xref: /llvm-project/libcxx/include/__format/format_functions.h (revision 14b44179cb61dd551c911dea54de57b588621005)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef _LIBCPP___FORMAT_FORMAT_FUNCTIONS
11 #define _LIBCPP___FORMAT_FORMAT_FUNCTIONS
12 
13 #include <__algorithm/clamp.h>
14 #include <__concepts/convertible_to.h>
15 #include <__concepts/same_as.h>
16 #include <__config>
17 #include <__format/buffer.h>
18 #include <__format/format_arg.h>
19 #include <__format/format_arg_store.h>
20 #include <__format/format_args.h>
21 #include <__format/format_context.h>
22 #include <__format/format_error.h>
23 #include <__format/format_parse_context.h>
24 #include <__format/format_string.h>
25 #include <__format/format_to_n_result.h>
26 #include <__format/formatter.h>
27 #include <__format/formatter_bool.h>
28 #include <__format/formatter_char.h>
29 #include <__format/formatter_floating_point.h>
30 #include <__format/formatter_integer.h>
31 #include <__format/formatter_pointer.h>
32 #include <__format/formatter_string.h>
33 #include <__format/parser_std_format_spec.h>
34 #include <__iterator/concepts.h>
35 #include <__iterator/incrementable_traits.h>
36 #include <__iterator/iterator_traits.h> // iter_value_t
37 #include <__variant/monostate.h>
38 #include <array>
39 #include <string>
40 #include <string_view>
41 
42 #if _LIBCPP_HAS_LOCALIZATION
43 #  include <__locale>
44 #endif
45 
46 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
47 #  pragma GCC system_header
48 #endif
49 
50 _LIBCPP_PUSH_MACROS
51 #include <__undef_macros>
52 
53 _LIBCPP_BEGIN_NAMESPACE_STD
54 
55 #if _LIBCPP_STD_VER >= 20
56 
57 // TODO FMT Evaluate which templates should be external templates. This
58 // improves the efficiency of the header. However since the header is still
59 // under heavy development and not all classes are stable it makes no sense
60 // to do this optimization now.
61 
62 using format_args = basic_format_args<format_context>;
63 #  if _LIBCPP_HAS_WIDE_CHARACTERS
64 using wformat_args = basic_format_args<wformat_context>;
65 #  endif
66 
67 template <class _Context = format_context, class... _Args>
68 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __format_arg_store<_Context, _Args...> make_format_args(_Args&... __args) {
69   return std::__format_arg_store<_Context, _Args...>(__args...);
70 }
71 
72 #  if _LIBCPP_HAS_WIDE_CHARACTERS
73 template <class... _Args>
74 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI __format_arg_store<wformat_context, _Args...> make_wformat_args(_Args&... __args) {
75   return std::__format_arg_store<wformat_context, _Args...>(__args...);
76 }
77 #  endif
78 
79 namespace __format {
80 
81 /// Helper class parse and handle argument.
82 ///
83 /// When parsing a handle which is not enabled the code is ill-formed.
84 /// This helper uses the parser of the appropriate formatter for the stored type.
85 template <class _CharT>
86 class _LIBCPP_TEMPLATE_VIS __compile_time_handle {
87 public:
88   template <class _ParseContext>
89   _LIBCPP_HIDE_FROM_ABI constexpr void __parse(_ParseContext& __ctx) const {
90     __parse_(__ctx);
91   }
92 
93   template <class _Tp>
94   _LIBCPP_HIDE_FROM_ABI constexpr void __enable() {
95     __parse_ = [](basic_format_parse_context<_CharT>& __ctx) {
96       formatter<_Tp, _CharT> __f;
97       __ctx.advance_to(__f.parse(__ctx));
98     };
99   }
100 
101   // Before calling __parse the proper handler needs to be set with __enable.
102   // The default handler isn't a core constant expression.
103   _LIBCPP_HIDE_FROM_ABI constexpr __compile_time_handle()
104       : __parse_([](basic_format_parse_context<_CharT>&) { std::__throw_format_error("Not a handle"); }) {}
105 
106 private:
107   void (*__parse_)(basic_format_parse_context<_CharT>&);
108 };
109 
110 // Dummy format_context only providing the parts used during constant
111 // validation of the basic_format_string.
112 template <class _CharT>
113 struct _LIBCPP_TEMPLATE_VIS __compile_time_basic_format_context {
114 public:
115   using char_type = _CharT;
116 
117   _LIBCPP_HIDE_FROM_ABI constexpr explicit __compile_time_basic_format_context(
118       const __arg_t* __args, const __compile_time_handle<_CharT>* __handles, size_t __size)
119       : __args_(__args), __handles_(__handles), __size_(__size) {}
120 
121   // During the compile-time validation nothing needs to be written.
122   // Therefore all operations of this iterator are a NOP.
123   struct iterator {
124     _LIBCPP_HIDE_FROM_ABI constexpr iterator& operator=(_CharT) { return *this; }
125     _LIBCPP_HIDE_FROM_ABI constexpr iterator& operator*() { return *this; }
126     _LIBCPP_HIDE_FROM_ABI constexpr iterator operator++(int) { return *this; }
127   };
128 
129   _LIBCPP_HIDE_FROM_ABI constexpr __arg_t arg(size_t __id) const {
130     if (__id >= __size_)
131       std::__throw_format_error("The argument index value is too large for the number of arguments supplied");
132     return __args_[__id];
133   }
134 
135   _LIBCPP_HIDE_FROM_ABI constexpr const __compile_time_handle<_CharT>& __handle(size_t __id) const {
136     if (__id >= __size_)
137       std::__throw_format_error("The argument index value is too large for the number of arguments supplied");
138     return __handles_[__id];
139   }
140 
141   _LIBCPP_HIDE_FROM_ABI constexpr iterator out() { return {}; }
142   _LIBCPP_HIDE_FROM_ABI constexpr void advance_to(iterator) {}
143 
144 private:
145   const __arg_t* __args_;
146   const __compile_time_handle<_CharT>* __handles_;
147   size_t __size_;
148 };
149 
150 // [format.string.std]/8
151 // If { arg-idopt } is used in a width or precision, the value of the
152 // corresponding formatting argument is used in its place. If the
153 // corresponding formatting argument is not of standard signed or unsigned
154 // integer type, or its value is negative for precision or non-positive for
155 // width, an exception of type format_error is thrown.
156 //
157 // _HasPrecision does the formatter have a precision?
158 template <class _CharT, class _Tp, bool _HasPrecision = false>
159 _LIBCPP_HIDE_FROM_ABI constexpr void __compile_time_validate_argument(
160     basic_format_parse_context<_CharT>& __parse_ctx, __compile_time_basic_format_context<_CharT>& __ctx) {
161   auto __validate_type = [](__arg_t __type) {
162     // LWG3720 originally allowed "signed or unsigned integer types", however
163     // the final version explicitly changed it to "*standard* signed or unsigned
164     // integer types". It's trivial to use 128-bit integrals in libc++'s
165     // implementation, but other implementations may not implement it.
166     // (Using a width or precision, that does not fit in 64-bits, sounds very
167     // unlikely in real world code.)
168     switch (__type) {
169     case __arg_t::__int:
170     case __arg_t::__long_long:
171     case __arg_t::__unsigned:
172     case __arg_t::__unsigned_long_long:
173       return;
174 
175     default:
176       std::__throw_format_error("Replacement argument isn't a standard signed or unsigned integer type");
177     }
178   };
179 
180   formatter<_Tp, _CharT> __formatter;
181   __parse_ctx.advance_to(__formatter.parse(__parse_ctx));
182   if (__formatter.__parser_.__width_as_arg_)
183     __validate_type(__ctx.arg(__formatter.__parser_.__width_));
184 
185   if constexpr (_HasPrecision)
186     if (__formatter.__parser_.__precision_as_arg_)
187       __validate_type(__ctx.arg(__formatter.__parser_.__precision_));
188 }
189 
190 // This function is not user facing, so it can directly use the non-standard types of the "variant".
191 template <class _CharT>
192 _LIBCPP_HIDE_FROM_ABI constexpr void __compile_time_visit_format_arg(
193     basic_format_parse_context<_CharT>& __parse_ctx,
194     __compile_time_basic_format_context<_CharT>& __ctx,
195     __arg_t __type) {
196   switch (__type) {
197   case __arg_t::__none:
198     std::__throw_format_error("Invalid argument");
199   case __arg_t::__boolean:
200     return __format::__compile_time_validate_argument<_CharT, bool>(__parse_ctx, __ctx);
201   case __arg_t::__char_type:
202     return __format::__compile_time_validate_argument<_CharT, _CharT>(__parse_ctx, __ctx);
203   case __arg_t::__int:
204     return __format::__compile_time_validate_argument<_CharT, int>(__parse_ctx, __ctx);
205   case __arg_t::__long_long:
206     return __format::__compile_time_validate_argument<_CharT, long long>(__parse_ctx, __ctx);
207   case __arg_t::__i128:
208 #  if _LIBCPP_HAS_INT128
209     return __format::__compile_time_validate_argument<_CharT, __int128_t>(__parse_ctx, __ctx);
210 #  else
211     std::__throw_format_error("Invalid argument");
212 #  endif
213     return;
214   case __arg_t::__unsigned:
215     return __format::__compile_time_validate_argument<_CharT, unsigned>(__parse_ctx, __ctx);
216   case __arg_t::__unsigned_long_long:
217     return __format::__compile_time_validate_argument<_CharT, unsigned long long>(__parse_ctx, __ctx);
218   case __arg_t::__u128:
219 #  if _LIBCPP_HAS_INT128
220     return __format::__compile_time_validate_argument<_CharT, __uint128_t>(__parse_ctx, __ctx);
221 #  else
222     std::__throw_format_error("Invalid argument");
223 #  endif
224     return;
225   case __arg_t::__float:
226     return __format::__compile_time_validate_argument<_CharT, float, true>(__parse_ctx, __ctx);
227   case __arg_t::__double:
228     return __format::__compile_time_validate_argument<_CharT, double, true>(__parse_ctx, __ctx);
229   case __arg_t::__long_double:
230     return __format::__compile_time_validate_argument<_CharT, long double, true>(__parse_ctx, __ctx);
231   case __arg_t::__const_char_type_ptr:
232     return __format::__compile_time_validate_argument<_CharT, const _CharT*, true>(__parse_ctx, __ctx);
233   case __arg_t::__string_view:
234     return __format::__compile_time_validate_argument<_CharT, basic_string_view<_CharT>, true>(__parse_ctx, __ctx);
235   case __arg_t::__ptr:
236     return __format::__compile_time_validate_argument<_CharT, const void*>(__parse_ctx, __ctx);
237   case __arg_t::__handle:
238     std::__throw_format_error("Handle should use __compile_time_validate_handle_argument");
239   }
240   std::__throw_format_error("Invalid argument");
241 }
242 
243 template <contiguous_iterator _Iterator, class _ParseCtx, class _Ctx>
244 _LIBCPP_HIDE_FROM_ABI constexpr _Iterator
245 __handle_replacement_field(_Iterator __begin, _Iterator __end, _ParseCtx& __parse_ctx, _Ctx& __ctx) {
246   using _CharT                        = iter_value_t<_Iterator>;
247   __format::__parse_number_result __r = __format::__parse_arg_id(__begin, __end, __parse_ctx);
248 
249   if (__r.__last == __end)
250     std::__throw_format_error("The argument index should end with a ':' or a '}'");
251 
252   bool __parse = *__r.__last == _CharT(':');
253   switch (*__r.__last) {
254   case _CharT(':'):
255     // The arg-id has a format-specifier, advance the input to the format-spec.
256     __parse_ctx.advance_to(__r.__last + 1);
257     break;
258   case _CharT('}'):
259     // The arg-id has no format-specifier.
260     __parse_ctx.advance_to(__r.__last);
261     break;
262   default:
263     std::__throw_format_error("The argument index should end with a ':' or a '}'");
264   }
265 
266   if constexpr (same_as<_Ctx, __compile_time_basic_format_context<_CharT>>) {
267     __arg_t __type = __ctx.arg(__r.__value);
268     if (__type == __arg_t::__none)
269       std::__throw_format_error("The argument index value is too large for the number of arguments supplied");
270     else if (__type == __arg_t::__handle)
271       __ctx.__handle(__r.__value).__parse(__parse_ctx);
272     else if (__parse)
273       __format::__compile_time_visit_format_arg(__parse_ctx, __ctx, __type);
274   } else
275     std::__visit_format_arg(
276         [&](auto __arg) {
277           if constexpr (same_as<decltype(__arg), monostate>)
278             std::__throw_format_error("The argument index value is too large for the number of arguments supplied");
279           else if constexpr (same_as<decltype(__arg), typename basic_format_arg<_Ctx>::handle>)
280             __arg.format(__parse_ctx, __ctx);
281           else {
282             formatter<decltype(__arg), _CharT> __formatter;
283             if (__parse)
284               __parse_ctx.advance_to(__formatter.parse(__parse_ctx));
285             __ctx.advance_to(__formatter.format(__arg, __ctx));
286           }
287         },
288         __ctx.arg(__r.__value));
289 
290   __begin = __parse_ctx.begin();
291   if (__begin == __end || *__begin != _CharT('}'))
292     std::__throw_format_error("The replacement field misses a terminating '}'");
293 
294   return ++__begin;
295 }
296 
297 template <class _ParseCtx, class _Ctx>
298 _LIBCPP_HIDE_FROM_ABI constexpr typename _Ctx::iterator __vformat_to(_ParseCtx&& __parse_ctx, _Ctx&& __ctx) {
299   using _CharT = typename _ParseCtx::char_type;
300   static_assert(same_as<typename _Ctx::char_type, _CharT>);
301 
302   auto __begin                     = __parse_ctx.begin();
303   auto __end                       = __parse_ctx.end();
304   typename _Ctx::iterator __out_it = __ctx.out();
305   while (__begin != __end) {
306     switch (*__begin) {
307     case _CharT('{'):
308       ++__begin;
309       if (__begin == __end)
310         std::__throw_format_error("The format string terminates at a '{'");
311 
312       if (*__begin != _CharT('{')) [[likely]] {
313         __ctx.advance_to(std::move(__out_it));
314         __begin  = __format::__handle_replacement_field(__begin, __end, __parse_ctx, __ctx);
315         __out_it = __ctx.out();
316 
317         // The output is written and __begin points to the next character. So
318         // start the next iteration.
319         continue;
320       }
321       // The string is an escape character.
322       break;
323 
324     case _CharT('}'):
325       ++__begin;
326       if (__begin == __end || *__begin != _CharT('}'))
327         std::__throw_format_error("The format string contains an invalid escape sequence");
328 
329       break;
330     }
331 
332     // Copy the character to the output verbatim.
333     *__out_it++ = *__begin++;
334   }
335   return __out_it;
336 }
337 
338 } // namespace __format
339 
340 #  if _LIBCPP_STD_VER >= 26
341 template <class _CharT>
342 struct _LIBCPP_TEMPLATE_VIS __runtime_format_string {
343 private:
344   basic_string_view<_CharT> __str_;
345 
346   template <class _Cp, class... _Args>
347   friend struct _LIBCPP_TEMPLATE_VIS basic_format_string;
348 
349 public:
350   _LIBCPP_HIDE_FROM_ABI __runtime_format_string(basic_string_view<_CharT> __s) noexcept : __str_(__s) {}
351 
352   __runtime_format_string(const __runtime_format_string&)            = delete;
353   __runtime_format_string& operator=(const __runtime_format_string&) = delete;
354 };
355 
356 _LIBCPP_HIDE_FROM_ABI inline __runtime_format_string<char> runtime_format(string_view __fmt) noexcept { return __fmt; }
357 #    if _LIBCPP_HAS_WIDE_CHARACTERS
358 _LIBCPP_HIDE_FROM_ABI inline __runtime_format_string<wchar_t> runtime_format(wstring_view __fmt) noexcept {
359   return __fmt;
360 }
361 #    endif
362 #  endif // _LIBCPP_STD_VER >= 26
363 
364 template <class _CharT, class... _Args>
365 struct _LIBCPP_TEMPLATE_VIS basic_format_string {
366   template <class _Tp>
367     requires convertible_to<const _Tp&, basic_string_view<_CharT>>
368   consteval basic_format_string(const _Tp& __str) : __str_{__str} {
369     __format::__vformat_to(basic_format_parse_context<_CharT>{__str_, sizeof...(_Args)},
370                            _Context{__types_.data(), __handles_.data(), sizeof...(_Args)});
371   }
372 
373   _LIBCPP_HIDE_FROM_ABI constexpr basic_string_view<_CharT> get() const noexcept { return __str_; }
374 #  if _LIBCPP_STD_VER >= 26
375   _LIBCPP_HIDE_FROM_ABI basic_format_string(__runtime_format_string<_CharT> __s) noexcept : __str_(__s.__str_) {}
376 #  endif
377 
378 private:
379   basic_string_view<_CharT> __str_;
380 
381   using _Context _LIBCPP_NODEBUG = __format::__compile_time_basic_format_context<_CharT>;
382 
383   static constexpr array<__format::__arg_t, sizeof...(_Args)> __types_{
384       __format::__determine_arg_t<_Context, remove_cvref_t<_Args>>()...};
385 
386   static constexpr array<__format::__compile_time_handle<_CharT>, sizeof...(_Args)> __handles_{[] {
387     using _Tp = remove_cvref_t<_Args>;
388     __format::__compile_time_handle<_CharT> __handle;
389     if (__format::__determine_arg_t<_Context, _Tp>() == __format::__arg_t::__handle)
390       __handle.template __enable<_Tp>();
391 
392     return __handle;
393   }()...};
394 };
395 
396 template <class... _Args>
397 using format_string = basic_format_string<char, type_identity_t<_Args>...>;
398 
399 #  if _LIBCPP_HAS_WIDE_CHARACTERS
400 template <class... _Args>
401 using wformat_string = basic_format_string<wchar_t, type_identity_t<_Args>...>;
402 #  endif
403 
404 template <class _OutIt, class _CharT, class _FormatOutIt>
405   requires(output_iterator<_OutIt, const _CharT&>)
406 _LIBCPP_HIDE_FROM_ABI _OutIt __vformat_to(_OutIt __out_it,
407                                           basic_string_view<_CharT> __fmt,
408                                           basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
409   if constexpr (same_as<_OutIt, _FormatOutIt>)
410     return std::__format::__vformat_to(
411         basic_format_parse_context{__fmt, __args.__size()}, std::__format_context_create(std::move(__out_it), __args));
412   else {
413     typename __format::__buffer_selector<_OutIt, _CharT>::type __buffer{std::move(__out_it)};
414     std::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
415                                 std::__format_context_create(__buffer.__make_output_iterator(), __args));
416     return std::move(__buffer).__out_it();
417   }
418 }
419 
420 // The function is _LIBCPP_ALWAYS_INLINE since the compiler is bad at inlining
421 // https://reviews.llvm.org/D110499#inline-1180704
422 // TODO FMT Evaluate whether we want to file a Clang bug report regarding this.
423 template <output_iterator<const char&> _OutIt>
424 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt vformat_to(_OutIt __out_it, string_view __fmt, format_args __args) {
425   return std::__vformat_to(std::move(__out_it), __fmt, __args);
426 }
427 
428 #  if _LIBCPP_HAS_WIDE_CHARACTERS
429 template <output_iterator<const wchar_t&> _OutIt>
430 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
431 vformat_to(_OutIt __out_it, wstring_view __fmt, wformat_args __args) {
432   return std::__vformat_to(std::move(__out_it), __fmt, __args);
433 }
434 #  endif
435 
436 template <output_iterator<const char&> _OutIt, class... _Args>
437 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
438 format_to(_OutIt __out_it, format_string<_Args...> __fmt, _Args&&... __args) {
439   return std::vformat_to(std::move(__out_it), __fmt.get(), std::make_format_args(__args...));
440 }
441 
442 #  if _LIBCPP_HAS_WIDE_CHARACTERS
443 template <output_iterator<const wchar_t&> _OutIt, class... _Args>
444 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
445 format_to(_OutIt __out_it, wformat_string<_Args...> __fmt, _Args&&... __args) {
446   return std::vformat_to(std::move(__out_it), __fmt.get(), std::make_wformat_args(__args...));
447 }
448 #  endif
449 
450 // TODO FMT This needs to be a template or std::to_chars(floating-point) availability markup
451 // fires too eagerly, see http://llvm.org/PR61563.
452 template <class = void>
453 [[nodiscard]] _LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI string vformat(string_view __fmt, format_args __args) {
454   __format::__allocating_buffer<char> __buffer;
455   std::vformat_to(__buffer.__make_output_iterator(), __fmt, __args);
456   return string{__buffer.__view()};
457 }
458 
459 #  if _LIBCPP_HAS_WIDE_CHARACTERS
460 // TODO FMT This needs to be a template or std::to_chars(floating-point) availability markup
461 // fires too eagerly, see http://llvm.org/PR61563.
462 template <class = void>
463 [[nodiscard]] _LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI wstring
464 vformat(wstring_view __fmt, wformat_args __args) {
465   __format::__allocating_buffer<wchar_t> __buffer;
466   std::vformat_to(__buffer.__make_output_iterator(), __fmt, __args);
467   return wstring{__buffer.__view()};
468 }
469 #  endif
470 
471 template <class... _Args>
472 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI string
473 format(format_string<_Args...> __fmt, _Args&&... __args) {
474   return std::vformat(__fmt.get(), std::make_format_args(__args...));
475 }
476 
477 #  if _LIBCPP_HAS_WIDE_CHARACTERS
478 template <class... _Args>
479 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI wstring
480 format(wformat_string<_Args...> __fmt, _Args&&... __args) {
481   return std::vformat(__fmt.get(), std::make_wformat_args(__args...));
482 }
483 #  endif
484 
485 template <class _Context, class _OutIt, class _CharT>
486 _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt>
487 __vformat_to_n(_OutIt __out_it,
488                iter_difference_t<_OutIt> __n,
489                basic_string_view<_CharT> __fmt,
490                basic_format_args<_Context> __args) {
491   __format::__format_to_n_buffer<_OutIt, _CharT> __buffer{std::move(__out_it), __n};
492   std::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
493                               std::__format_context_create(__buffer.__make_output_iterator(), __args));
494   return std::move(__buffer).__result();
495 }
496 
497 template <output_iterator<const char&> _OutIt, class... _Args>
498 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt>
499 format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, format_string<_Args...> __fmt, _Args&&... __args) {
500   return std::__vformat_to_n<format_context>(std::move(__out_it), __n, __fmt.get(), std::make_format_args(__args...));
501 }
502 
503 #  if _LIBCPP_HAS_WIDE_CHARACTERS
504 template <output_iterator<const wchar_t&> _OutIt, class... _Args>
505 _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt>
506 format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, wformat_string<_Args...> __fmt, _Args&&... __args) {
507   return std::__vformat_to_n<wformat_context>(std::move(__out_it), __n, __fmt.get(), std::make_wformat_args(__args...));
508 }
509 #  endif
510 
511 template <class _CharT>
512 _LIBCPP_HIDE_FROM_ABI size_t __vformatted_size(basic_string_view<_CharT> __fmt, auto __args) {
513   __format::__formatted_size_buffer<_CharT> __buffer;
514   std::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
515                               std::__format_context_create(__buffer.__make_output_iterator(), __args));
516   return std::move(__buffer).__result();
517 }
518 
519 template <class... _Args>
520 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI size_t
521 formatted_size(format_string<_Args...> __fmt, _Args&&... __args) {
522   return std::__vformatted_size(__fmt.get(), basic_format_args{std::make_format_args(__args...)});
523 }
524 
525 #  if _LIBCPP_HAS_WIDE_CHARACTERS
526 template <class... _Args>
527 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI size_t
528 formatted_size(wformat_string<_Args...> __fmt, _Args&&... __args) {
529   return std::__vformatted_size(__fmt.get(), basic_format_args{std::make_wformat_args(__args...)});
530 }
531 #  endif
532 
533 #  if _LIBCPP_HAS_LOCALIZATION
534 
535 template <class _OutIt, class _CharT, class _FormatOutIt>
536   requires(output_iterator<_OutIt, const _CharT&>)
537 _LIBCPP_HIDE_FROM_ABI _OutIt __vformat_to(
538     _OutIt __out_it,
539     locale __loc,
540     basic_string_view<_CharT> __fmt,
541     basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
542   if constexpr (same_as<_OutIt, _FormatOutIt>)
543     return std::__format::__vformat_to(basic_format_parse_context{__fmt, __args.__size()},
544                                        std::__format_context_create(std::move(__out_it), __args, std::move(__loc)));
545   else {
546     typename __format::__buffer_selector<_OutIt, _CharT>::type __buffer{std::move(__out_it)};
547     std::__format::__vformat_to(
548         basic_format_parse_context{__fmt, __args.__size()},
549         std::__format_context_create(__buffer.__make_output_iterator(), __args, std::move(__loc)));
550     return std::move(__buffer).__out_it();
551   }
552 }
553 
554 template <output_iterator<const char&> _OutIt>
555 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
556 vformat_to(_OutIt __out_it, locale __loc, string_view __fmt, format_args __args) {
557   return std::__vformat_to(std::move(__out_it), std::move(__loc), __fmt, __args);
558 }
559 
560 #    if _LIBCPP_HAS_WIDE_CHARACTERS
561 template <output_iterator<const wchar_t&> _OutIt>
562 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
563 vformat_to(_OutIt __out_it, locale __loc, wstring_view __fmt, wformat_args __args) {
564   return std::__vformat_to(std::move(__out_it), std::move(__loc), __fmt, __args);
565 }
566 #    endif
567 
568 template <output_iterator<const char&> _OutIt, class... _Args>
569 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
570 format_to(_OutIt __out_it, locale __loc, format_string<_Args...> __fmt, _Args&&... __args) {
571   return std::vformat_to(std::move(__out_it), std::move(__loc), __fmt.get(), std::make_format_args(__args...));
572 }
573 
574 #    if _LIBCPP_HAS_WIDE_CHARACTERS
575 template <output_iterator<const wchar_t&> _OutIt, class... _Args>
576 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _OutIt
577 format_to(_OutIt __out_it, locale __loc, wformat_string<_Args...> __fmt, _Args&&... __args) {
578   return std::vformat_to(std::move(__out_it), std::move(__loc), __fmt.get(), std::make_wformat_args(__args...));
579 }
580 #    endif
581 
582 // TODO FMT This needs to be a template or std::to_chars(floating-point) availability markup
583 // fires too eagerly, see http://llvm.org/PR61563.
584 template <class = void>
585 [[nodiscard]] _LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI string
586 vformat(locale __loc, string_view __fmt, format_args __args) {
587   __format::__allocating_buffer<char> __buffer;
588   std::vformat_to(__buffer.__make_output_iterator(), std::move(__loc), __fmt, __args);
589   return string{__buffer.__view()};
590 }
591 
592 #    if _LIBCPP_HAS_WIDE_CHARACTERS
593 // TODO FMT This needs to be a template or std::to_chars(floating-point) availability markup
594 // fires too eagerly, see http://llvm.org/PR61563.
595 template <class = void>
596 [[nodiscard]] _LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI wstring
597 vformat(locale __loc, wstring_view __fmt, wformat_args __args) {
598   __format::__allocating_buffer<wchar_t> __buffer;
599   std::vformat_to(__buffer.__make_output_iterator(), std::move(__loc), __fmt, __args);
600   return wstring{__buffer.__view()};
601 }
602 #    endif
603 
604 template <class... _Args>
605 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI string
606 format(locale __loc, format_string<_Args...> __fmt, _Args&&... __args) {
607   return std::vformat(std::move(__loc), __fmt.get(), std::make_format_args(__args...));
608 }
609 
610 #    if _LIBCPP_HAS_WIDE_CHARACTERS
611 template <class... _Args>
612 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI wstring
613 format(locale __loc, wformat_string<_Args...> __fmt, _Args&&... __args) {
614   return std::vformat(std::move(__loc), __fmt.get(), std::make_wformat_args(__args...));
615 }
616 #    endif
617 
618 template <class _Context, class _OutIt, class _CharT>
619 _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt> __vformat_to_n(
620     _OutIt __out_it,
621     iter_difference_t<_OutIt> __n,
622     locale __loc,
623     basic_string_view<_CharT> __fmt,
624     basic_format_args<_Context> __args) {
625   __format::__format_to_n_buffer<_OutIt, _CharT> __buffer{std::move(__out_it), __n};
626   std::__format::__vformat_to(
627       basic_format_parse_context{__fmt, __args.__size()},
628       std::__format_context_create(__buffer.__make_output_iterator(), __args, std::move(__loc)));
629   return std::move(__buffer).__result();
630 }
631 
632 template <output_iterator<const char&> _OutIt, class... _Args>
633 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt> format_to_n(
634     _OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc, format_string<_Args...> __fmt, _Args&&... __args) {
635   return std::__vformat_to_n<format_context>(
636       std::move(__out_it), __n, std::move(__loc), __fmt.get(), std::make_format_args(__args...));
637 }
638 
639 #    if _LIBCPP_HAS_WIDE_CHARACTERS
640 template <output_iterator<const wchar_t&> _OutIt, class... _Args>
641 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI format_to_n_result<_OutIt> format_to_n(
642     _OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc, wformat_string<_Args...> __fmt, _Args&&... __args) {
643   return std::__vformat_to_n<wformat_context>(
644       std::move(__out_it), __n, std::move(__loc), __fmt.get(), std::make_wformat_args(__args...));
645 }
646 #    endif
647 
648 template <class _CharT>
649 _LIBCPP_HIDE_FROM_ABI size_t __vformatted_size(locale __loc, basic_string_view<_CharT> __fmt, auto __args) {
650   __format::__formatted_size_buffer<_CharT> __buffer;
651   std::__format::__vformat_to(
652       basic_format_parse_context{__fmt, __args.__size()},
653       std::__format_context_create(__buffer.__make_output_iterator(), __args, std::move(__loc)));
654   return std::move(__buffer).__result();
655 }
656 
657 template <class... _Args>
658 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI size_t
659 formatted_size(locale __loc, format_string<_Args...> __fmt, _Args&&... __args) {
660   return std::__vformatted_size(std::move(__loc), __fmt.get(), basic_format_args{std::make_format_args(__args...)});
661 }
662 
663 #    if _LIBCPP_HAS_WIDE_CHARACTERS
664 template <class... _Args>
665 [[nodiscard]] _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI size_t
666 formatted_size(locale __loc, wformat_string<_Args...> __fmt, _Args&&... __args) {
667   return std::__vformatted_size(std::move(__loc), __fmt.get(), basic_format_args{std::make_wformat_args(__args...)});
668 }
669 #    endif
670 
671 #  endif // _LIBCPP_HAS_LOCALIZATION
672 
673 #endif // _LIBCPP_STD_VER >= 20
674 
675 _LIBCPP_END_NAMESPACE_STD
676 
677 _LIBCPP_POP_MACROS
678 
679 #endif // _LIBCPP___FORMAT_FORMAT_FUNCTIONS
680