
-        return __data[size()-1];
+        return __data_[size()-1];
     }
 
 
-    _LIBCPP_INLINE_VISIBILITY constexpr pointer data()                         const noexcept { return __data; }
+    _LIBCPP_INLINE_VISIBILITY constexpr pointer data()                         const noexcept { return __data_; }
 
 // [span.iter], span iterator support
     _LIBCPP_INLINE_VISIBILITY constexpr iterator begin() const noexcept {
 #ifdef _LIBCPP_ENABLE_DEBUG_MODE
         return std::__make_bounded_iter(data(), data(), data() + size());
 #else
         return iterator(this, data());
 #endif
#endif
 
     _LIBCPP_INLINE_VISIBILITY span<const byte, dynamic_extent> __as_bytes() const noexcept
     { return {reinterpret_cast<const byte *>(data()), size_bytes()}; }
 
     _LIBCPP_INLINE_VISIBILITY span<byte, dynamic_extent> __as_writable_bytes() const noexcept
     { return {reinterpret_cast<byte *>(data()), size_bytes()}; }
 
 private:
-    pointer   __data;
-    size_type __size;
+    pointer   __data_;
+    size_type __size_;
 };
 
 template <class _Tp, size_t _Extent>
 inline constexpr bool ranges::enable_borrowed_range<span<_Tp, _Extent> > = true;
 
 template <class _ElementType, size_t _Extent>
 inline constexpr bool ranges::enable_view<span<_ElementType, _Extent>> = true;
 

libcxx/include/string_view

public:
     static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
     static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
     static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
     static_assert((is_same<_CharT, typename traits_type::char_type>::value),
                   "traits_type::char_type must be the same type as CharT");
 
     // [string.view.cons], construct/copy
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
+    basic_string_view() _NOEXCEPT : __data_ (nullptr), __size_(0) {}
 
     _LIBCPP_INLINE_VISIBILITY
     basic_string_view(const basic_string_view&) _NOEXCEPT = default;
 
     _LIBCPP_INLINE_VISIBILITY
     basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
-        : __data(__s), __size(__len)
+        : __data_(__s), __size_(__len)
     {
 #if _LIBCPP_STD_VER > 11
     _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
 #endif
     }
 
 #if _LIBCPP_STD_VER > 17
     template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
       requires (is_same_v<iter_value_t<_It>, _CharT> && !is_convertible_v<_End, size_type>)
     constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
-       : __data(_VSTD::to_address(__begin)), __size(__end - __begin)
+       : __data_(_VSTD::to_address(__begin)), __size_(__end - __begin)
     {
       _LIBCPP_ASSERT((__end - __begin) >= 0, "std::string_view::string_view(iterator, sentinel) received invalid range");
     }
 #endif // _LIBCPP_STD_VER > 17
 
 #if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <class _Range>
       requires (
         !is_same_v<remove_cvref_t<_Range>, basic_string_view> &&
         ranges::contiguous_range<_Range> &&
         ranges::sized_range<_Range> &&
         is_same_v<ranges::range_value_t<_Range>, _CharT> &&
         !is_convertible_v<_Range, const _CharT*> &&
         (!requires(remove_cvref_t<_Range>& __d) {
           __d.operator _VSTD::basic_string_view<_CharT, _Traits>();
         }) &&
         (!requires {
          typename remove_reference_t<_Range>::traits_type;
         } || is_same_v<typename remove_reference_t<_Range>::traits_type, _Traits>)
       )
     constexpr _LIBCPP_HIDE_FROM_ABI
-    basic_string_view(_Range&& __r) : __data(ranges::data(__r)), __size(ranges::size(__r)) {}
+    basic_string_view(_Range&& __r) : __data_(ranges::data(__r)), __size_(ranges::size(__r)) {}
 #endif // _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     basic_string_view(const _CharT* __s)
-        : __data(__s), __size(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
+        : __data_(__s), __size_(_VSTD::__char_traits_length_checked<_Traits>(__s)) {}
 
 #if _LIBCPP_STD_VER > 20
     basic_string_view(nullptr_t) = delete;
 #endif
 
     // [string.view.iterators], iterators
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_iterator begin()  const _NOEXCEPT { return cbegin(); }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_iterator end()    const _NOEXCEPT { return cend(); }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT { return __data; }
+    const_iterator cbegin() const _NOEXCEPT { return __data_; }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
+    const_iterator cend()   const _NOEXCEPT { return __data_ + __size_; }
 
     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
 
     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
 
     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
 
     _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
     const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
 
     // [string.view.capacity], capacity
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    size_type size()     const _NOEXCEPT { return __size; }
+    size_type size()     const _NOEXCEPT { return __size_; }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    size_type length()   const _NOEXCEPT { return __size; }
+    size_type length()   const _NOEXCEPT { return __size_; }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max() / sizeof(value_type); }
 
     _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    bool empty()         const _NOEXCEPT { return __size == 0; }
+    bool empty()         const _NOEXCEPT { return __size_ == 0; }
 
     // [string.view.access], element access
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_reference operator[](size_type __pos) const _NOEXCEPT {
-      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data[__pos];
+      return _LIBCPP_ASSERT(__pos < size(), "string_view[] index out of bounds"), __data_[__pos];
     }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_reference at(size_type __pos) const
     {
         return __pos >= size()
-            ? (__throw_out_of_range("string_view::at"), __data[0])
-            : __data[__pos];
+            ? (__throw_out_of_range("string_view::at"), __data_[0])
+            : __data_[__pos];
     }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_reference front() const _NOEXCEPT
     {
-        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
+        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data_[0];
     }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
     const_reference back() const _NOEXCEPT
     {
-        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
+        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data_[__size_-1];
     }
 
     _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_pointer data() const _NOEXCEPT { return __data; }
+    const_pointer data() const _NOEXCEPT { return __data_; }
 
     // [string.view.modifiers], modifiers:
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     void remove_prefix(size_type __n) _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
-        __data += __n;
-        __size -= __n;
+        __data_ += __n;
+        __size_ -= __n;
     }
 
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     void remove_suffix(size_type __n) _NOEXCEPT
     {
         _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
-        __size -= __n;
+        __size_ -= __n;
     }
 
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     void swap(basic_string_view& __other) _NOEXCEPT
     {
-        const value_type *__p = __data;
-        __data = __other.__data;
-        __other.__data = __p;
-
-        size_type __sz = __size;
-        __size = __other.__size;
-        __other.__size = __sz;
+        const value_type *__p = __data_;
+        __data_ = __other.__data_;
+        __other.__data_ = __p;
+
+        size_type __sz = __size_;
+        __size_ = __other.__size_;
+        __other.__size_ = __sz;
     }
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
     {
         if (__pos > size())
             __throw_out_of_range("string_view::copy");
         size_type __rlen = _VSTD::min(__n, size() - __pos);
#if _LIBCPP_STD_VER > 20
     { return find(__c) != npos; }
 
     constexpr _LIBCPP_INLINE_VISIBILITY
     bool contains(const value_type* __s) const
     { return find(__s) != npos; }
 #endif
 
 private:
-    const   value_type* __data;
-    size_type           __size;
+    const   value_type* __data_;
+    size_type           __size_;
 };
 
 #if _LIBCPP_STD_VER > 17
 template <class _CharT, class _Traits>
 inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
 
 template <class _CharT, class _Traits>
 inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;

libcxx/include/unordered_map

 {
     typedef _Key                                     key_type;
     typedef _Tp                                      mapped_type;
     typedef pair<const key_type, mapped_type>        value_type;
     typedef pair<key_type&, mapped_type&>            __nc_ref_pair_type;
     typedef pair<key_type&&, mapped_type&&>          __nc_rref_pair_type;
 
 private:
-    value_type __cc;
+    value_type __cc_;
 
 public:
     _LIBCPP_INLINE_VISIBILITY
     value_type& __get_value()
     {
 #if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
+        return *_VSTD::launder(_VSTD::addressof(__cc_));
 #else
         return __cc;
 #endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
     const value_type& __get_value() const
     {
 #if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
+        return *_VSTD::launder(_VSTD::addressof(__cc_));
 #else
         return __cc;
 #endif
     }
 
     _LIBCPP_INLINE_VISIBILITY
     __nc_ref_pair_type __ref()
     {

libcxx/include/variant

return __union::__get_alt(_VSTD::forward<_Vp>(__v).__data,
                               in_place_index<_Ip>);
   }
 };
 
 struct __variant {
   template <size_t _Ip, class _Vp>
   inline _LIBCPP_INLINE_VISIBILITY
   static constexpr auto&& __get_alt(_Vp&& __v) {
-    return __base::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v).__impl);
+    return __base::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v).__impl_);
   }
 };
 
 } // namespace __access
 
 namespace __visitation {
 
 struct __base {

 
 struct __variant {
   template <class _Visitor, class... _Vs>
   inline _LIBCPP_INLINE_VISIBILITY
   static constexpr decltype(auto)
   __visit_alt_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) {
     return __base::__visit_alt_at(__index,
                                   _VSTD::forward<_Visitor>(__visitor),
-                                  _VSTD::forward<_Vs>(__vs).__impl...);
+                                  _VSTD::forward<_Vs>(__vs).__impl_...);
   }
 
   template <class _Visitor, class... _Vs>
   inline _LIBCPP_INLINE_VISIBILITY
   static constexpr decltype(auto) __visit_alt(_Visitor&& __visitor,
                                               _Vs&&... __vs) {
     return __base::__visit_alt(
         _VSTD::forward<_Visitor>(__visitor),
-        _VSTD::__as_variant(_VSTD::forward<_Vs>(__vs)).__impl...);
+        _VSTD::__as_variant(_VSTD::forward<_Vs>(__vs)).__impl_...);
   }
 
   template <class _Visitor, class... _Vs>
   inline _LIBCPP_INLINE_VISIBILITY
   static constexpr decltype(auto)
   __visit_value_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) {
     return __visit_alt_at(
         __index,

 
 public:
   template <bool _Dummy = true,
             enable_if_t<__dependent_type<is_default_constructible<__first_type>,
                                          _Dummy>::value,
                         int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   constexpr variant() noexcept(is_nothrow_default_constructible_v<__first_type>)
-      : __impl(in_place_index<0>) {}
+      : __impl_(in_place_index<0>) {}
 
   variant(const variant&) = default;
   variant(variant&&) = default;
 
   template <
       class _Arg,
       enable_if_t<!is_same_v<__uncvref_t<_Arg>, variant>, int> = 0,
       enable_if_t<!__is_inplace_type<__uncvref_t<_Arg>>::value, int> = 0,
       enable_if_t<!__is_inplace_index<__uncvref_t<_Arg>>::value, int> = 0,
       class _Tp = __variant_detail::__best_match_t<_Arg, _Types...>,
       size_t _Ip =
           __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
       enable_if_t<is_constructible_v<_Tp, _Arg>, int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   constexpr variant(_Arg&& __arg) noexcept(
       is_nothrow_constructible_v<_Tp, _Arg>)
-      : __impl(in_place_index<_Ip>, _VSTD::forward<_Arg>(__arg)) {}
+      : __impl_(in_place_index<_Ip>, _VSTD::forward<_Arg>(__arg)) {}
 
   template <size_t _Ip, class... _Args,
             class = enable_if_t<(_Ip < sizeof...(_Types)), int>,
             class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
             enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   explicit constexpr variant(
       in_place_index_t<_Ip>,
       _Args&&... __args) noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
-      : __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
+      : __impl_(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
 
   template <
       size_t _Ip,
       class _Up,
       class... _Args,
       enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
       class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
       enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
                   int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   explicit constexpr variant(
       in_place_index_t<_Ip>,
       initializer_list<_Up> __il,
       _Args&&... __args) noexcept(
       is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>)
-      : __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
+      : __impl_(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
 
   template <
       class _Tp,
       class... _Args,
       size_t _Ip =
           __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
       enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   explicit constexpr variant(in_place_type_t<_Tp>, _Args&&... __args) noexcept(
       is_nothrow_constructible_v<_Tp, _Args...>)
-      : __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
+      : __impl_(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
 
   template <
       class _Tp,
       class _Up,
       class... _Args,
       size_t _Ip =
           __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
       enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
                   int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   explicit constexpr variant(
       in_place_type_t<_Tp>,
       initializer_list<_Up> __il,
       _Args&&... __args) noexcept(
       is_nothrow_constructible_v<_Tp, initializer_list< _Up>&, _Args...>)
-      : __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
+      : __impl_(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
 
   ~variant() = default;
 
   variant& operator=(const variant&) = default;
   variant& operator=(variant&&) = default;
 
   template <
       class _Arg,
       enable_if_t<!is_same_v<__uncvref_t<_Arg>, variant>, int> = 0,
       class _Tp = __variant_detail::__best_match_t<_Arg, _Types...>,
       size_t _Ip =
           __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
       enable_if_t<is_assignable_v<_Tp&, _Arg> && is_constructible_v<_Tp, _Arg>,
                   int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   variant& operator=(_Arg&& __arg) noexcept(
       is_nothrow_assignable_v<_Tp&, _Arg> &&
       is_nothrow_constructible_v<_Tp, _Arg>) {
-    __impl.template __assign<_Ip>(_VSTD::forward<_Arg>(__arg));
+    __impl_.template __assign<_Ip>(_VSTD::forward<_Arg>(__arg));
     return *this;
   }
 
   template <
       size_t _Ip,
       class... _Args,
       enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
       class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
       enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   _Tp& emplace(_Args&&... __args) {
-    return __impl.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...);
+    return __impl_.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...);
   }
 
   template <
       size_t _Ip,
       class _Up,
       class... _Args,
       enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
       class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
       enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
                   int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) {
-    return __impl.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...);
+    return __impl_.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...);
   }
 
   template <
       class _Tp,
       class... _Args,
       size_t _Ip =
           __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
       enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   _Tp& emplace(_Args&&... __args) {
-    return __impl.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...);
+    return __impl_.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...);
   }
 
   template <
       class _Tp,
       class _Up,
       class... _Args,
       size_t _Ip =
           __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
       enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
                   int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) {
-    return __impl.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...);
+    return __impl_.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...);
   }
 
   inline _LIBCPP_INLINE_VISIBILITY
   constexpr bool valueless_by_exception() const noexcept {
-    return __impl.valueless_by_exception();
+    return __impl_.valueless_by_exception();
   }
 
   inline _LIBCPP_INLINE_VISIBILITY
-  constexpr size_t index() const noexcept { return __impl.index(); }
+  constexpr size_t index() const noexcept { return __impl_.index(); }
 
   template <
       bool _Dummy = true,
       enable_if_t<
           __all<(
               __dependent_type<is_move_constructible<_Types>, _Dummy>::value &&
               __dependent_type<is_swappable<_Types>, _Dummy>::value)...>::value,
           int> = 0>
   inline _LIBCPP_INLINE_VISIBILITY
   void swap(variant& __that) noexcept(
       __all<(is_nothrow_move_constructible_v<_Types> &&
              is_nothrow_swappable_v<_Types>)...>::value) {
-    __impl.__swap(__that.__impl);
+    __impl_.__swap(__that.__impl_);
   }
 
 private:
-  __variant_detail::__impl<_Types...> __impl;
+  __variant_detail::__impl<_Types...> __impl_;
 
   friend struct __variant_detail::__access::__variant;
   friend struct __variant_detail::__visitation::__variant;
 };
 
 template <size_t _Ip, class... _Types>
 inline _LIBCPP_INLINE_VISIBILITY
 constexpr bool __holds_alternative(const variant<_Types...>& __v) noexcept {

libcxx/src/locale.cpp

 {
     __id_ = __libcpp_atomic_add(&__next_id, 1);
 }
 
 // template <> class collate_byname<char>
 
 collate_byname<char>::collate_byname(const char* n, size_t refs)
     : collate<char>(refs),
-      __l(newlocale(LC_ALL_MASK, n, 0))
+      __l_(newlocale(LC_ALL_MASK, n, 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("collate_byname<char>::collate_byname"
                             " failed to construct for " + string(n));
 }
 
 collate_byname<char>::collate_byname(const string& name, size_t refs)
     : collate<char>(refs),
-      __l(newlocale(LC_ALL_MASK, name.c_str(), 0))
+      __l_(newlocale(LC_ALL_MASK, name.c_str(), 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("collate_byname<char>::collate_byname"
                             " failed to construct for " + name);
 }
 
 collate_byname<char>::~collate_byname()
 {
-    freelocale(__l);
+    freelocale(__l_);
 }
 
 int
 collate_byname<char>::do_compare(const char_type* __lo1, const char_type* __hi1,
                                  const char_type* __lo2, const char_type* __hi2) const
 {
     string_type lhs(__lo1, __hi1);
     string_type rhs(__lo2, __hi2);
-    int r = strcoll_l(lhs.c_str(), rhs.c_str(), __l);
+    int r = strcoll_l(lhs.c_str(), rhs.c_str(), __l_);
     if (r < 0)
         return -1;
     if (r > 0)
         return 1;
     return r;
 }
 
 collate_byname<char>::string_type
 collate_byname<char>::do_transform(const char_type* lo, const char_type* hi) const
 {
     const string_type in(lo, hi);
-    string_type out(strxfrm_l(0, in.c_str(), 0, __l), char());
-    strxfrm_l(const_cast<char*>(out.c_str()), in.c_str(), out.size()+1, __l);
+    string_type out(strxfrm_l(0, in.c_str(), 0, __l_), char());
+    strxfrm_l(const_cast<char*>(out.c_str()), in.c_str(), out.size()+1, __l_);
     return out;
 }
 
 // template <> class collate_byname<wchar_t>
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 collate_byname<wchar_t>::collate_byname(const char* n, size_t refs)
     : collate<wchar_t>(refs),
-      __l(newlocale(LC_ALL_MASK, n, 0))
+      __l_(newlocale(LC_ALL_MASK, n, 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("collate_byname<wchar_t>::collate_byname(size_t refs)"
                             " failed to construct for " + string(n));
 }
 
 collate_byname<wchar_t>::collate_byname(const string& name, size_t refs)
     : collate<wchar_t>(refs),
-      __l(newlocale(LC_ALL_MASK, name.c_str(), 0))
+      __l_(newlocale(LC_ALL_MASK, name.c_str(), 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("collate_byname<wchar_t>::collate_byname(size_t refs)"
                             " failed to construct for " + name);
 }
 
 collate_byname<wchar_t>::~collate_byname()
 {
-    freelocale(__l);
+    freelocale(__l_);
 }
 
 int
 collate_byname<wchar_t>::do_compare(const char_type* __lo1, const char_type* __hi1,
                                  const char_type* __lo2, const char_type* __hi2) const
 {
     string_type lhs(__lo1, __hi1);
     string_type rhs(__lo2, __hi2);
-    int r = wcscoll_l(lhs.c_str(), rhs.c_str(), __l);
+    int r = wcscoll_l(lhs.c_str(), rhs.c_str(), __l_);
     if (r < 0)
         return -1;
     if (r > 0)
         return 1;
     return r;
 }
 
 collate_byname<wchar_t>::string_type
 collate_byname<wchar_t>::do_transform(const char_type* lo, const char_type* hi) const
 {
     const string_type in(lo, hi);
-    string_type out(wcsxfrm_l(0, in.c_str(), 0, __l), wchar_t());
-    wcsxfrm_l(const_cast<wchar_t*>(out.c_str()), in.c_str(), out.size()+1, __l);
+    string_type out(wcsxfrm_l(0, in.c_str(), 0, __l_), wchar_t());
+    wcsxfrm_l(const_cast<wchar_t*>(out.c_str()), in.c_str(), out.size()+1, __l_);
     return out;
 }
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 const ctype_base::mask ctype_base::space;
 const ctype_base::mask ctype_base::print;
 const ctype_base::mask ctype_base::cntrl;
 const ctype_base::mask ctype_base::upper;

 # endif
 }
 #endif // __GLIBC__ || __NETBSD__ || __EMSCRIPTEN__ || __MVS__
 
 // template <> class ctype_byname<char>
 
 ctype_byname<char>::ctype_byname(const char* name, size_t refs)
     : ctype<char>(0, false, refs),
-      __l(newlocale(LC_ALL_MASK, name, 0))
+      __l_(newlocale(LC_ALL_MASK, name, 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("ctype_byname<char>::ctype_byname"
                             " failed to construct for " + string(name));
 }
 
 ctype_byname<char>::ctype_byname(const string& name, size_t refs)
     : ctype<char>(0, false, refs),
-      __l(newlocale(LC_ALL_MASK, name.c_str(), 0))
+      __l_(newlocale(LC_ALL_MASK, name.c_str(), 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("ctype_byname<char>::ctype_byname"
                             " failed to construct for " + name);
 }
 
 ctype_byname<char>::~ctype_byname()
 {
-    freelocale(__l);
+    freelocale(__l_);
 }
 
 char
 ctype_byname<char>::do_toupper(char_type c) const
 {
-    return static_cast<char>(toupper_l(static_cast<unsigned char>(c), __l));
+    return static_cast<char>(toupper_l(static_cast<unsigned char>(c), __l_));
 }
 
 const char*
 ctype_byname<char>::do_toupper(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
-        *low = static_cast<char>(toupper_l(static_cast<unsigned char>(*low), __l));
+        *low = static_cast<char>(toupper_l(static_cast<unsigned char>(*low), __l_));
     return low;
 }
 
 char
 ctype_byname<char>::do_tolower(char_type c) const
 {
-    return static_cast<char>(tolower_l(static_cast<unsigned char>(c), __l));
+    return static_cast<char>(tolower_l(static_cast<unsigned char>(c), __l_));
 }
 
 const char*
 ctype_byname<char>::do_tolower(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
-        *low = static_cast<char>(tolower_l(static_cast<unsigned char>(*low), __l));
+        *low = static_cast<char>(tolower_l(static_cast<unsigned char>(*low), __l_));
     return low;
 }
 
 // template <> class ctype_byname<wchar_t>
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 ctype_byname<wchar_t>::ctype_byname(const char* name, size_t refs)
     : ctype<wchar_t>(refs),
-      __l(newlocale(LC_ALL_MASK, name, 0))
+      __l_(newlocale(LC_ALL_MASK, name, 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("ctype_byname<wchar_t>::ctype_byname"
                             " failed to construct for " + string(name));
 }
 
 ctype_byname<wchar_t>::ctype_byname(const string& name, size_t refs)
     : ctype<wchar_t>(refs),
-      __l(newlocale(LC_ALL_MASK, name.c_str(), 0))
+      __l_(newlocale(LC_ALL_MASK, name.c_str(), 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("ctype_byname<wchar_t>::ctype_byname"
                             " failed to construct for " + name);
 }
 
 ctype_byname<wchar_t>::~ctype_byname()
 {
-    freelocale(__l);
+    freelocale(__l_);
 }
 
 bool
 ctype_byname<wchar_t>::do_is(mask m, char_type c) const
 {
 #ifdef _LIBCPP_WCTYPE_IS_MASK
-    return static_cast<bool>(iswctype_l(c, m, __l));
+    return static_cast<bool>(iswctype_l(c, m, __l_));
 #else
     bool result = false;
     wint_t ch = static_cast<wint_t>(c);
-    if ((m & space) == space) result |= (iswspace_l(ch, __l) != 0);
-    if ((m & print) == print) result |= (iswprint_l(ch, __l) != 0);
-    if ((m & cntrl) == cntrl) result |= (iswcntrl_l(ch, __l) != 0);
-    if ((m & upper) == upper) result |= (iswupper_l(ch, __l) != 0);
-    if ((m & lower) == lower) result |= (iswlower_l(ch, __l) != 0);
-    if ((m & alpha) == alpha) result |= (iswalpha_l(ch, __l) != 0);
-    if ((m & digit) == digit) result |= (iswdigit_l(ch, __l) != 0);
-    if ((m & punct) == punct) result |= (iswpunct_l(ch, __l) != 0);
-    if ((m & xdigit) == xdigit) result |= (iswxdigit_l(ch, __l) != 0);
-    if ((m & blank) == blank) result |= (iswblank_l(ch, __l) != 0);
+    if ((m & space) == space) result |= (iswspace_l(ch, __l_) != 0);
+    if ((m & print) == print) result |= (iswprint_l(ch, __l_) != 0);
+    if ((m & cntrl) == cntrl) result |= (iswcntrl_l(ch, __l_) != 0);
+    if ((m & upper) == upper) result |= (iswupper_l(ch, __l_) != 0);
+    if ((m & lower) == lower) result |= (iswlower_l(ch, __l_) != 0);
+    if ((m & alpha) == alpha) result |= (iswalpha_l(ch, __l_) != 0);
+    if ((m & digit) == digit) result |= (iswdigit_l(ch, __l_) != 0);
+    if ((m & punct) == punct) result |= (iswpunct_l(ch, __l_) != 0);
+    if ((m & xdigit) == xdigit) result |= (iswxdigit_l(ch, __l_) != 0);
+    if ((m & blank) == blank) result |= (iswblank_l(ch, __l_) != 0);
     return result;
 #endif
 }
 
 const wchar_t*
 ctype_byname<wchar_t>::do_is(const char_type* low, const char_type* high, mask* vec) const
 {
     for (; low != high; ++low, ++vec)
     {
         if (isascii(*low))
             *vec = static_cast<mask>(ctype<char>::classic_table()[*low]);
         else
         {
             *vec = 0;
             wint_t ch = static_cast<wint_t>(*low);
-            if (iswspace_l(ch, __l))
+            if (iswspace_l(ch, __l_))
                 *vec |= space;
 #ifndef _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
-            if (iswprint_l(ch, __l))
+            if (iswprint_l(ch, __l_))
                 *vec |= print;
 #endif
-            if (iswcntrl_l(ch, __l))
+            if (iswcntrl_l(ch, __l_))
                 *vec |= cntrl;
-            if (iswupper_l(ch, __l))
+            if (iswupper_l(ch, __l_))
                 *vec |= upper;
-            if (iswlower_l(ch, __l))
+            if (iswlower_l(ch, __l_))
                 *vec |= lower;
 #ifndef _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
-            if (iswalpha_l(ch, __l))
+            if (iswalpha_l(ch, __l_))
                 *vec |= alpha;
 #endif
-            if (iswdigit_l(ch, __l))
+            if (iswdigit_l(ch, __l_))
                 *vec |= digit;
-            if (iswpunct_l(ch, __l))
+            if (iswpunct_l(ch, __l_))
                 *vec |= punct;
 #ifndef _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
-            if (iswxdigit_l(ch, __l))
+            if (iswxdigit_l(ch, __l_))
                 *vec |= xdigit;
 #endif
 #if !defined(__sun__)
-            if (iswblank_l(ch, __l))
+            if (iswblank_l(ch, __l_))
                 *vec |= blank;
 #endif
         }
     }
     return low;
 }
 
 const wchar_t*
 ctype_byname<wchar_t>::do_scan_is(mask m, const char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
     {
 #ifdef _LIBCPP_WCTYPE_IS_MASK
         if (iswctype_l(*low, m, __l))
             break;
 #else
         wint_t ch = static_cast<wint_t>(*low);
-        if ((m & space) == space && iswspace_l(ch, __l)) break;
-        if ((m & print) == print && iswprint_l(ch, __l)) break;
-        if ((m & cntrl) == cntrl && iswcntrl_l(ch, __l)) break;
-        if ((m & upper) == upper && iswupper_l(ch, __l)) break;
-        if ((m & lower) == lower && iswlower_l(ch, __l)) break;
-        if ((m & alpha) == alpha && iswalpha_l(ch, __l)) break;
-        if ((m & digit) == digit && iswdigit_l(ch, __l)) break;
-        if ((m & punct) == punct && iswpunct_l(ch, __l)) break;
-        if ((m & xdigit) == xdigit && iswxdigit_l(ch, __l)) break;
-        if ((m & blank) == blank && iswblank_l(ch, __l)) break;
+        if ((m & space) == space && iswspace_l(ch, __l_)) break;
+        if ((m & print) == print && iswprint_l(ch, __l_)) break;
+        if ((m & cntrl) == cntrl && iswcntrl_l(ch, __l_)) break;
+        if ((m & upper) == upper && iswupper_l(ch, __l_)) break;
+        if ((m & lower) == lower && iswlower_l(ch, __l_)) break;
+        if ((m & alpha) == alpha && iswalpha_l(ch, __l_)) break;
+        if ((m & digit) == digit && iswdigit_l(ch, __l_)) break;
+        if ((m & punct) == punct && iswpunct_l(ch, __l_)) break;
+        if ((m & xdigit) == xdigit && iswxdigit_l(ch, __l_)) break;
+        if ((m & blank) == blank && iswblank_l(ch, __l_)) break;
 #endif
     }
     return low;
 }
 
 const wchar_t*
 ctype_byname<wchar_t>::do_scan_not(mask m, const char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
     {
 #ifdef _LIBCPP_WCTYPE_IS_MASK
-        if (!iswctype_l(*low, m, __l))
+        if (!iswctype_l(*low, m, __l_))
             break;
 #else
         wint_t ch = static_cast<wint_t>(*low);
-        if ((m & space) == space && iswspace_l(ch, __l)) continue;
-        if ((m & print) == print && iswprint_l(ch, __l)) continue;
-        if ((m & cntrl) == cntrl && iswcntrl_l(ch, __l)) continue;
-        if ((m & upper) == upper && iswupper_l(ch, __l)) continue;
-        if ((m & lower) == lower && iswlower_l(ch, __l)) continue;
-        if ((m & alpha) == alpha && iswalpha_l(ch, __l)) continue;
-        if ((m & digit) == digit && iswdigit_l(ch, __l)) continue;
-        if ((m & punct) == punct && iswpunct_l(ch, __l)) continue;
-        if ((m & xdigit) == xdigit && iswxdigit_l(ch, __l)) continue;
-        if ((m & blank) == blank && iswblank_l(ch, __l)) continue;
+        if ((m & space) == space && iswspace_l(ch, __l_)) continue;
+        if ((m & print) == print && iswprint_l(ch, __l_)) continue;
+        if ((m & cntrl) == cntrl && iswcntrl_l(ch, __l_)) continue;
+        if ((m & upper) == upper && iswupper_l(ch, __l_)) continue;
+        if ((m & lower) == lower && iswlower_l(ch, __l_)) continue;
+        if ((m & alpha) == alpha && iswalpha_l(ch, __l_)) continue;
+        if ((m & digit) == digit && iswdigit_l(ch, __l_)) continue;
+        if ((m & punct) == punct && iswpunct_l(ch, __l_)) continue;
+        if ((m & xdigit) == xdigit && iswxdigit_l(ch, __l_)) continue;
+        if ((m & blank) == blank && iswblank_l(ch, __l_)) continue;
         break;
 #endif
     }
     return low;
 }
 
 wchar_t
 ctype_byname<wchar_t>::do_toupper(char_type c) const
 {
-    return towupper_l(c, __l);
+    return towupper_l(c, __l_);
 }
 
 const wchar_t*
 ctype_byname<wchar_t>::do_toupper(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
-        *low = towupper_l(*low, __l);
+        *low = towupper_l(*low, __l_);
     return low;
 }
 
 wchar_t
 ctype_byname<wchar_t>::do_tolower(char_type c) const
 {
-    return towlower_l(c, __l);
+    return towlower_l(c, __l_);
 }
 
 const wchar_t*
 ctype_byname<wchar_t>::do_tolower(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
-        *low = towlower_l(*low, __l);
+        *low = towlower_l(*low, __l_);
     return low;
 }
 
 wchar_t
 ctype_byname<wchar_t>::do_widen(char c) const
 {
-    return __libcpp_btowc_l(c, __l);
+    return __libcpp_btowc_l(c, __l_);
 }
 
 const char*
 ctype_byname<wchar_t>::do_widen(const char* low, const char* high, char_type* dest) const
 {
     for (; low != high; ++low, ++dest)
-        *dest = __libcpp_btowc_l(*low, __l);
+        *dest = __libcpp_btowc_l(*low, __l_);
     return low;
 }
 
 char
 ctype_byname<wchar_t>::do_narrow(char_type c, char dfault) const
 {
-    int r = __libcpp_wctob_l(c, __l);
+    int r = __libcpp_wctob_l(c, __l_);
     return (r != EOF) ? static_cast<char>(r) : dfault;
 }
 
 const wchar_t*
 ctype_byname<wchar_t>::do_narrow(const char_type* low, const char_type* high, char dfault, char* dest) const
 {
     for (; low != high; ++low, ++dest)
     {
-        int r = __libcpp_wctob_l(*low, __l);
+        int r = __libcpp_wctob_l(*low, __l_);
         *dest = (r != EOF) ? static_cast<char>(r) : dfault;
     }
     return low;
 }
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 // template <> class codecvt<char, char, mbstate_t>
 

 
 // template <> class codecvt<wchar_t, char, mbstate_t>
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 locale::id codecvt<wchar_t, char, mbstate_t>::id;
 
 codecvt<wchar_t, char, mbstate_t>::codecvt(size_t refs)
     : locale::facet(refs),
-      __l(_LIBCPP_GET_C_LOCALE)
+      __l_(_LIBCPP_GET_C_LOCALE)
 {
 }
 
 codecvt<wchar_t, char, mbstate_t>::codecvt(const char* nm, size_t refs)
     : locale::facet(refs),
-      __l(newlocale(LC_ALL_MASK, nm, 0))
+      __l_(newlocale(LC_ALL_MASK, nm, 0))
 {
-    if (__l == 0)
+    if (__l_ == 0)
         __throw_runtime_error("codecvt_byname<wchar_t, char, mbstate_t>::codecvt_byname"
                             " failed to construct for " + string(nm));
 }
 
 codecvt<wchar_t, char, mbstate_t>::~codecvt()
 {
-    if (__l != _LIBCPP_GET_C_LOCALE)
-        freelocale(__l);
+    if (__l_ != _LIBCPP_GET_C_LOCALE)
+        freelocale(__l_);
 }
 
 codecvt<wchar_t, char, mbstate_t>::result
 codecvt<wchar_t, char, mbstate_t>::do_out(state_type& st,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     // look for first internal null in frm
     const intern_type* fend = frm;
     for (; fend != frm_end; ++fend)
         if (*fend == 0)
             break;
     // loop over all null-terminated sequences in frm
     to_nxt = to;
     for (frm_nxt = frm; frm != frm_end && to != to_end; frm = frm_nxt, to = to_nxt)
     {
         // save state in case it is needed to recover to_nxt on error
         mbstate_t save_state = st;
         size_t n = __libcpp_wcsnrtombs_l(to, &frm_nxt, static_cast<size_t>(fend-frm),
-                                     static_cast<size_t>(to_end-to), &st, __l);
+                                     static_cast<size_t>(to_end-to), &st, __l_);
         if (n == size_t(-1))
         {
             // need to recover to_nxt
             for (to_nxt = to; frm != frm_nxt; ++frm)
             {
-                n = __libcpp_wcrtomb_l(to_nxt, *frm, &save_state, __l);
+                n = __libcpp_wcrtomb_l(to_nxt, *frm, &save_state, __l_);
                 if (n == size_t(-1))
                     break;
                 to_nxt += n;
             }
             frm_nxt = frm;
             return error;
         }
         if (n == 0)
             return partial;
         to_nxt += n;
         if (to_nxt == to_end)
             break;
         if (fend != frm_end)  // set up next null terminated sequence
         {
             // Try to write the terminating null
             extern_type tmp[MB_LEN_MAX];
-            n = __libcpp_wcrtomb_l(tmp, intern_type(), &st, __l);
+            n = __libcpp_wcrtomb_l(tmp, intern_type(), &st, __l_);
             if (n == size_t(-1))  // on error
                 return error;
             if (n > static_cast<size_t>(to_end-to_nxt))  // is there room?
                 return partial;
             for (extern_type* p = tmp; n; --n)  // write it
                 *to_nxt++ = *p++;
             ++frm_nxt;
             // look for next null in frm
for (; fend != frm_end; ++fend)
             break;
     // loop over all null-terminated sequences in frm
     to_nxt = to;
     for (frm_nxt = frm; frm != frm_end && to != to_end; frm = frm_nxt, to = to_nxt)
     {
         // save state in case it is needed to recover to_nxt on error
         mbstate_t save_state = st;
         size_t n = __libcpp_mbsnrtowcs_l(to, &frm_nxt, static_cast<size_t>(fend-frm),
-                                     static_cast<size_t>(to_end-to), &st, __l);
+                                     static_cast<size_t>(to_end-to), &st, __l_);
         if (n == size_t(-1))
         {
             // need to recover to_nxt
             for (to_nxt = to; frm != frm_nxt; ++to_nxt)
             {
                 n = __libcpp_mbrtowc_l(to_nxt, frm, static_cast<size_t>(fend-frm),
-                                   &save_state, __l);
+                                   &save_state, __l_);
                 switch (n)
                 {
                 case 0:
                     ++frm;
                     break;
                 case size_t(-1):
                     frm_nxt = frm;
                     return error;
for (frm_nxt = frm; frm != frm_end && to != to_end; frm = frm_nxt, to = to_nxt)
         if (n == size_t(-1))
             return error;
         to_nxt += n;
         if (to_nxt == to_end)
             break;
         if (fend != frm_end)  // set up next null terminated sequence
         {
             // Try to write the terminating null
-            n = __libcpp_mbrtowc_l(to_nxt, frm_nxt, 1, &st, __l);
+            n = __libcpp_mbrtowc_l(to_nxt, frm_nxt, 1, &st, __l_);
             if (n != 0)  // on error
                 return error;
             ++to_nxt;
             ++frm_nxt;
             // look for next null in frm
             for (fend = frm_nxt; fend != frm_end; ++fend)
                 if (*fend == 0)
                     break;
         }
     }
     return frm_nxt == frm_end ? ok : partial;
 }
 
 codecvt<wchar_t, char, mbstate_t>::result
 codecvt<wchar_t, char, mbstate_t>::do_unshift(state_type& st,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     to_nxt = to;
     extern_type tmp[MB_LEN_MAX];
-    size_t n = __libcpp_wcrtomb_l(tmp, intern_type(), &st, __l);
+    size_t n = __libcpp_wcrtomb_l(tmp, intern_type(), &st, __l_);
     if (n == size_t(-1) || n == 0)  // on error
         return error;
     --n;
     if (n > static_cast<size_t>(to_end-to_nxt))  // is there room?
         return partial;
     for (extern_type* p = tmp; n; --n)  // write it
         *to_nxt++ = *p++;
     return ok;
 }
 
 int
 codecvt<wchar_t, char, mbstate_t>::do_encoding() const noexcept
 {
-    if (__libcpp_mbtowc_l(nullptr, nullptr, MB_LEN_MAX, __l) != 0)
+    if (__libcpp_mbtowc_l(nullptr, nullptr, MB_LEN_MAX, __l_) != 0)
         return -1;
 
     // stateless encoding
-    if (__l == 0 || __libcpp_mb_cur_max_l(__l) == 1)  // there are no known constant length encodings
+    if (__l_ == 0 || __libcpp_mb_cur_max_l(__l_) == 1)  // there are no known constant length encodings
         return 1;                // which take more than 1 char to form a wchar_t
     return 0;
 }
 
 bool
 codecvt<wchar_t, char, mbstate_t>::do_always_noconv() const noexcept
 {
     return false;
 }
 
 int
 codecvt<wchar_t, char, mbstate_t>::do_length(state_type& st,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     int nbytes = 0;
     for (size_t nwchar_t = 0; nwchar_t < mx && frm != frm_end; ++nwchar_t)
     {
-        size_t n = __libcpp_mbrlen_l(frm, static_cast<size_t>(frm_end-frm), &st, __l);
+        size_t n = __libcpp_mbrlen_l(frm, static_cast<size_t>(frm_end-frm), &st, __l_);
         switch (n)
         {
         case 0:
             ++nbytes;
             ++frm;
             break;
         case size_t(-1):
         case size_t(-2):
             return nbytes;
         default:
             nbytes += n;
             frm += n;
             break;
         }
     }
     return nbytes;
 }
 
 int
 codecvt<wchar_t, char, mbstate_t>::do_max_length() const noexcept
 {
-    return __l == 0 ? 1 : static_cast<int>(__libcpp_mb_cur_max_l(__l));
+    return __l_ == 0 ? 1 : static_cast<int>(__libcpp_mb_cur_max_l(__l_));
 }
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 //                                     Valid UTF ranges
 //     UTF-32               UTF-16                          UTF-8               # of code points
 //                     first      second       first   second    third   fourth
 // 000000 - 00007F  0000 - 007F               00 - 7F                                 127
 // 000080 - 0007FF  0080 - 07FF               C2 - DF, 80 - BF                       1920
#else
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
 #endif
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
 #if defined(_LIBCPP_SHORT_WCHAR)
     result r = ucs2_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
 #else
     result r = ucs4_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
 #endif
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8<wchar_t>::result
 __codecvt_utf8<wchar_t>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
 #if defined(_LIBCPP_SHORT_WCHAR)
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf8_to_ucs2(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
 #else
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf8_to_ucs4(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
 #endif
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8<wchar_t>::result
 __codecvt_utf8<wchar_t>::do_unshift(state_type&,

 
 int
 __codecvt_utf8<wchar_t>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
 #if defined(_LIBCPP_SHORT_WCHAR)
-    return utf8_to_ucs2_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_ucs2_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 #else
-    return utf8_to_ucs4_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_ucs4_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 #endif
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf8<wchar_t>::do_max_length() const noexcept
 {
 #if defined(_LIBCPP_SHORT_WCHAR)
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 6;
     return 3;
 #else
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 7;
     return 4;
 #endif
 }
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 // __codecvt_utf8<char16_t>
 
 __codecvt_utf8<char16_t>::result
 __codecvt_utf8<char16_t>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint16_t* _frm = reinterpret_cast<const uint16_t*>(frm);
     const uint16_t* _frm_end = reinterpret_cast<const uint16_t*>(frm_end);
     const uint16_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = ucs2_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8<char16_t>::result
 __codecvt_utf8<char16_t>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf8_to_ucs2(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8<char16_t>::result
 __codecvt_utf8<char16_t>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf8<char16_t>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf8_to_ucs2_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_ucs2_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf8<char16_t>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 6;
     return 3;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf8<char32_t>
 
 __codecvt_utf8<char32_t>::result
 __codecvt_utf8<char32_t>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint32_t* _frm = reinterpret_cast<const uint32_t*>(frm);
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = ucs4_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8<char32_t>::result
 __codecvt_utf8<char32_t>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf8_to_ucs4(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                            _Maxcode_, _Mode_);
+                            __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8<char32_t>::result
 __codecvt_utf8<char32_t>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf8<char32_t>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf8_to_ucs4_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_ucs4_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf8<char32_t>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 7;
     return 4;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf16<wchar_t, false>
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
#else
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
 #endif
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
 #if defined(_LIBCPP_SHORT_WCHAR)
     result r = ucs2_to_utf16be(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #else
     result r = ucs4_to_utf16be(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #endif
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<wchar_t, false>::result
 __codecvt_utf16<wchar_t, false>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
 #if defined(_LIBCPP_SHORT_WCHAR)
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf16be_to_ucs2(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #else
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf16be_to_ucs4(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #endif
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<wchar_t, false>::result
 __codecvt_utf16<wchar_t, false>::do_unshift(state_type&,

 
 int
 __codecvt_utf16<wchar_t, false>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
 #if defined(_LIBCPP_SHORT_WCHAR)
-    return utf16be_to_ucs2_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16be_to_ucs2_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 #else
-    return utf16be_to_ucs4_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16be_to_ucs4_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 #endif
 }
 
 int
 __codecvt_utf16<wchar_t, false>::do_max_length() const noexcept
 {
 #if defined(_LIBCPP_SHORT_WCHAR)
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 4;
     return 2;
 #else
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 6;
     return 4;
 #endif
 }
 
 // __codecvt_utf16<wchar_t, true>
 
 __codecvt_utf16<wchar_t, true>::result
#else
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
 #endif
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
 #if defined(_LIBCPP_SHORT_WCHAR)
     result r = ucs2_to_utf16le(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #else
     result r = ucs4_to_utf16le(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #endif
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<wchar_t, true>::result
 __codecvt_utf16<wchar_t, true>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
 #if defined(_LIBCPP_SHORT_WCHAR)
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf16le_to_ucs2(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #else
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf16le_to_ucs4(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
 #endif
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<wchar_t, true>::result
 __codecvt_utf16<wchar_t, true>::do_unshift(state_type&,

 
 int
 __codecvt_utf16<wchar_t, true>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
 #if defined(_LIBCPP_SHORT_WCHAR)
-    return utf16le_to_ucs2_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16le_to_ucs2_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 #else
-    return utf16le_to_ucs4_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16le_to_ucs4_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 #endif
 }
 
 int
 __codecvt_utf16<wchar_t, true>::do_max_length() const noexcept
 {
 #if defined(_LIBCPP_SHORT_WCHAR)
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 4;
     return 2;
 #else
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 6;
     return 4;
 #endif
 }
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 // __codecvt_utf16<char16_t, false>
 
 __codecvt_utf16<char16_t, false>::result
 __codecvt_utf16<char16_t, false>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint16_t* _frm = reinterpret_cast<const uint16_t*>(frm);
     const uint16_t* _frm_end = reinterpret_cast<const uint16_t*>(frm_end);
     const uint16_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = ucs2_to_utf16be(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char16_t, false>::result
 __codecvt_utf16<char16_t, false>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf16be_to_ucs2(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char16_t, false>::result
 __codecvt_utf16<char16_t, false>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf16<char16_t, false>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf16be_to_ucs2_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16be_to_ucs2_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf16<char16_t, false>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 4;
     return 2;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf16<char16_t, true>
 
 __codecvt_utf16<char16_t, true>::result
 __codecvt_utf16<char16_t, true>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint16_t* _frm = reinterpret_cast<const uint16_t*>(frm);
     const uint16_t* _frm_end = reinterpret_cast<const uint16_t*>(frm_end);
     const uint16_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = ucs2_to_utf16le(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char16_t, true>::result
 __codecvt_utf16<char16_t, true>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf16le_to_ucs2(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char16_t, true>::result
 __codecvt_utf16<char16_t, true>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf16<char16_t, true>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf16le_to_ucs2_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16le_to_ucs2_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf16<char16_t, true>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 4;
     return 2;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf16<char32_t, false>
 
 __codecvt_utf16<char32_t, false>::result
 __codecvt_utf16<char32_t, false>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint32_t* _frm = reinterpret_cast<const uint32_t*>(frm);
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = ucs4_to_utf16be(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char32_t, false>::result
 __codecvt_utf16<char32_t, false>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf16be_to_ucs4(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char32_t, false>::result
 __codecvt_utf16<char32_t, false>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf16<char32_t, false>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf16be_to_ucs4_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16be_to_ucs4_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf16<char32_t, false>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 6;
     return 4;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf16<char32_t, true>
 
 __codecvt_utf16<char32_t, true>::result
 __codecvt_utf16<char32_t, true>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint32_t* _frm = reinterpret_cast<const uint32_t*>(frm);
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = ucs4_to_utf16le(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char32_t, true>::result
 __codecvt_utf16<char32_t, true>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf16le_to_ucs4(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                               _Maxcode_, _Mode_);
+                               __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf16<char32_t, true>::result
 __codecvt_utf16<char32_t, true>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf16<char32_t, true>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf16le_to_ucs4_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf16le_to_ucs4_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf16<char32_t, true>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 6;
     return 4;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf8_utf16<wchar_t>
 
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
#else
     const uint32_t* _frm = reinterpret_cast<const uint32_t*>(frm);
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
 #endif
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = utf16_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                             _Maxcode_, _Mode_);
+                             __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8_utf16<wchar_t>::result
 __codecvt_utf8_utf16<wchar_t>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
 #if defined(_LIBCPP_SHORT_WCHAR)
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
 #else
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
 #endif
     result r = utf8_to_utf16(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                             _Maxcode_, _Mode_);
+                             __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8_utf16<wchar_t>::result
 __codecvt_utf8_utf16<wchar_t>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf8_utf16<wchar_t>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf8_to_utf16_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_utf16_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 int
 __codecvt_utf8_utf16<wchar_t>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 7;
     return 4;
 }
 #endif // _LIBCPP_HAS_NO_WIDE_CHARACTERS
 
 // __codecvt_utf8_utf16<char16_t>
 
 __codecvt_utf8_utf16<char16_t>::result
 __codecvt_utf8_utf16<char16_t>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint16_t* _frm = reinterpret_cast<const uint16_t*>(frm);
     const uint16_t* _frm_end = reinterpret_cast<const uint16_t*>(frm_end);
     const uint16_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = utf16_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                             _Maxcode_, _Mode_);
+                             __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8_utf16<char16_t>::result
 __codecvt_utf8_utf16<char16_t>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint16_t* _to = reinterpret_cast<uint16_t*>(to);
     uint16_t* _to_end = reinterpret_cast<uint16_t*>(to_end);
     uint16_t* _to_nxt = _to;
     result r = utf8_to_utf16(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                             _Maxcode_, _Mode_);
+                             __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8_utf16<char16_t>::result
 __codecvt_utf8_utf16<char16_t>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf8_utf16<char16_t>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf8_to_utf16_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_utf16_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf8_utf16<char16_t>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 7;
     return 4;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __codecvt_utf8_utf16<char32_t>
 
 __codecvt_utf8_utf16<char32_t>::result
 __codecvt_utf8_utf16<char32_t>::do_out(state_type&,
     const intern_type* frm, const intern_type* frm_end, const intern_type*& frm_nxt,
     extern_type* to, extern_type* to_end, extern_type*& to_nxt) const
 {
     const uint32_t* _frm = reinterpret_cast<const uint32_t*>(frm);
     const uint32_t* _frm_end = reinterpret_cast<const uint32_t*>(frm_end);
     const uint32_t* _frm_nxt = _frm;
     uint8_t* _to = reinterpret_cast<uint8_t*>(to);
     uint8_t* _to_end = reinterpret_cast<uint8_t*>(to_end);
     uint8_t* _to_nxt = _to;
     result r = utf16_to_utf8(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                             _Maxcode_, _Mode_);
+                             __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8_utf16<char32_t>::result
 __codecvt_utf8_utf16<char32_t>::do_in(state_type&,
     const extern_type* frm, const extern_type* frm_end, const extern_type*& frm_nxt,
     intern_type* to, intern_type* to_end, intern_type*& to_nxt) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
     const uint8_t* _frm_nxt = _frm;
     uint32_t* _to = reinterpret_cast<uint32_t*>(to);
     uint32_t* _to_end = reinterpret_cast<uint32_t*>(to_end);
     uint32_t* _to_nxt = _to;
     result r = utf8_to_utf16(_frm, _frm_end, _frm_nxt, _to, _to_end, _to_nxt,
-                             _Maxcode_, _Mode_);
+                             __maxcode_, __mode_);
     frm_nxt = frm + (_frm_nxt - _frm);
     to_nxt = to + (_to_nxt - _to);
     return r;
 }
 
 __codecvt_utf8_utf16<char32_t>::result
 __codecvt_utf8_utf16<char32_t>::do_unshift(state_type&,
     extern_type* to, extern_type*, extern_type*& to_nxt) const

 }
 
 int
 __codecvt_utf8_utf16<char32_t>::do_length(state_type&,
     const extern_type* frm, const extern_type* frm_end, size_t mx) const
 {
     const uint8_t* _frm = reinterpret_cast<const uint8_t*>(frm);
     const uint8_t* _frm_end = reinterpret_cast<const uint8_t*>(frm_end);
-    return utf8_to_utf16_length(_frm, _frm_end, mx, _Maxcode_, _Mode_);
+    return utf8_to_utf16_length(_frm, _frm_end, mx, __maxcode_, __mode_);
 }
 
 _LIBCPP_SUPPRESS_DEPRECATED_PUSH
 int
 __codecvt_utf8_utf16<char32_t>::do_max_length() const noexcept
 {
-    if (_Mode_ & consume_header)
+    if (__mode_ & consume_header)
         return 7;
     return 4;
 }
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 // __narrow_to_utf8<16>
 
 __narrow_to_utf8<16>::~__narrow_to_utf8()

libcxx/src/memory.cpp

static constinit __libcpp_mutex_t mut_back[__sp_mut_count] =
     _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
     _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
     _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
     _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER,
     _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER, _LIBCPP_MUTEX_INITIALIZER
 };
 
 _LIBCPP_CONSTEXPR __sp_mut::__sp_mut(void* p) noexcept
-   : __lx(p)
+   : __lx_(p)
 {
 }
 
 void
 __sp_mut::lock() noexcept
 {
-    auto m = static_cast<__libcpp_mutex_t*>(__lx);
+    auto m = static_cast<__libcpp_mutex_t*>(__lx_);
     __libcpp_mutex_lock(m);
 }
 
 void
 __sp_mut::unlock() noexcept
 {
-    __libcpp_mutex_unlock(static_cast<__libcpp_mutex_t*>(__lx));
+    __libcpp_mutex_unlock(static_cast<__libcpp_mutex_t*>(__lx_));
 }
 
 __sp_mut&
 __get_sp_mut(const void* p)
 {
     static constinit __sp_mut muts[__sp_mut_count] = {
         &mut_back[ 0], &mut_back[ 1], &mut_back[ 2], &mut_back[ 3],
         &mut_back[ 4], &mut_back[ 5], &mut_back[ 6], &mut_back[ 7],

libcxx/src/shared_mutex.cpp

else
         if (num_readers == __n_readers_ - 1)
             __gate1_.notify_one();
     }
 }
 
 
 // Shared Timed Mutex
 // These routines are here for ABI stability
-shared_timed_mutex::shared_timed_mutex() : __base() {}
-void shared_timed_mutex::lock()     { return __base.lock(); }
-bool shared_timed_mutex::try_lock() { return __base.try_lock(); }
-void shared_timed_mutex::unlock()   { return __base.unlock(); }
-void shared_timed_mutex::lock_shared() { return __base.lock_shared(); }
-bool shared_timed_mutex::try_lock_shared() { return __base.try_lock_shared(); }
-void shared_timed_mutex::unlock_shared() { return __base.unlock_shared(); }
+shared_timed_mutex::shared_timed_mutex() : __base_() {}
+void shared_timed_mutex::lock()     { return __base_.lock(); }
+bool shared_timed_mutex::try_lock() { return __base_.try_lock(); }
+void shared_timed_mutex::unlock()   { return __base_.unlock(); }
+void shared_timed_mutex::lock_shared() { return __base_.lock_shared(); }
+bool shared_timed_mutex::try_lock_shared() { return __base_.try_lock_shared(); }
+void shared_timed_mutex::unlock_shared() { return __base_.unlock_shared(); }
 
 _LIBCPP_END_NAMESPACE_STD
 
 #endif // !_LIBCPP_HAS_NO_THREADS