aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/cxxsupp/libcxx/include/format
blob: 4cf146ead17a253ad70098942dbcf0130dce4a52 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_FORMAT
#define _LIBCPP_FORMAT

/*

namespace std {
  // [format.context], class template basic_format_context
  template<class Out, class charT> class basic_format_context;
  using format_context = basic_format_context<unspecified, char>;
  using wformat_context = basic_format_context<unspecified, wchar_t>;

  // [format.args], class template basic_format_args
  template<class Context> class basic_format_args;
  using format_args = basic_format_args<format_context>;
  using wformat_args = basic_format_args<wformat_context>;

  // [format.functions], formatting functions
  template<class... Args>
    string format(string_view fmt, const Args&... args);
  template<class... Args>
    wstring format(wstring_view fmt, const Args&... args);
  template<class... Args>
    string format(const locale& loc, string_view fmt, const Args&... args);
  template<class... Args>
    wstring format(const locale& loc, wstring_view fmt, const Args&... args);

  string vformat(string_view fmt, format_args args);
  wstring vformat(wstring_view fmt, wformat_args args);
  string vformat(const locale& loc, string_view fmt, format_args args);
  wstring vformat(const locale& loc, wstring_view fmt, wformat_args args);

  template<class Out, class... Args>
    Out format_to(Out out, string_view fmt, const Args&... args);
  template<class Out, class... Args>
    Out format_to(Out out, wstring_view fmt, const Args&... args);
  template<class Out, class... Args>
    Out format_to(Out out, const locale& loc, string_view fmt, const Args&... args);
  template<class Out, class... Args>
    Out format_to(Out out, const locale& loc, wstring_view fmt, const Args&... args);

  template<class Out>
    Out vformat_to(Out out, string_view fmt, format_args args);
  template<class Out>
    Out vformat_to(Out out, wstring_view fmt, wformat_args args);
  template<class Out>
    Out vformat_to(Out out, const locale& loc, string_view fmt,
                   format_args char> args);
  template<class Out>
    Out vformat_to(Out out, const locale& loc, wstring_view fmt,
                   wformat_args args);

  template<class Out> struct format_to_n_result {
    Out out;
    iter_difference_t<Out> size;
  };
  template<class Out, class... Args>
    format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n,
                                        string_view fmt, const Args&... args);
  template<class Out, class... Args>
    format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n,
                                        wstring_view fmt, const Args&... args);
  template<class Out, class... Args>
    format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n,
                                        const locale& loc, string_view fmt,
                                        const Args&... args);
  template<class Out, class... Args>
    format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n,
                                        const locale& loc, wstring_view fmt,
                                        const Args&... args);

  template<class... Args>
    size_t formatted_size(string_view fmt, const Args&... args);
  template<class... Args>
    size_t formatted_size(wstring_view fmt, const Args&... args);
  template<class... Args>
    size_t formatted_size(const locale& loc, string_view fmt, const Args&... args);
  template<class... Args>
    size_t formatted_size(const locale& loc, wstring_view fmt, const Args&... args);

  // [format.formatter], formatter
  template<class T, class charT = char> struct formatter;

  // [format.parse.ctx], class template basic_format_parse_context
  template<class charT> class basic_format_parse_context;
  using format_parse_context = basic_format_parse_context<char>;
  using wformat_parse_context = basic_format_parse_context<wchar_t>;

  // [format.arguments], arguments
  // [format.arg], class template basic_format_arg
  template<class Context> class basic_format_arg;

  template<class Visitor, class Context>
    see below visit_format_arg(Visitor&& vis, basic_format_arg<Context> arg);

  // [format.arg.store], class template format-arg-store
  template<class Context, class... Args> struct format-arg-store;      // exposition only

  template<class Context = format_context, class... Args>
    format-arg-store<Context, Args...>
      make_format_args(const Args&... args);
  template<class... Args>
    format-arg-store<wformat_context, Args...>
      make_wformat_args(const Args&... args);

  // [format.error], class format_error
  class format_error;
}

*/

// Make sure all feature-test macros are available.
#include <version>
// Enable the contents of the header only when libc++ was built with LIBCXX_ENABLE_INCOMPLETE_FEATURES.
#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)

#include <__config>
#include <__debug>
#include <__format/format_arg.h>
#include <__format/format_args.h>
#include <__format/format_context.h>
#include <__format/format_error.h>
#include <__format/format_fwd.h>
#include <__format/format_parse_context.h>
#include <__format/format_string.h>
#include <__format/format_to_n_result.h>
#include <__format/formatter.h>
#include <__format/formatter_bool.h>
#include <__format/formatter_char.h>
#include <__format/formatter_floating_point.h>
#include <__format/formatter_integer.h>
#include <__format/formatter_pointer.h>
#include <__format/formatter_string.h>
#include <__format/parser_std_format_spec.h>
#include <__variant/monostate.h>
#include <array>
#include <concepts>
#include <string>
#include <string_view>
#include <type_traits>

#ifndef _LIBCPP_HAS_NO_LOCALIZATION
#include <locale>
#endif

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>

_LIBCPP_BEGIN_NAMESPACE_STD

#if _LIBCPP_STD_VER > 17

// TODO FMT Remove this once we require compilers with proper C++20 support.
// If the compiler has no concepts support, the format header will be disabled.
// Without concepts support enable_if needs to be used and that too much effort
// to support compilers with partial C++20 support.
#if !defined(_LIBCPP_HAS_NO_CONCEPTS)

// TODO FMT Move the implementation in this file to its own granular headers.

// TODO FMT Evaluate which templates should be external templates. This
// improves the efficiency of the header. However since the header is still
// under heavy development and not all classes are stable it makes no sense
// to do this optimization now.

using format_args = basic_format_args<format_context>;
#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
using wformat_args = basic_format_args<wformat_context>;
#endif

template <class _Context, class... _Args>
struct _LIBCPP_TEMPLATE_VIS __format_arg_store {
  // TODO FMT Use a built-in array.
  array<basic_format_arg<_Context>, sizeof...(_Args)> __args;
};

template <class _Context = format_context, class... _Args>
_LIBCPP_HIDE_FROM_ABI __format_arg_store<_Context, _Args...>
make_format_args(const _Args&... __args) {
  return {basic_format_arg<_Context>(__args)...};
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI __format_arg_store<wformat_context, _Args...>
make_wformat_args(const _Args&... __args) {
  return _VSTD::make_format_args<wformat_context>(__args...);
}
#endif

namespace __format {

template <class _CharT, class _ParseCtx, class _Ctx>
_LIBCPP_HIDE_FROM_ABI const _CharT*
__handle_replacement_field(const _CharT* __begin, const _CharT* __end,
                           _ParseCtx& __parse_ctx, _Ctx& __ctx) {
  __format::__parse_number_result __r =
      __format::__parse_arg_id(__begin, __end, __parse_ctx);

  switch (*__r.__ptr) {
  case _CharT(':'):
    // The arg-id has a format-specifier, advance the input to the format-spec.
    __parse_ctx.advance_to(__r.__ptr + 1);
    break;
  case _CharT('}'):
    // The arg-id has no format-specifier.
    __parse_ctx.advance_to(__r.__ptr);
    break;
  default:
    __throw_format_error(
        "The replacement field arg-id should terminate at a ':' or '}'");
  }

  _VSTD::visit_format_arg(
      [&](auto __arg) {
        if constexpr (same_as<decltype(__arg), monostate>)
          __throw_format_error("Argument index out of bounds");
        else if constexpr (same_as<decltype(__arg), typename basic_format_arg<_Ctx>::handle>)
          __arg.format(__parse_ctx, __ctx);
        else {
          formatter<decltype(__arg), _CharT> __formatter;
          __parse_ctx.advance_to(__formatter.parse(__parse_ctx));
          __ctx.advance_to(__formatter.format(__arg, __ctx));
        }
      },
      __ctx.arg(__r.__value));

  __begin = __parse_ctx.begin();
  if (__begin == __end || *__begin != _CharT('}'))
    __throw_format_error("The replacement field misses a terminating '}'");

  return ++__begin;
}

template <class _ParseCtx, class _Ctx>
_LIBCPP_HIDE_FROM_ABI typename _Ctx::iterator
__vformat_to(_ParseCtx&& __parse_ctx, _Ctx&& __ctx) {
  using _CharT = typename _ParseCtx::char_type;
  static_assert(same_as<typename _Ctx::char_type, _CharT>);

  const _CharT* __begin = __parse_ctx.begin();
  const _CharT* __end = __parse_ctx.end();
  typename _Ctx::iterator __out_it = __ctx.out();
  while (__begin != __end) {
    switch (*__begin) {
    case _CharT('{'):
      ++__begin;
      if (__begin == __end)
        __throw_format_error("The format string terminates at a '{'");

      if (*__begin != _CharT('{')) [[likely]] {
        __ctx.advance_to(_VSTD::move(__out_it));
        __begin =
            __handle_replacement_field(__begin, __end, __parse_ctx, __ctx);
        __out_it = __ctx.out();

        // The output is written and __begin points to the next character. So
        // start the next iteration.
        continue;
      }
      // The string is an escape character.
      break;

    case _CharT('}'):
      ++__begin;
      if (__begin == __end || *__begin != _CharT('}'))
        __throw_format_error(
            "The format string contains an invalid escape sequence");

      break;
    }

    // Copy the character to the output verbatim.
    *__out_it++ = *__begin++;
  }
  return __out_it;
}

} // namespace __format

template <class _OutIt, class _CharT, class _FormatOutIt>
requires(output_iterator<_OutIt, const _CharT&>) _LIBCPP_HIDE_FROM_ABI _OutIt
    __vformat_to(
        _OutIt __out_it, basic_string_view<_CharT> __fmt,
        basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
  if constexpr (same_as<_OutIt, _FormatOutIt>)
    return _VSTD::__format::__vformat_to(
        basic_format_parse_context{__fmt, __args.__size()},
        _VSTD::__format_context_create(_VSTD::move(__out_it), __args));
  else {
    basic_string<_CharT> __str;
    _VSTD::__format::__vformat_to(
        basic_format_parse_context{__fmt, __args.__size()},
        _VSTD::__format_context_create(_VSTD::back_inserter(__str), __args));
    return _VSTD::copy_n(__str.begin(), __str.size(), _VSTD::move(__out_it));
  }
}

template <output_iterator<const char&> _OutIt>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt
vformat_to(_OutIt __out_it, string_view __fmt, format_args __args) {
  return _VSTD::__vformat_to(_VSTD::move(__out_it), __fmt, __args);
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <output_iterator<const wchar_t&> _OutIt>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt
vformat_to(_OutIt __out_it, wstring_view __fmt, wformat_args __args) {
  return _VSTD::__vformat_to(_VSTD::move(__out_it), __fmt, __args);
}
#endif

template <output_iterator<const char&> _OutIt, class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt
format_to(_OutIt __out_it, string_view __fmt, const _Args&... __args) {
  return _VSTD::vformat_to(_VSTD::move(__out_it), __fmt,
                           _VSTD::make_format_args(__args...));
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <output_iterator<const wchar_t&> _OutIt, class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt
format_to(_OutIt __out_it, wstring_view __fmt, const _Args&... __args) {
  return _VSTD::vformat_to(_VSTD::move(__out_it), __fmt,
                           _VSTD::make_wformat_args(__args...));
}
#endif

_LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
vformat(string_view __fmt, format_args __args) {
  string __res;
  _VSTD::vformat_to(_VSTD::back_inserter(__res), __fmt, __args);
  return __res;
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
_LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
vformat(wstring_view __fmt, wformat_args __args) {
  wstring __res;
  _VSTD::vformat_to(_VSTD::back_inserter(__res), __fmt, __args);
  return __res;
}
#endif

template <class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
format(string_view __fmt, const _Args&... __args) {
  return _VSTD::vformat(__fmt, _VSTD::make_format_args(__args...));
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
format(wstring_view __fmt, const _Args&... __args) {
  return _VSTD::vformat(__fmt, _VSTD::make_wformat_args(__args...));
}
#endif

template <output_iterator<const char&> _OutIt, class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, string_view __fmt,
            const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  string __str = _VSTD::vformat(__fmt, _VSTD::make_format_args(__args...));
  iter_difference_t<_OutIt> __s = __str.size();
  iter_difference_t<_OutIt> __m =
      _VSTD::clamp(__n, iter_difference_t<_OutIt>(0), __s);
  __out_it = _VSTD::copy_n(__str.begin(), __m, _VSTD::move(__out_it));
  return {_VSTD::move(__out_it), __s};
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <output_iterator<const wchar_t&> _OutIt, class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, wstring_view __fmt,
            const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  wstring __str = _VSTD::vformat(__fmt, _VSTD::make_wformat_args(__args...));
  iter_difference_t<_OutIt> __s = __str.size();
  iter_difference_t<_OutIt> __m =
      _VSTD::clamp(__n, iter_difference_t<_OutIt>(0), __s);
  __out_it = _VSTD::copy_n(__str.begin(), __m, _VSTD::move(__out_it));
  return {_VSTD::move(__out_it), __s};
}
#endif

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
formatted_size(string_view __fmt, const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  return _VSTD::vformat(__fmt, _VSTD::make_format_args(__args...)).size();
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
formatted_size(wstring_view __fmt, const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  return _VSTD::vformat(__fmt, _VSTD::make_wformat_args(__args...)).size();
}
#endif

#ifndef _LIBCPP_HAS_NO_LOCALIZATION

template <class _OutIt, class _CharT, class _FormatOutIt>
requires(output_iterator<_OutIt, const _CharT&>) _LIBCPP_HIDE_FROM_ABI _OutIt
    __vformat_to(
        _OutIt __out_it, locale __loc, basic_string_view<_CharT> __fmt,
        basic_format_args<basic_format_context<_FormatOutIt, _CharT>> __args) {
  if constexpr (same_as<_OutIt, _FormatOutIt>)
    return _VSTD::__format::__vformat_to(
        basic_format_parse_context{__fmt, __args.__size()},
        _VSTD::__format_context_create(_VSTD::move(__out_it), __args,
                                       _VSTD::move(__loc)));
  else {
    basic_string<_CharT> __str;
    _VSTD::__format::__vformat_to(
        basic_format_parse_context{__fmt, __args.__size()},
        _VSTD::__format_context_create(_VSTD::back_inserter(__str), __args,
                                       _VSTD::move(__loc)));
    return _VSTD::copy_n(__str.begin(), __str.size(), _VSTD::move(__out_it));
  }
}

template <output_iterator<const char&> _OutIt>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt vformat_to(
    _OutIt __out_it, locale __loc, string_view __fmt, format_args __args) {
  return _VSTD::__vformat_to(_VSTD::move(__out_it), _VSTD::move(__loc), __fmt,
                             __args);
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <output_iterator<const wchar_t&> _OutIt>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt vformat_to(
    _OutIt __out_it, locale __loc, wstring_view __fmt, wformat_args __args) {
  return _VSTD::__vformat_to(_VSTD::move(__out_it), _VSTD::move(__loc), __fmt,
                             __args);
}
#endif

template <output_iterator<const char&> _OutIt, class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt format_to(
    _OutIt __out_it, locale __loc, string_view __fmt, const _Args&... __args) {
  return _VSTD::vformat_to(_VSTD::move(__out_it), _VSTD::move(__loc), __fmt,
                           _VSTD::make_format_args(__args...));
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <output_iterator<const wchar_t&> _OutIt, class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT _OutIt format_to(
    _OutIt __out_it, locale __loc, wstring_view __fmt, const _Args&... __args) {
  return _VSTD::vformat_to(_VSTD::move(__out_it), _VSTD::move(__loc), __fmt,
                           _VSTD::make_wformat_args(__args...));
}
#endif

_LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
vformat(locale __loc, string_view __fmt, format_args __args) {
  string __res;
  _VSTD::vformat_to(_VSTD::back_inserter(__res), _VSTD::move(__loc), __fmt,
                    __args);
  return __res;
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
_LIBCPP_ALWAYS_INLINE inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
vformat(locale __loc, wstring_view __fmt, wformat_args __args) {
  wstring __res;
  _VSTD::vformat_to(_VSTD::back_inserter(__res), _VSTD::move(__loc), __fmt,
                    __args);
  return __res;
}
#endif

template <class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT string
format(locale __loc, string_view __fmt, const _Args&... __args) {
  return _VSTD::vformat(_VSTD::move(__loc), __fmt,
                        _VSTD::make_format_args(__args...));
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class... _Args>
_LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT wstring
format(locale __loc, wstring_view __fmt, const _Args&... __args) {
  return _VSTD::vformat(_VSTD::move(__loc), __fmt,
                        _VSTD::make_wformat_args(__args...));
}
#endif

template <output_iterator<const char&> _OutIt, class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc,
            string_view __fmt, const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  string __str = _VSTD::vformat(_VSTD::move(__loc), __fmt,
                                _VSTD::make_format_args(__args...));
  iter_difference_t<_OutIt> __s = __str.size();
  iter_difference_t<_OutIt> __m =
      _VSTD::clamp(__n, iter_difference_t<_OutIt>(0), __s);
  __out_it = _VSTD::copy_n(__str.begin(), __m, _VSTD::move(__out_it));
  return {_VSTD::move(__out_it), __s};
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <output_iterator<const wchar_t&> _OutIt, class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT format_to_n_result<_OutIt>
format_to_n(_OutIt __out_it, iter_difference_t<_OutIt> __n, locale __loc,
            wstring_view __fmt, const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  wstring __str = _VSTD::vformat(_VSTD::move(__loc), __fmt,
                                 _VSTD::make_wformat_args(__args...));
  iter_difference_t<_OutIt> __s = __str.size();
  iter_difference_t<_OutIt> __m =
      _VSTD::clamp(__n, iter_difference_t<_OutIt>(0), __s);
  __out_it = _VSTD::copy_n(__str.begin(), __m, _VSTD::move(__out_it));
  return {_VSTD::move(__out_it), __s};
}
#endif

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
formatted_size(locale __loc, string_view __fmt, const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  return _VSTD::vformat(_VSTD::move(__loc), __fmt,
                        _VSTD::make_format_args(__args...))
      .size();
}

#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_FORMAT size_t
formatted_size(locale __loc, wstring_view __fmt, const _Args&... __args) {
  // TODO FMT Improve PoC: using std::string is inefficient.
  return _VSTD::vformat(_VSTD::move(__loc), __fmt,
                        _VSTD::make_wformat_args(__args...))
      .size();
}
#endif

#endif // _LIBCPP_HAS_NO_LOCALIZATION

#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
#endif //_LIBCPP_STD_VER > 17

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif // !defined(_LIBCPP_HAS_NO_INCOMPLETE_FORMAT)

#endif // _LIBCPP_FORMAT