libstdc++
format
Go to the documentation of this file.
1// <format> Formatting -*- C++ -*-
2
3// Copyright The GNU Toolchain Authors.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file include/format
26 * This is a Standard C++ Library header.
27 */
28
29#ifndef _GLIBCXX_FORMAT
30#define _GLIBCXX_FORMAT 1
31
32#ifdef _GLIBCXX_SYSHDR
33#pragma GCC system_header
34#endif
35
36#include <bits/requires_hosted.h> // for std::string
37
38#define __glibcxx_want_format
39#define __glibcxx_want_format_ranges
40#define __glibcxx_want_format_uchar
41#include <bits/version.h>
42
43#ifdef __cpp_lib_format // C++ >= 20 && HOSTED
44
45#include <array>
46#include <charconv>
47#include <concepts>
48#include <limits>
49#include <locale>
50#include <optional>
51#include <span>
52#include <string_view>
53#include <string>
54#include <bits/monostate.h>
55#include <bits/formatfwd.h>
56#include <bits/ranges_base.h> // input_range, range_reference_t
57#include <bits/ranges_util.h> // subrange
58#include <bits/ranges_algobase.h> // ranges::copy
59#include <bits/stl_iterator.h> // back_insert_iterator
60#include <bits/stl_pair.h> // __is_pair
61#include <bits/unicode.h> // __is_scalar_value, _Utf_view, etc.
62#include <bits/utility.h> // tuple_size_v
63#include <ext/numeric_traits.h> // __int_traits
64
65#if !__has_builtin(__builtin_toupper)
66# include <cctype>
67#endif
68
69#pragma GCC diagnostic push
70#pragma GCC diagnostic ignored "-Wpedantic" // __int128
71#pragma GCC diagnostic ignored "-Wc++23-extensions" // bf16
72
73namespace std _GLIBCXX_VISIBILITY(default)
74{
75_GLIBCXX_BEGIN_NAMESPACE_VERSION
76
77 // [format.fmt.string], class template basic_format_string
78 template<typename _CharT, typename... _Args> struct basic_format_string;
79
80/// @cond undocumented
81namespace __format
82{
83 // STATICALLY-WIDEN, see C++20 [time.general]
84 // It doesn't matter for format strings (which can only be char or wchar_t)
85 // but this returns the narrow string for anything that isn't wchar_t. This
86 // is done because const char* can be inserted into any ostream type, and
87 // will be widened at runtime if necessary.
88 template<typename _CharT>
89 consteval auto
90 _Widen(const char* __narrow, const wchar_t* __wide)
91 {
92 if constexpr (is_same_v<_CharT, wchar_t>)
93 return __wide;
94 else
95 return __narrow;
96 }
97#define _GLIBCXX_WIDEN_(C, S) ::std::__format::_Widen<C>(S, L##S)
98#define _GLIBCXX_WIDEN(S) _GLIBCXX_WIDEN_(_CharT, S)
99
100 // Size for stack located buffer
101 template<typename _CharT>
102 constexpr size_t __stackbuf_size = 32 * sizeof(void*) / sizeof(_CharT);
103
104 // Type-erased character sinks.
105 template<typename _CharT> class _Sink;
106 template<typename _CharT> class _Fixedbuf_sink;
107 template<typename _Seq> class _Seq_sink;
108
109 template<typename _CharT, typename _Alloc = allocator<_CharT>>
110 using _Str_sink
111 = _Seq_sink<basic_string<_CharT, char_traits<_CharT>, _Alloc>>;
112
113 // template<typename _CharT, typename _Alloc = allocator<_CharT>>
114 // using _Vec_sink = _Seq_sink<vector<_CharT, _Alloc>>;
115
116 // Output iterator that writes to a type-erase character sink.
117 template<typename _CharT>
118 class _Sink_iter;
119
120 // An unspecified output iterator type used in the `formattable` concept.
121 template<typename _CharT>
122 struct _Iter_for
123 { using type = back_insert_iterator<basic_string<_CharT>>; };
124
125 template<typename _CharT>
126 using __format_context = basic_format_context<_Sink_iter<_CharT>, _CharT>;
127
128 template<typename _CharT>
129 struct _Runtime_format_string
130 {
131 [[__gnu__::__always_inline__]]
132 _Runtime_format_string(basic_string_view<_CharT> __s) noexcept
133 : _M_str(__s) { }
134
135 _Runtime_format_string(const _Runtime_format_string&) = delete;
136 void operator=(const _Runtime_format_string&) = delete;
137
138 private:
139 basic_string_view<_CharT> _M_str;
140
141 template<typename, typename...> friend struct std::basic_format_string;
142 };
143
144} // namespace __format
145/// @endcond
146
147 using format_context = __format::__format_context<char>;
148#ifdef _GLIBCXX_USE_WCHAR_T
149 using wformat_context = __format::__format_context<wchar_t>;
150#endif
151
152 // [format.args], class template basic_format_args
153 template<typename _Context> class basic_format_args;
154 using format_args = basic_format_args<format_context>;
155#ifdef _GLIBCXX_USE_WCHAR_T
156 using wformat_args = basic_format_args<wformat_context>;
157#endif
158
159 // [format.arguments], arguments
160 // [format.arg], class template basic_format_arg
161 template<typename _Context>
162 class basic_format_arg;
163
164 /** A compile-time checked format string for the specified argument types.
165 *
166 * @since C++23 but available as an extension in C++20.
167 */
168 template<typename _CharT, typename... _Args>
169 struct basic_format_string
170 {
171 template<typename _Tp>
172 requires convertible_to<const _Tp&, basic_string_view<_CharT>>
173 consteval
174 basic_format_string(const _Tp& __s);
175
176 [[__gnu__::__always_inline__]]
177 basic_format_string(__format::_Runtime_format_string<_CharT> __s) noexcept
178 : _M_str(__s._M_str)
179 { }
180
181 [[__gnu__::__always_inline__]]
182 constexpr basic_string_view<_CharT>
183 get() const noexcept
184 { return _M_str; }
185
186 private:
187 basic_string_view<_CharT> _M_str;
188 };
189
190 template<typename... _Args>
191 using format_string = basic_format_string<char, type_identity_t<_Args>...>;
192
193#ifdef _GLIBCXX_USE_WCHAR_T
194 template<typename... _Args>
195 using wformat_string
196 = basic_format_string<wchar_t, type_identity_t<_Args>...>;
197#endif
198
199#if __cpp_lib_format >= 202311L // >= C++26
200 [[__gnu__::__always_inline__]]
201 inline __format::_Runtime_format_string<char>
202 runtime_format(string_view __fmt) noexcept
203 { return __fmt; }
204
205#ifdef _GLIBCXX_USE_WCHAR_T
206 [[__gnu__::__always_inline__]]
207 inline __format::_Runtime_format_string<wchar_t>
208 runtime_format(wstring_view __fmt) noexcept
209 { return __fmt; }
210#endif
211#endif // C++26
212
213 // [format.formatter], formatter
214
215 /// The primary template of std::formatter is disabled.
216 template<typename _Tp, typename _CharT>
217 struct formatter
218 {
219 formatter() = delete; // No std::formatter specialization for this type.
220 formatter(const formatter&) = delete;
221 formatter& operator=(const formatter&) = delete;
222 };
223
224 // [format.error], class format_error
225 class format_error : public runtime_error
226 {
227 public:
228 explicit format_error(const string& __what) : runtime_error(__what) { }
229 explicit format_error(const char* __what) : runtime_error(__what) { }
230 };
231
232 /// @cond undocumented
233 [[noreturn]]
234 inline void
235 __throw_format_error(const char* __what)
236 { _GLIBCXX_THROW_OR_ABORT(format_error(__what)); }
237
238namespace __format
239{
240 // XXX use named functions for each constexpr error?
241
242 [[noreturn]]
243 inline void
244 __unmatched_left_brace_in_format_string()
245 { __throw_format_error("format error: unmatched '{' in format string"); }
246
247 [[noreturn]]
248 inline void
249 __unmatched_right_brace_in_format_string()
250 { __throw_format_error("format error: unmatched '}' in format string"); }
251
252 [[noreturn]]
253 inline void
254 __conflicting_indexing_in_format_string()
255 { __throw_format_error("format error: conflicting indexing style in format string"); }
256
257 [[noreturn]]
258 inline void
259 __invalid_arg_id_in_format_string()
260 { __throw_format_error("format error: invalid arg-id in format string"); }
261
262 [[noreturn]]
263 inline void
264 __failed_to_parse_format_spec()
265 { __throw_format_error("format error: failed to parse format-spec"); }
266
267 template<typename _CharT> class _Scanner;
268
269} // namespace __format
270 /// @endcond
271
272 // [format.parse.ctx], class template basic_format_parse_context
273 template<typename _CharT> class basic_format_parse_context;
274 using format_parse_context = basic_format_parse_context<char>;
275#ifdef _GLIBCXX_USE_WCHAR_T
276 using wformat_parse_context = basic_format_parse_context<wchar_t>;
277#endif
278
279 template<typename _CharT>
280 class basic_format_parse_context
281 {
282 public:
283 using char_type = _CharT;
284 using const_iterator = typename basic_string_view<_CharT>::const_iterator;
285 using iterator = const_iterator;
286
287 constexpr explicit
288 basic_format_parse_context(basic_string_view<_CharT> __fmt) noexcept
289 : _M_begin(__fmt.begin()), _M_end(__fmt.end())
290 { }
291
292 basic_format_parse_context(const basic_format_parse_context&) = delete;
293 void operator=(const basic_format_parse_context&) = delete;
294
295 constexpr const_iterator begin() const noexcept { return _M_begin; }
296 constexpr const_iterator end() const noexcept { return _M_end; }
297
298 constexpr void
299 advance_to(const_iterator __it) noexcept
300 { _M_begin = __it; }
301
302 constexpr size_t
303 next_arg_id()
304 {
305 if (_M_indexing == _Manual)
306 __format::__conflicting_indexing_in_format_string();
307 _M_indexing = _Auto;
308
309 // _GLIBCXX_RESOLVE_LIB_DEFECTS
310 // 3825. Missing compile-time argument id check in next_arg_id
311 if (std::is_constant_evaluated())
312 if (_M_next_arg_id == _M_num_args)
313 __format::__invalid_arg_id_in_format_string();
314 return _M_next_arg_id++;
315 }
316
317 constexpr void
318 check_arg_id(size_t __id)
319 {
320 if (_M_indexing == _Auto)
321 __format::__conflicting_indexing_in_format_string();
322 _M_indexing = _Manual;
323
324 if (std::is_constant_evaluated())
325 if (__id >= _M_num_args)
326 __format::__invalid_arg_id_in_format_string();
327 }
328
329#if __cpp_lib_format >= 202305L
330 template<typename... _Ts>
331 constexpr void
332 check_dynamic_spec(size_t __id) noexcept
333 {
334 static_assert(__valid_types_for_check_dynamic_spec<_Ts...>(),
335 "template arguments for check_dynamic_spec<Ts...>(id) "
336 "must be unique and must be one of the allowed types");
337 if consteval {
338 __check_dynamic_spec<_Ts...>(__id);
339 }
340 }
341
342 constexpr void
343 check_dynamic_spec_integral(size_t __id) noexcept
344 {
345 if consteval {
346 __check_dynamic_spec<int, unsigned, long long,
347 unsigned long long>(__id);
348 }
349 }
350
351 constexpr void
352 check_dynamic_spec_string(size_t __id) noexcept
353 {
354 if consteval {
355 __check_dynamic_spec<const _CharT*, basic_string_view<_CharT>>(__id);
356 }
357 }
358
359 private:
360 // True if _Tp occurs exactly once in _Ts.
361 template<typename _Tp, typename... _Ts>
362 static constexpr bool __once = (is_same_v<_Tp, _Ts> + ...) == 1;
363
364 template<typename... _Ts>
365 consteval bool
366 __valid_types_for_check_dynamic_spec()
367 {
368 // _GLIBCXX_RESOLVE_LIB_DEFECTS
369 // 4142. check_dynamic_spec should require at least one type
370 if constexpr (sizeof...(_Ts) == 0)
371 return false;
372 else
373 {
374 // The types in Ts... are unique. Each type in Ts... is one of
375 // bool, char_type, int, unsigned int, long long int,
376 // unsigned long long int, float, double, long double,
377 // const char_type*, basic_string_view<char_type>, or const void*.
378 unsigned __sum
379 = __once<bool, _Ts...>
380 + __once<char_type, _Ts...>
381 + __once<int, _Ts...>
382 + __once<unsigned int, _Ts...>
383 + __once<long long int, _Ts...>
384 + __once<unsigned long long int, _Ts...>
385 + __once<float, _Ts...>
386 + __once<double, _Ts...>
387 + __once<long double, _Ts...>
388 + __once<const char_type*, _Ts...>
389 + __once<basic_string_view<char_type>, _Ts...>
390 + __once<const void*, _Ts...>;
391 return __sum == sizeof...(_Ts);
392 }
393 }
394
395 template<typename... _Ts>
396 consteval void
397 __check_dynamic_spec(size_t __id) noexcept;
398
399 // This must not be constexpr.
400 static void __invalid_dynamic_spec(const char*);
401
402 friend __format::_Scanner<_CharT>;
403#endif
404
405 // This constructor should only be used by the implementation.
406 constexpr explicit
407 basic_format_parse_context(basic_string_view<_CharT> __fmt,
408 size_t __num_args) noexcept
409 : _M_begin(__fmt.begin()), _M_end(__fmt.end()), _M_num_args(__num_args)
410 { }
411
412 private:
413 iterator _M_begin;
414 iterator _M_end;
415 enum _Indexing { _Unknown, _Manual, _Auto };
416 _Indexing _M_indexing = _Unknown;
417 size_t _M_next_arg_id = 0;
418 size_t _M_num_args = 0;
419 };
420
421/// @cond undocumented
422 template<typename _Tp, template<typename...> class _Class>
423 constexpr bool __is_specialization_of = false;
424 template<template<typename...> class _Class, typename... _Args>
425 constexpr bool __is_specialization_of<_Class<_Args...>, _Class> = true;
426
427namespace __format
428{
429 // pre: first != last
430 template<typename _CharT>
431 constexpr pair<unsigned short, const _CharT*>
432 __parse_integer(const _CharT* __first, const _CharT* __last)
433 {
434 if (__first == __last)
435 __builtin_unreachable();
436
437 if constexpr (is_same_v<_CharT, char>)
438 {
439 const auto __start = __first;
440 unsigned short __val = 0;
441 // N.B. std::from_chars is not constexpr in C++20.
442 if (__detail::__from_chars_alnum<true>(__first, __last, __val, 10)
443 && __first != __start) [[likely]]
444 return {__val, __first};
445 }
446 else
447 {
448 constexpr int __n = 32;
449 char __buf[__n]{};
450 for (int __i = 0; __i < __n && (__first + __i) != __last; ++__i)
451 __buf[__i] = __first[__i];
452 auto [__v, __ptr] = __format::__parse_integer(__buf, __buf + __n);
453 if (__ptr) [[likely]]
454 return {__v, __first + (__ptr - __buf)};
455 }
456 return {0, nullptr};
457 }
458
459 template<typename _CharT>
460 constexpr pair<unsigned short, const _CharT*>
461 __parse_arg_id(const _CharT* __first, const _CharT* __last)
462 {
463 if (__first == __last)
464 __builtin_unreachable();
465
466 if (*__first == '0')
467 return {0, __first + 1}; // No leading zeros allowed, so '0...' == 0
468
469 if ('1' <= *__first && *__first <= '9')
470 {
471 const unsigned short __id = *__first - '0';
472 const auto __next = __first + 1;
473 // Optimize for most likely case of single digit arg-id.
474 if (__next == __last || !('0' <= *__next && *__next <= '9'))
475 return {__id, __next};
476 else
477 return __format::__parse_integer(__first, __last);
478 }
479 return {0, nullptr};
480 }
481
482 enum _Pres_type {
483 _Pres_none = 0, // Default type (not valid for integer presentation types).
484 // Presentation types for integral types (including bool and charT).
485 _Pres_d = 1, _Pres_b, _Pres_B, _Pres_o, _Pres_x, _Pres_X, _Pres_c,
486 // Presentation types for floating-point types.
487 _Pres_a = 1, _Pres_A, _Pres_e, _Pres_E, _Pres_f, _Pres_F, _Pres_g, _Pres_G,
488 _Pres_p = 0, _Pres_P, // For pointers.
489 _Pres_s = 0, // For strings, bool
490 _Pres_seq = 0, _Pres_str, // For ranges
491 _Pres_esc = 0xf, // For strings, charT and ranges
492 };
493
494 enum _Align {
495 _Align_default,
496 _Align_left,
497 _Align_right,
498 _Align_centre,
499 };
500
501 enum _Sign {
502 _Sign_default,
503 _Sign_plus,
504 _Sign_minus, // XXX does this need to be distinct from _Sign_default?
505 _Sign_space,
506 };
507
508 enum _WidthPrec {
509 _WP_none, // No width/prec specified.
510 _WP_value, // Fixed width/prec specified.
511 _WP_from_arg // Use a formatting argument for width/prec.
512 };
513
514 template<typename _Context>
515 size_t
516 __int_from_arg(const basic_format_arg<_Context>& __arg);
517
518 constexpr bool __is_digit(char __c)
519 { return std::__detail::__from_chars_alnum_to_val(__c) < 10; }
520
521 constexpr bool __is_xdigit(char __c)
522 { return std::__detail::__from_chars_alnum_to_val(__c) < 16; }
523
524 template<typename _CharT>
525 struct _Spec
526 {
527 _Align _M_align : 2;
528 _Sign _M_sign : 2;
529 unsigned _M_alt : 1;
530 unsigned _M_localized : 1;
531 unsigned _M_zero_fill : 1;
532 _WidthPrec _M_width_kind : 2;
533 _WidthPrec _M_prec_kind : 2;
534 _Pres_type _M_type : 4;
535 unsigned _M_reserved : 1;
536 unsigned _M_reserved2 : 16;
537 unsigned short _M_width;
538 unsigned short _M_prec;
539 char32_t _M_fill = ' ';
540
541 using iterator = typename basic_string_view<_CharT>::iterator;
542
543 static constexpr _Align
544 _S_align(_CharT __c) noexcept
545 {
546 switch (__c)
547 {
548 case '<': return _Align_left;
549 case '>': return _Align_right;
550 case '^': return _Align_centre;
551 default: return _Align_default;
552 }
553 }
554
555 // pre: __first != __last
556 constexpr iterator
557 _M_parse_fill_and_align(iterator __first, iterator __last) noexcept
558 { return _M_parse_fill_and_align(__first, __last, "{"); }
559
560 // pre: __first != __last
561 constexpr iterator
562 _M_parse_fill_and_align(iterator __first, iterator __last, string_view __not_fill) noexcept
563 {
564 for (char __c : __not_fill)
565 if (*__first == static_cast<_CharT>(__c))
566 return __first;
567
568 using namespace __unicode;
569 if constexpr (__literal_encoding_is_unicode<_CharT>())
570 {
571 // Accept any UCS scalar value as fill character.
572 _Utf32_view<ranges::subrange<iterator>> __uv({__first, __last});
573 if (!__uv.empty())
574 {
575 auto __beg = __uv.begin();
576 char32_t __c = *__beg++;
577 if (__is_scalar_value(__c))
578 if (auto __next = __beg.base(); __next != __last)
579 if (_Align __align = _S_align(*__next))
580 {
581 _M_fill = __c;
582 _M_align = __align;
583 return ++__next;
584 }
585 }
586 }
587 else if (__last - __first >= 2)
588 if (_Align __align = _S_align(__first[1]))
589 {
590 _M_fill = *__first;
591 _M_align = __align;
592 return __first + 2;
593 }
594
595 if (_Align __align = _S_align(__first[0]))
596 {
597 _M_fill = ' ';
598 _M_align = __align;
599 return __first + 1;
600 }
601 return __first;
602 }
603
604 static constexpr _Sign
605 _S_sign(_CharT __c) noexcept
606 {
607 switch (__c)
608 {
609 case '+': return _Sign_plus;
610 case '-': return _Sign_minus;
611 case ' ': return _Sign_space;
612 default: return _Sign_default;
613 }
614 }
615
616 // pre: __first != __last
617 constexpr iterator
618 _M_parse_sign(iterator __first, iterator) noexcept
619 {
620 if (_Sign __sign = _S_sign(*__first))
621 {
622 _M_sign = __sign;
623 return __first + 1;
624 }
625 return __first;
626 }
627
628 // pre: *__first is valid
629 constexpr iterator
630 _M_parse_alternate_form(iterator __first, iterator) noexcept
631 {
632 if (*__first == '#')
633 {
634 _M_alt = true;
635 ++__first;
636 }
637 return __first;
638 }
639
640 // pre: __first != __last
641 constexpr iterator
642 _M_parse_zero_fill(iterator __first, iterator /* __last */) noexcept
643 {
644 if (*__first == '0')
645 {
646 _M_zero_fill = true;
647 ++__first;
648 }
649 return __first;
650 }
651
652 // pre: __first != __last
653 static constexpr iterator
654 _S_parse_width_or_precision(iterator __first, iterator __last,
655 unsigned short& __val, bool& __arg_id,
656 basic_format_parse_context<_CharT>& __pc)
657 {
658 if (__format::__is_digit(*__first))
659 {
660 auto [__v, __ptr] = __format::__parse_integer(__first, __last);
661 if (!__ptr)
662 __throw_format_error("format error: invalid width or precision "
663 "in format-spec");
664 __first = __ptr;
665 __val = __v;
666 }
667 else if (*__first == '{')
668 {
669 __arg_id = true;
670 ++__first;
671 if (__first == __last)
672 __format::__unmatched_left_brace_in_format_string();
673 if (*__first == '}')
674 __val = __pc.next_arg_id();
675 else
676 {
677 auto [__v, __ptr] = __format::__parse_arg_id(__first, __last);
678 if (__ptr == nullptr || __ptr == __last || *__ptr != '}')
679 __format::__invalid_arg_id_in_format_string();
680 __first = __ptr;
681 __pc.check_arg_id(__v);
682 __val = __v;
683 }
684#if __cpp_lib_format >= 202305L
685 __pc.check_dynamic_spec_integral(__val);
686#endif
687 ++__first; // past the '}'
688 }
689 return __first;
690 }
691
692 // pre: __first != __last
693 constexpr iterator
694 _M_parse_width(iterator __first, iterator __last,
695 basic_format_parse_context<_CharT>& __pc)
696 {
697 bool __arg_id = false;
698 if (*__first == '0')
699 __throw_format_error("format error: width must be non-zero in "
700 "format string");
701 auto __next = _S_parse_width_or_precision(__first, __last, _M_width,
702 __arg_id, __pc);
703 if (__next != __first)
704 _M_width_kind = __arg_id ? _WP_from_arg : _WP_value;
705 return __next;
706 }
707
708 // pre: __first != __last
709 constexpr iterator
710 _M_parse_precision(iterator __first, iterator __last,
711 basic_format_parse_context<_CharT>& __pc)
712 {
713 if (__first[0] != '.')
714 return __first;
715
716 iterator __next = ++__first;
717 bool __arg_id = false;
718 if (__next != __last)
719 __next = _S_parse_width_or_precision(__first, __last, _M_prec,
720 __arg_id, __pc);
721 if (__next == __first)
722 __throw_format_error("format error: missing precision after '.' in "
723 "format string");
724 _M_prec_kind = __arg_id ? _WP_from_arg : _WP_value;
725 return __next;
726 }
727
728 // pre: __first != __last
729 constexpr iterator
730 _M_parse_locale(iterator __first, iterator /* __last */) noexcept
731 {
732 if (*__first == 'L')
733 {
734 _M_localized = true;
735 ++__first;
736 }
737 return __first;
738 }
739
740 template<typename _Context>
741 size_t
742 _M_get_width(_Context& __ctx) const
743 {
744 size_t __width = 0;
745 if (_M_width_kind == _WP_value)
746 __width = _M_width;
747 else if (_M_width_kind == _WP_from_arg)
748 __width = __format::__int_from_arg(__ctx.arg(_M_width));
749 return __width;
750 }
751
752 template<typename _Context>
753 size_t
754 _M_get_precision(_Context& __ctx) const
755 {
756 size_t __prec = -1;
757 if (_M_prec_kind == _WP_value)
758 __prec = _M_prec;
759 else if (_M_prec_kind == _WP_from_arg)
760 __prec = __format::__int_from_arg(__ctx.arg(_M_prec));
761 return __prec;
762 }
763 };
764
765 template<typename _Int>
766 inline char*
767 __put_sign(_Int __i, _Sign __sign, char* __dest) noexcept
768 {
769 if (__i < 0)
770 *__dest = '-';
771 else if (__sign == _Sign_plus)
772 *__dest = '+';
773 else if (__sign == _Sign_space)
774 *__dest = ' ';
775 else
776 ++__dest;
777 return __dest;
778 }
779
780 // Write STR to OUT (and do so efficiently if OUT is a _Sink_iter).
781 template<typename _Out, typename _CharT>
782 requires output_iterator<_Out, const _CharT&>
783 inline _Out
784 __write(_Out __out, basic_string_view<_CharT> __str)
785 {
786 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
787 {
788 if (__str.size())
789 __out = __str;
790 }
791 else
792 for (_CharT __c : __str)
793 *__out++ = __c;
794 return __out;
795 }
796
797 // Write STR to OUT with NFILL copies of FILL_CHAR specified by ALIGN.
798 // pre: __align != _Align_default
799 template<typename _Out, typename _CharT>
800 _Out
801 __write_padded(_Out __out, basic_string_view<_CharT> __str,
802 _Align __align, size_t __nfill, char32_t __fill_char)
803 {
804 const size_t __buflen = 0x20;
805 _CharT __padding_chars[__buflen];
806 __padding_chars[0] = _CharT();
807 basic_string_view<_CharT> __padding{__padding_chars, __buflen};
808
809 auto __pad = [&__padding] (size_t __n, _Out& __o) {
810 if (__n == 0)
811 return;
812 while (__n > __padding.size())
813 {
814 __o = __format::__write(std::move(__o), __padding);
815 __n -= __padding.size();
816 }
817 if (__n != 0)
818 __o = __format::__write(std::move(__o), __padding.substr(0, __n));
819 };
820
821 size_t __l, __r, __max;
822 if (__align == _Align_centre)
823 {
824 __l = __nfill / 2;
825 __r = __l + (__nfill & 1);
826 __max = __r;
827 }
828 else if (__align == _Align_right)
829 {
830 __l = __nfill;
831 __r = 0;
832 __max = __l;
833 }
834 else
835 {
836 __l = 0;
837 __r = __nfill;
838 __max = __r;
839 }
840
841 using namespace __unicode;
842 if constexpr (__literal_encoding_is_unicode<_CharT>())
843 if (!__is_single_code_unit<_CharT>(__fill_char)) [[unlikely]]
844 {
845 // Encode fill char as multiple code units of type _CharT.
846 const char32_t __arr[1]{ __fill_char };
847 _Utf_view<_CharT, const char32_t(&)[1]> __v(__arr);
848 basic_string<_CharT> __padstr(__v.begin(), __v.end());
849 __padding = __padstr;
850 while (__l-- > 0)
851 __out = __format::__write(std::move(__out), __padding);
852 __out = __format::__write(std::move(__out), __str);
853 while (__r-- > 0)
854 __out = __format::__write(std::move(__out), __padding);
855 return __out;
856 }
857
858 if (__max < __buflen)
859 __padding.remove_suffix(__buflen - __max);
860 else
861 __max = __buflen;
862
863 char_traits<_CharT>::assign(__padding_chars, __max, __fill_char);
864 __pad(__l, __out);
865 __out = __format::__write(std::move(__out), __str);
866 __pad(__r, __out);
867
868 return __out;
869 }
870
871 // Write STR to OUT, with alignment and padding as determined by SPEC.
872 // pre: __spec._M_align != _Align_default || __align != _Align_default
873 template<typename _CharT, typename _Out>
874 _Out
875 __write_padded_as_spec(basic_string_view<type_identity_t<_CharT>> __str,
876 size_t __estimated_width,
877 basic_format_context<_Out, _CharT>& __fc,
878 const _Spec<_CharT>& __spec,
879 _Align __align = _Align_left)
880 {
881 size_t __width = __spec._M_get_width(__fc);
882
883 if (__width <= __estimated_width)
884 return __format::__write(__fc.out(), __str);
885
886 const size_t __nfill = __width - __estimated_width;
887
888 if (__spec._M_align)
889 __align = __spec._M_align;
890
891 return __format::__write_padded(__fc.out(), __str, __align, __nfill,
892 __spec._M_fill);
893 }
894
895 // Values are indices into _Escapes::all.
896 enum class _Term_char : unsigned char {
897 _Tc_quote = 12,
898 _Tc_apos = 15
899 };
900
901 template<typename _CharT>
902 struct _Escapes
903 {
904 using _Str_view = basic_string_view<_CharT>;
905
906 static consteval
907 _Str_view _S_all()
908 { return _GLIBCXX_WIDEN("\t\\t\n\\n\r\\r\\\\\\\"\\\"'\\'\\u\\x"); }
909
910 static constexpr
911 _CharT _S_term(_Term_char __term)
912 { return _S_all()[static_cast<unsigned char>(__term)]; }
913
914 static consteval
915 _Str_view _S_tab()
916 { return _S_all().substr(0, 3); }
917
918 static consteval
919 _Str_view _S_newline()
920 { return _S_all().substr(3, 3); }
921
922 static consteval
923 _Str_view _S_return()
924 { return _S_all().substr(6, 3); }
925
926 static consteval
927 _Str_view _S_bslash()
928 { return _S_all().substr(9, 3); }
929
930 static consteval
931 _Str_view _S_quote()
932 { return _S_all().substr(12, 3); }
933
934 static consteval
935 _Str_view _S_apos()
936 { return _S_all().substr(15, 3); }
937
938 static consteval
939 _Str_view _S_u()
940 { return _S_all().substr(18, 2); }
941
942 static consteval
943 _Str_view _S_x()
944 { return _S_all().substr(20, 2); }
945 };
946
947 template<typename _CharT>
948 struct _Separators
949 {
950 using _Str_view = basic_string_view<_CharT>;
951
952 static consteval
953 _Str_view _S_all()
954 { return _GLIBCXX_WIDEN("[]{}(), : "); }
955
956 static consteval
957 _Str_view _S_squares()
958 { return _S_all().substr(0, 2); }
959
960 static consteval
961 _Str_view _S_braces()
962 { return _S_all().substr(2, 2); }
963
964 static consteval
965 _Str_view _S_parens()
966 { return _S_all().substr(4, 2); }
967
968 static consteval
969 _Str_view _S_comma()
970 { return _S_all().substr(6, 2); }
971
972 static consteval
973 _Str_view _S_colon()
974 { return _S_all().substr(8, 2); }
975 };
976
977 template<typename _CharT>
978 constexpr bool __should_escape_ascii(_CharT __c, _Term_char __term)
979 {
980 using _Esc = _Escapes<_CharT>;
981 switch (__c)
982 {
983 case _Esc::_S_tab()[0]:
984 case _Esc::_S_newline()[0]:
985 case _Esc::_S_return()[0]:
986 case _Esc::_S_bslash()[0]:
987 return true;
988 case _Esc::_S_quote()[0]:
989 return __term == _Term_char::_Tc_quote;
990 case _Esc::_S_apos()[0]:
991 return __term == _Term_char::_Tc_apos;
992 default:
993 return (__c >= 0 && __c < 0x20) || __c == 0x7f;
994 };
995 }
996
997 // @pre __c <= 0x10FFFF
998 constexpr bool __should_escape_unicode(char32_t __c, bool __prev_esc)
999 {
1000 if (__unicode::__should_escape_category(__c))
1001 return __c != U' ';
1002 if (!__prev_esc)
1003 return false;
1004 return __unicode::__grapheme_cluster_break_property(__c)
1005 == __unicode::_Gcb_property::_Gcb_Extend;
1006 }
1007
1008 using uint_least32_t = __UINT_LEAST32_TYPE__;
1009 template<typename _Out, typename _CharT>
1010 _Out
1011 __write_escape_seq(_Out __out, uint_least32_t __val,
1012 basic_string_view<_CharT> __prefix)
1013 {
1014 using _Str_view = basic_string_view<_CharT>;
1015 constexpr size_t __max = 8;
1016 char __buf[__max];
1017 const string_view __narrow(
1018 __buf,
1019 std::__to_chars_i<uint_least32_t>(__buf, __buf + __max, __val, 16).ptr);
1020
1021 __out = __format::__write(__out, __prefix);
1022 *__out = _Separators<_CharT>::_S_braces()[0];
1023 ++__out;
1024 if constexpr (is_same_v<char, _CharT>)
1025 __out = __format::__write(__out, __narrow);
1026#ifdef _GLIBCXX_USE_WCHAR_T
1027 else
1028 {
1029 _CharT __wbuf[__max];
1030 const size_t __n = __narrow.size();
1031 std::__to_wstring_numeric(__narrow.data(), __n, __wbuf);
1032 __out = __format::__write(__out, _Str_view(__wbuf, __n));
1033 }
1034#endif
1035 *__out = _Separators<_CharT>::_S_braces()[1];
1036 return ++__out;
1037 }
1038
1039 template<typename _Out, typename _CharT>
1040 _Out
1041 __write_escaped_char(_Out __out, _CharT __c)
1042 {
1043 using _UChar = make_unsigned_t<_CharT>;
1044 using _Esc = _Escapes<_CharT>;
1045 switch (__c)
1046 {
1047 case _Esc::_S_tab()[0]:
1048 return __format::__write(__out, _Esc::_S_tab().substr(1, 2));
1049 case _Esc::_S_newline()[0]:
1050 return __format::__write(__out, _Esc::_S_newline().substr(1, 2));
1051 case _Esc::_S_return()[0]:
1052 return __format::__write(__out, _Esc::_S_return().substr(1, 2));
1053 case _Esc::_S_bslash()[0]:
1054 return __format::__write(__out, _Esc::_S_bslash().substr(1, 2));
1055 case _Esc::_S_quote()[0]:
1056 return __format::__write(__out, _Esc::_S_quote().substr(1, 2));
1057 case _Esc::_S_apos()[0]:
1058 return __format::__write(__out, _Esc::_S_apos().substr(1, 2));
1059 default:
1060 return __format::__write_escape_seq(__out,
1061 static_cast<_UChar>(__c),
1062 _Esc::_S_u());
1063 }
1064 }
1065
1066 template<typename _CharT, typename _Out>
1067 _Out
1068 __write_escaped_ascii(_Out __out,
1069 basic_string_view<_CharT> __str,
1070 _Term_char __term)
1071 {
1072 using _Str_view = basic_string_view<_CharT>;
1073 auto __first = __str.begin();
1074 auto const __last = __str.end();
1075 while (__first != __last)
1076 {
1077 auto __print = __first;
1078 // assume anything outside ASCII is printable
1079 while (__print != __last
1080 && !__format::__should_escape_ascii(*__print, __term))
1081 ++__print;
1082
1083 if (__print != __first)
1084 __out = __format::__write(__out, _Str_view(__first, __print));
1085
1086 if (__print == __last)
1087 return __out;
1088
1089 __first = __print;
1090 __out = __format::__write_escaped_char(__out, *__first);
1091 ++__first;
1092 }
1093 return __out;
1094 }
1095
1096 template<typename _CharT, typename _Out>
1097 _Out
1098 __write_escaped_unicode(_Out __out,
1099 basic_string_view<_CharT> __str,
1100 _Term_char __term)
1101 {
1102 using _Str_view = basic_string_view<_CharT>;
1103 using _UChar = make_unsigned_t<_CharT>;
1104 using _Esc = _Escapes<_CharT>;
1105
1106 static constexpr char32_t __replace = U'\uFFFD';
1107 static constexpr _Str_view __replace_rep = []
1108 {
1109 // N.B. "\uFFFD" is ill-formed if encoding is not unicode.
1110 if constexpr (is_same_v<char, _CharT>)
1111 return "\xEF\xBF\xBD";
1112 else
1113 return L"\xFFFD";
1114 }();
1115
1116 __unicode::_Utf_view<char32_t, _Str_view> __v(std::move(__str));
1117 auto __first = __v.begin();
1118 auto const __last = __v.end();
1119
1120 bool __prev_esc = true;
1121 while (__first != __last)
1122 {
1123 bool __esc_ascii = false;
1124 bool __esc_unicode = false;
1125 bool __esc_replace = false;
1126 auto __should_escape = [&](auto const& __it)
1127 {
1128 if (*__it <= 0x7f)
1129 return __esc_ascii
1130 = __format::__should_escape_ascii(*__it.base(), __term);
1131 if (__format::__should_escape_unicode(*__it, __prev_esc))
1132 return __esc_unicode = true;
1133 if (*__it == __replace)
1134 {
1135 _Str_view __units(__it.base(), __it._M_units());
1136 return __esc_replace = (__units != __replace_rep);
1137 }
1138 return false;
1139 };
1140
1141 auto __print = __first;
1142 while (__print != __last && !__should_escape(__print))
1143 {
1144 __prev_esc = false;
1145 ++__print;
1146 }
1147
1148 if (__print != __first)
1149 __out = __format::__write(__out, _Str_view(__first.base(), __print.base()));
1150
1151 if (__print == __last)
1152 return __out;
1153
1154 __first = __print;
1155 if (__esc_ascii)
1156 __out = __format::__write_escaped_char(__out, *__first.base());
1157 else if (__esc_unicode)
1158 __out = __format::__write_escape_seq(__out, *__first, _Esc::_S_u());
1159 else // __esc_replace
1160 for (_CharT __c : _Str_view(__first.base(), __first._M_units()))
1161 __out = __format::__write_escape_seq(__out,
1162 static_cast<_UChar>(__c),
1163 _Esc::_S_x());
1164 __prev_esc = true;
1165 ++__first;
1166
1167 }
1168 return __out;
1169 }
1170
1171 template<typename _CharT, typename _Out>
1172 _Out
1173 __write_escaped(_Out __out, basic_string_view<_CharT> __str, _Term_char __term)
1174 {
1175 *__out = _Escapes<_CharT>::_S_term(__term);
1176 ++__out;
1177
1178 if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
1179 __out = __format::__write_escaped_unicode(__out, __str, __term);
1180 else if constexpr (is_same_v<char, _CharT>
1181 && __unicode::__literal_encoding_is_extended_ascii())
1182 __out = __format::__write_escaped_ascii(__out, __str, __term);
1183 else
1184 // TODO Handle non-ascii extended encoding
1185 __out = __format::__write_escaped_ascii(__out, __str, __term);
1186
1187 *__out = _Escapes<_CharT>::_S_term(__term);
1188 return ++__out;
1189 }
1190
1191 // A lightweight optional<locale>.
1192 struct _Optional_locale
1193 {
1194 [[__gnu__::__always_inline__]]
1195 _Optional_locale() : _M_dummy(), _M_hasval(false) { }
1196
1197 _Optional_locale(const locale& __loc) noexcept
1198 : _M_loc(__loc), _M_hasval(true)
1199 { }
1200
1201 _Optional_locale(const _Optional_locale& __l) noexcept
1202 : _M_dummy(), _M_hasval(__l._M_hasval)
1203 {
1204 if (_M_hasval)
1205 std::construct_at(&_M_loc, __l._M_loc);
1206 }
1207
1208 _Optional_locale&
1209 operator=(const _Optional_locale& __l) noexcept
1210 {
1211 if (_M_hasval)
1212 {
1213 if (__l._M_hasval)
1214 _M_loc = __l._M_loc;
1215 else
1216 {
1217 _M_loc.~locale();
1218 _M_hasval = false;
1219 }
1220 }
1221 else if (__l._M_hasval)
1222 {
1223 std::construct_at(&_M_loc, __l._M_loc);
1224 _M_hasval = true;
1225 }
1226 return *this;
1227 }
1228
1229 ~_Optional_locale() { if (_M_hasval) _M_loc.~locale(); }
1230
1231 _Optional_locale&
1232 operator=(locale&& __loc) noexcept
1233 {
1234 if (_M_hasval)
1235 _M_loc = std::move(__loc);
1236 else
1237 {
1238 std::construct_at(&_M_loc, std::move(__loc));
1239 _M_hasval = true;
1240 }
1241 return *this;
1242 }
1243
1244 const locale&
1245 value() noexcept
1246 {
1247 if (!_M_hasval)
1248 {
1249 std::construct_at(&_M_loc);
1250 _M_hasval = true;
1251 }
1252 return _M_loc;
1253 }
1254
1255 bool has_value() const noexcept { return _M_hasval; }
1256
1257 union {
1258 char _M_dummy = '\0';
1259 std::locale _M_loc;
1260 };
1261 bool _M_hasval = false;
1262 };
1263
1264 template<__char _CharT>
1265 struct __formatter_str
1266 {
1267 __formatter_str() = default;
1268
1269 constexpr
1270 __formatter_str(_Spec<_CharT> __spec) noexcept
1271 : _M_spec(__spec)
1272 { }
1273
1274 constexpr typename basic_format_parse_context<_CharT>::iterator
1275 parse(basic_format_parse_context<_CharT>& __pc)
1276 {
1277 auto __first = __pc.begin();
1278 const auto __last = __pc.end();
1279 _Spec<_CharT> __spec{};
1280
1281 auto __finalize = [this, &__spec] {
1282 _M_spec = __spec;
1283 };
1284
1285 auto __finished = [&] {
1286 if (__first == __last || *__first == '}')
1287 {
1288 __finalize();
1289 return true;
1290 }
1291 return false;
1292 };
1293
1294 if (__finished())
1295 return __first;
1296
1297 __first = __spec._M_parse_fill_and_align(__first, __last);
1298 if (__finished())
1299 return __first;
1300
1301 __first = __spec._M_parse_width(__first, __last, __pc);
1302 if (__finished())
1303 return __first;
1304
1305 __first = __spec._M_parse_precision(__first, __last, __pc);
1306 if (__finished())
1307 return __first;
1308
1309 if (*__first == 's')
1310 ++__first;
1311#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
1312 else if (*__first == '?')
1313 {
1314 __spec._M_type = _Pres_esc;
1315 ++__first;
1316 }
1317#endif
1318
1319 if (__finished())
1320 return __first;
1321
1322 __format::__failed_to_parse_format_spec();
1323 }
1324
1325 template<typename _Out>
1326 _Out
1327 format(basic_string_view<_CharT> __s,
1328 basic_format_context<_Out, _CharT>& __fc) const
1329 {
1330 constexpr auto __term = __format::_Term_char::_Tc_quote;
1331 const auto __write_direct = [&]
1332 {
1333 if (_M_spec._M_type == _Pres_esc)
1334 return __format::__write_escaped(__fc.out(), __s, __term);
1335 else
1336 return __format::__write(__fc.out(), __s);
1337 };
1338
1339 if (_M_spec._M_width_kind == _WP_none
1340 && _M_spec._M_prec_kind == _WP_none)
1341 return __write_direct();
1342
1343 const size_t __prec =
1344 _M_spec._M_prec_kind != _WP_none
1345 ? _M_spec._M_get_precision(__fc)
1346 : basic_string_view<_CharT>::npos;
1347
1348 const size_t __estimated_width = _S_trunc(__s, __prec);
1349 // N.B. Escaping only increases width
1350 if (_M_spec._M_get_width(__fc) <= __estimated_width
1351 && _M_spec._M_prec_kind == _WP_none)
1352 return __write_direct();
1353
1354 if (_M_spec._M_type != _Pres_esc)
1355 return __format::__write_padded_as_spec(__s, __estimated_width,
1356 __fc, _M_spec);
1357
1358 __format::_Str_sink<_CharT> __sink;
1359 __format::__write_escaped(__sink.out(), __s, __term);
1360 basic_string_view<_CharT> __escaped(__sink.view().data(),
1361 __sink.view().size());
1362 const size_t __escaped_width = _S_trunc(__escaped, __prec);
1363 // N.B. [tab:format.type.string] defines '?' as
1364 // Copies the escaped string ([format.string.escaped]) to the output,
1365 // so precision seem to appy to escaped string.
1366 return __format::__write_padded_as_spec(__escaped, __escaped_width,
1367 __fc, _M_spec);
1368 }
1369
1370#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
1371 template<ranges::input_range _Rg, typename _Out>
1372 requires same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>, _CharT>
1373 typename basic_format_context<_Out, _CharT>::iterator
1374 _M_format_range(_Rg&& __rg, basic_format_context<_Out, _CharT>& __fc) const
1375 {
1376 using _String = basic_string<_CharT>;
1377 using _String_view = basic_string_view<_CharT>;
1378 if constexpr (ranges::forward_range<_Rg> || ranges::sized_range<_Rg>)
1379 {
1380 const size_t __n(ranges::distance(__rg));
1381 if constexpr (ranges::contiguous_range<_Rg>)
1382 return format(_String_view(ranges::data(__rg), __n), __fc);
1383 else if (__n <= __format::__stackbuf_size<_CharT>)
1384 {
1385 _CharT __buf[__format::__stackbuf_size<_CharT>];
1386 ranges::copy(__rg, __buf);
1387 return format(_String_view(__buf, __n), __fc);
1388 }
1389 else if constexpr (ranges::sized_range<_Rg>)
1390 return format(_String(from_range, __rg), __fc);
1391 else if constexpr (ranges::random_access_range<_Rg>)
1392 {
1393 ranges::iterator_t<_Rg> __first = ranges::begin(__rg);
1394 ranges::subrange __sub(__first, __first + __n);
1395 return format(_String(from_range, __sub), __fc);
1396 }
1397 else
1398 {
1399 // N.B. preserve the computed size
1400 ranges::subrange __sub(__rg, __n);
1401 return format(_String(from_range, __sub), __fc);
1402 }
1403 }
1404 else
1405 return format(_String(from_range, __rg), __fc);
1406 }
1407
1408 constexpr void
1409 set_debug_format() noexcept
1410 { _M_spec._M_type = _Pres_esc; }
1411#endif
1412
1413 private:
1414 static size_t
1415 _S_trunc(basic_string_view<_CharT>& __s, size_t __prec)
1416 {
1417 if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
1418 {
1419 if (__prec != basic_string_view<_CharT>::npos)
1420 return __unicode::__truncate(__s, __prec);
1421 else
1422 return __unicode::__field_width(__s);
1423 }
1424 else
1425 {
1426 __s = __s.substr(0, __prec);
1427 return __s.size();
1428 }
1429 }
1430
1431 _Spec<_CharT> _M_spec{};
1432 };
1433
1434 template<__char _CharT>
1435 struct __formatter_int
1436 {
1437 // If no presentation type is specified, meaning of "none" depends
1438 // whether we are formatting an integer or a char or a bool.
1439 static constexpr _Pres_type _AsInteger = _Pres_d;
1440 static constexpr _Pres_type _AsBool = _Pres_s;
1441 static constexpr _Pres_type _AsChar = _Pres_c;
1442
1443 constexpr typename basic_format_parse_context<_CharT>::iterator
1444 _M_do_parse(basic_format_parse_context<_CharT>& __pc, _Pres_type __type)
1445 {
1446 _Spec<_CharT> __spec{};
1447 __spec._M_type = __type;
1448
1449 const auto __last = __pc.end();
1450 auto __first = __pc.begin();
1451
1452 auto __finalize = [this, &__spec] {
1453 _M_spec = __spec;
1454 };
1455
1456 auto __finished = [&] {
1457 if (__first == __last || *__first == '}')
1458 {
1459 __finalize();
1460 return true;
1461 }
1462 return false;
1463 };
1464
1465 if (__finished())
1466 return __first;
1467
1468 __first = __spec._M_parse_fill_and_align(__first, __last);
1469 if (__finished())
1470 return __first;
1471
1472 __first = __spec._M_parse_sign(__first, __last);
1473 if (__finished())
1474 return __first;
1475
1476 __first = __spec._M_parse_alternate_form(__first, __last);
1477 if (__finished())
1478 return __first;
1479
1480 __first = __spec._M_parse_zero_fill(__first, __last);
1481 if (__finished())
1482 return __first;
1483
1484 __first = __spec._M_parse_width(__first, __last, __pc);
1485 if (__finished())
1486 return __first;
1487
1488 __first = __spec._M_parse_locale(__first, __last);
1489 if (__finished())
1490 return __first;
1491
1492 switch (*__first)
1493 {
1494 case 'b':
1495 __spec._M_type = _Pres_b;
1496 ++__first;
1497 break;
1498 case 'B':
1499 __spec._M_type = _Pres_B;
1500 ++__first;
1501 break;
1502 case 'c':
1503 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1504 // 3586. format should not print bool with 'c'
1505 if (__type != _AsBool)
1506 {
1507 __spec._M_type = _Pres_c;
1508 ++__first;
1509 }
1510 break;
1511 case 'd':
1512 __spec._M_type = _Pres_d;
1513 ++__first;
1514 break;
1515 case 'o':
1516 __spec._M_type = _Pres_o;
1517 ++__first;
1518 break;
1519 case 'x':
1520 __spec._M_type = _Pres_x;
1521 ++__first;
1522 break;
1523 case 'X':
1524 __spec._M_type = _Pres_X;
1525 ++__first;
1526 break;
1527 case 's':
1528 if (__type == _AsBool)
1529 {
1530 __spec._M_type = _Pres_s; // same value (and meaning) as "none"
1531 ++__first;
1532 }
1533 break;
1534#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
1535 case '?':
1536 if (__type == _AsChar)
1537 {
1538 __spec._M_type = _Pres_esc;
1539 ++__first;
1540 }
1541#endif
1542 break;
1543 }
1544
1545 if (__finished())
1546 return __first;
1547
1548 __format::__failed_to_parse_format_spec();
1549 }
1550
1551 template<typename _Tp>
1552 constexpr typename basic_format_parse_context<_CharT>::iterator
1553 _M_parse(basic_format_parse_context<_CharT>& __pc)
1554 {
1555 if constexpr (is_same_v<_Tp, bool>)
1556 {
1557 auto __end = _M_do_parse(__pc, _AsBool);
1558 if (_M_spec._M_type == _Pres_s)
1559 if (_M_spec._M_sign || _M_spec._M_alt || _M_spec._M_zero_fill)
1560 __throw_format_error("format error: format-spec contains "
1561 "invalid formatting options for "
1562 "'bool'");
1563 return __end;
1564 }
1565 else if constexpr (__char<_Tp>)
1566 {
1567 auto __end = _M_do_parse(__pc, _AsChar);
1568 if (_M_spec._M_type == _Pres_c || _M_spec._M_type == _Pres_esc)
1569 if (_M_spec._M_sign || _M_spec._M_alt || _M_spec._M_zero_fill
1570 /* XXX should be invalid? || _M_spec._M_localized */)
1571 __throw_format_error("format error: format-spec contains "
1572 "invalid formatting options for "
1573 "'charT'");
1574 return __end;
1575 }
1576 else
1577 return _M_do_parse(__pc, _AsInteger);
1578 }
1579
1580 template<typename _Int, typename _Out>
1581 typename basic_format_context<_Out, _CharT>::iterator
1582 format(_Int __i, basic_format_context<_Out, _CharT>& __fc) const
1583 {
1584 if (_M_spec._M_type == _Pres_c)
1585 return _M_format_character(_S_to_character(__i), __fc);
1586
1587 char __buf[sizeof(_Int) * __CHAR_BIT__ + 3];
1588 to_chars_result __res{};
1589
1590 string_view __base_prefix;
1591 make_unsigned_t<_Int> __u;
1592 if (__i < 0)
1593 __u = -static_cast<make_unsigned_t<_Int>>(__i);
1594 else
1595 __u = __i;
1596
1597 char* __start = __buf + 3;
1598 char* const __end = __buf + sizeof(__buf);
1599 char* const __start_digits = __start;
1600
1601 switch (_M_spec._M_type)
1602 {
1603 case _Pres_b:
1604 case _Pres_B:
1605 __base_prefix = _M_spec._M_type == _Pres_b ? "0b" : "0B";
1606 __res = to_chars(__start, __end, __u, 2);
1607 break;
1608#if 0
1609 case _Pres_c:
1610 return _M_format_character(_S_to_character(__i), __fc);
1611#endif
1612 case _Pres_none:
1613 // Should not reach here with _Pres_none for bool or charT, so:
1614 [[fallthrough]];
1615 case _Pres_d:
1616 __res = to_chars(__start, __end, __u, 10);
1617 break;
1618 case _Pres_o:
1619 if (__i != 0)
1620 __base_prefix = "0";
1621 __res = to_chars(__start, __end, __u, 8);
1622 break;
1623 case _Pres_x:
1624 case _Pres_X:
1625 __base_prefix = _M_spec._M_type == _Pres_x ? "0x" : "0X";
1626 __res = to_chars(__start, __end, __u, 16);
1627 if (_M_spec._M_type == _Pres_X)
1628 for (auto __p = __start; __p != __res.ptr; ++__p)
1629#if __has_builtin(__builtin_toupper)
1630 *__p = __builtin_toupper(*__p);
1631#else
1632 *__p = std::toupper(*__p);
1633#endif
1634 break;
1635 default:
1636 __builtin_unreachable();
1637 }
1638
1639 if (_M_spec._M_alt && __base_prefix.size())
1640 {
1641 __start -= __base_prefix.size();
1642 __builtin_memcpy(__start, __base_prefix.data(),
1643 __base_prefix.size());
1644 }
1645 __start = __format::__put_sign(__i, _M_spec._M_sign, __start - 1);
1646
1647 return _M_format_int(string_view(__start, __res.ptr - __start),
1648 __start_digits - __start, __fc);
1649 }
1650
1651 template<typename _Out>
1652 typename basic_format_context<_Out, _CharT>::iterator
1653 format(bool __i, basic_format_context<_Out, _CharT>& __fc) const
1654 {
1655 if (_M_spec._M_type == _Pres_c)
1656 return _M_format_character(static_cast<unsigned char>(__i), __fc);
1657 if (_M_spec._M_type != _Pres_s)
1658 return format(static_cast<unsigned char>(__i), __fc);
1659
1660 basic_string<_CharT> __s;
1661 size_t __est_width;
1662 if (_M_spec._M_localized) [[unlikely]]
1663 {
1664 auto& __np = std::use_facet<numpunct<_CharT>>(__fc.locale());
1665 __s = __i ? __np.truename() : __np.falsename();
1666 __est_width = __s.size(); // TODO Unicode-aware estimate
1667 }
1668 else
1669 {
1670 if constexpr (is_same_v<char, _CharT>)
1671 __s = __i ? "true" : "false";
1672 else
1673 __s = __i ? L"true" : L"false";
1674 __est_width = __s.size();
1675 }
1676
1677 return __format::__write_padded_as_spec(__s, __est_width, __fc,
1678 _M_spec);
1679 }
1680
1681 [[__gnu__::__always_inline__]]
1682 static size_t
1683 _S_character_width(_CharT __c)
1684 {
1685 // N.B. single byte cannot encode charcter of width greater than 1
1686 if constexpr (sizeof(_CharT) > 1u &&
1687 __unicode::__literal_encoding_is_unicode<_CharT>())
1688 return __unicode::__field_width(__c);
1689 else
1690 return 1u;
1691 }
1692
1693 template<typename _Out>
1694 typename basic_format_context<_Out, _CharT>::iterator
1695 _M_format_character(_CharT __c,
1696 basic_format_context<_Out, _CharT>& __fc) const
1697 {
1698 return __format::__write_padded_as_spec({&__c, 1u},
1699 _S_character_width(__c),
1700 __fc, _M_spec);
1701 }
1702
1703 template<typename _Out>
1704 typename basic_format_context<_Out, _CharT>::iterator
1705 _M_format_character_escaped(_CharT __c,
1706 basic_format_context<_Out, _CharT>& __fc) const
1707 {
1708 using _Esc = _Escapes<_CharT>;
1709 constexpr auto __term = __format::_Term_char::_Tc_apos;
1710 const basic_string_view<_CharT> __in(&__c, 1u);
1711 if (_M_spec._M_get_width(__fc) <= 3u)
1712 return __format::__write_escaped(__fc.out(), __in, __term);
1713
1714 _CharT __buf[12];
1715 __format::_Fixedbuf_sink<_CharT> __sink(__buf);
1716 __format::__write_escaped(__sink.out(), __in, __term);
1717
1718 const basic_string_view<_CharT> __escaped = __sink.view();
1719 size_t __estimated_width;
1720 if (__escaped[1] == _Esc::_S_bslash()[0]) // escape sequence
1721 __estimated_width = __escaped.size();
1722 else
1723 __estimated_width = 2 + _S_character_width(__c);
1724 return __format::__write_padded_as_spec(__escaped,
1725 __estimated_width,
1726 __fc, _M_spec);
1727 }
1728
1729 template<typename _Int>
1730 static _CharT
1731 _S_to_character(_Int __i)
1732 {
1733 using _Traits = __gnu_cxx::__int_traits<_CharT>;
1734 if constexpr (is_signed_v<_Int> == is_signed_v<_CharT>)
1735 {
1736 if (_Traits::__min <= __i && __i <= _Traits::__max)
1737 return static_cast<_CharT>(__i);
1738 }
1739 else if constexpr (is_signed_v<_Int>)
1740 {
1741 if (__i >= 0 && make_unsigned_t<_Int>(__i) <= _Traits::__max)
1742 return static_cast<_CharT>(__i);
1743 }
1744 else if (__i <= make_unsigned_t<_CharT>(_Traits::__max))
1745 return static_cast<_CharT>(__i);
1746 __throw_format_error("format error: integer not representable as "
1747 "character");
1748 }
1749
1750 template<typename _Out>
1751 typename basic_format_context<_Out, _CharT>::iterator
1752 _M_format_int(string_view __narrow_str, size_t __prefix_len,
1753 basic_format_context<_Out, _CharT>& __fc) const
1754 {
1755 size_t __width = _M_spec._M_get_width(__fc);
1756
1757 basic_string_view<_CharT> __str;
1758 if constexpr (is_same_v<char, _CharT>)
1759 __str = __narrow_str;
1760#ifdef _GLIBCXX_USE_WCHAR_T
1761 else
1762 {
1763 size_t __n = __narrow_str.size();
1764 auto __p = (_CharT*)__builtin_alloca(__n * sizeof(_CharT));
1765 std::__to_wstring_numeric(__narrow_str.data(), __n, __p);
1766 __str = {__p, __n};
1767 }
1768#endif
1769
1770 if (_M_spec._M_localized)
1771 {
1772 const auto& __l = __fc.locale();
1773 if (__l.name() != "C")
1774 {
1775 auto& __np = use_facet<numpunct<_CharT>>(__l);
1776 string __grp = __np.grouping();
1777 if (!__grp.empty())
1778 {
1779 size_t __n = __str.size() - __prefix_len;
1780 auto __p = (_CharT*)__builtin_alloca(2 * __n
1781 * sizeof(_CharT)
1782 + __prefix_len);
1783 auto __s = __str.data();
1784 char_traits<_CharT>::copy(__p, __s, __prefix_len);
1785 __s += __prefix_len;
1786 auto __end = std::__add_grouping(__p + __prefix_len,
1787 __np.thousands_sep(),
1788 __grp.data(),
1789 __grp.size(),
1790 __s, __s + __n);
1791 __str = {__p, size_t(__end - __p)};
1792 }
1793 }
1794 }
1795
1796 if (__width <= __str.size())
1797 return __format::__write(__fc.out(), __str);
1798
1799 char32_t __fill_char = _M_spec._M_fill;
1800 _Align __align = _M_spec._M_align;
1801
1802 size_t __nfill = __width - __str.size();
1803 auto __out = __fc.out();
1804 if (__align == _Align_default)
1805 {
1806 __align = _Align_right;
1807 if (_M_spec._M_zero_fill)
1808 {
1809 __fill_char = _CharT('0');
1810 // Write sign and base prefix before zero filling.
1811 if (__prefix_len != 0)
1812 {
1813 __out = __format::__write(std::move(__out),
1814 __str.substr(0, __prefix_len));
1815 __str.remove_prefix(__prefix_len);
1816 }
1817 }
1818 else
1819 __fill_char = _CharT(' ');
1820 }
1821 return __format::__write_padded(std::move(__out), __str,
1822 __align, __nfill, __fill_char);
1823 }
1824
1825#if defined __SIZEOF_INT128__ && defined __STRICT_ANSI__
1826 template<typename _Tp>
1827 using make_unsigned_t
1828 = typename __conditional_t<(sizeof(_Tp) <= sizeof(long long)),
1829 std::make_unsigned<_Tp>,
1830 type_identity<unsigned __int128>>::type;
1831
1832 // std::to_chars is not overloaded for int128 in strict mode.
1833 template<typename _Int>
1834 static to_chars_result
1835 to_chars(char* __first, char* __last, _Int __value, int __base)
1836 { return std::__to_chars_i<_Int>(__first, __last, __value, __base); }
1837#endif
1838
1839 _Spec<_CharT> _M_spec{};
1840 };
1841
1842 // Decide how 128-bit floating-point types should be formatted (or not).
1843 // When supported, the typedef __format::__float128_t is the type that
1844 // format arguments should be converted to for storage in basic_format_arg.
1845 // Define the macro _GLIBCXX_FORMAT_F128 to say they're supported.
1846 // _GLIBCXX_FORMAT_F128=1 means __float128, _Float128 etc. will be formatted
1847 // by converting them to long double (or __ieee128 for powerpc64le).
1848 // _GLIBCXX_FORMAT_F128=2 means basic_format_arg needs to enable explicit
1849 // support for _Float128, rather than formatting it as another type.
1850#undef _GLIBCXX_FORMAT_F128
1851
1852#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
1853
1854 // Format 128-bit floating-point types using __ieee128.
1855 using __float128_t = __ieee128;
1856# define _GLIBCXX_FORMAT_F128 1
1857
1858#ifdef __LONG_DOUBLE_IEEE128__
1859 // These overloads exist in the library, but are not declared.
1860 // Make them available as std::__format::to_chars.
1861 to_chars_result
1862 to_chars(char*, char*, __ibm128) noexcept
1863 __asm("_ZSt8to_charsPcS_e");
1864
1865 to_chars_result
1866 to_chars(char*, char*, __ibm128, chars_format) noexcept
1867 __asm("_ZSt8to_charsPcS_eSt12chars_format");
1868
1869 to_chars_result
1870 to_chars(char*, char*, __ibm128, chars_format, int) noexcept
1871 __asm("_ZSt8to_charsPcS_eSt12chars_formati");
1872#elif __cplusplus == 202002L
1873 to_chars_result
1874 to_chars(char*, char*, __ieee128) noexcept
1875 __asm("_ZSt8to_charsPcS_u9__ieee128");
1876
1877 to_chars_result
1878 to_chars(char*, char*, __ieee128, chars_format) noexcept
1879 __asm("_ZSt8to_charsPcS_u9__ieee128St12chars_format");
1880
1881 to_chars_result
1882 to_chars(char*, char*, __ieee128, chars_format, int) noexcept
1883 __asm("_ZSt8to_charsPcS_u9__ieee128St12chars_formati");
1884#endif
1885
1886#elif defined _GLIBCXX_LDOUBLE_IS_IEEE_BINARY128
1887
1888 // Format 128-bit floating-point types using long double.
1889 using __float128_t = long double;
1890# define _GLIBCXX_FORMAT_F128 1
1891
1892#elif __FLT128_DIG__ && defined(_GLIBCXX_HAVE_FLOAT128_MATH)
1893
1894 // Format 128-bit floating-point types using _Float128.
1895 using __float128_t = _Float128;
1896# define _GLIBCXX_FORMAT_F128 2
1897
1898# if __cplusplus == 202002L
1899 // These overloads exist in the library, but are not declared for C++20.
1900 // Make them available as std::__format::to_chars.
1901 to_chars_result
1902 to_chars(char*, char*, _Float128) noexcept
1903# if _GLIBCXX_INLINE_VERSION
1904 __asm("_ZNSt3__88to_charsEPcS0_DF128_");
1905# else
1906 __asm("_ZSt8to_charsPcS_DF128_");
1907# endif
1908
1909 to_chars_result
1910 to_chars(char*, char*, _Float128, chars_format) noexcept
1911# if _GLIBCXX_INLINE_VERSION
1912 __asm("_ZNSt3__88to_charsEPcS0_DF128_NS_12chars_formatE");
1913# else
1914 __asm("_ZSt8to_charsPcS_DF128_St12chars_format");
1915# endif
1916
1917 to_chars_result
1918 to_chars(char*, char*, _Float128, chars_format, int) noexcept
1919# if _GLIBCXX_INLINE_VERSION
1920 __asm("_ZNSt3__88to_charsEPcS0_DF128_NS_12chars_formatEi");
1921# else
1922 __asm("_ZSt8to_charsPcS_DF128_St12chars_formati");
1923# endif
1924# endif
1925#endif
1926
1927 using std::to_chars;
1928
1929 // We can format a floating-point type iff it is usable with to_chars.
1930 template<typename _Tp>
1931 concept __formattable_float
1932 = is_same_v<remove_cv_t<_Tp>, _Tp> && requires (_Tp __t, char* __p)
1933 { __format::to_chars(__p, __p, __t, chars_format::scientific, 6); };
1934
1935 template<__char _CharT>
1936 struct __formatter_fp
1937 {
1938 constexpr typename basic_format_parse_context<_CharT>::iterator
1939 parse(basic_format_parse_context<_CharT>& __pc)
1940 {
1941 _Spec<_CharT> __spec{};
1942 const auto __last = __pc.end();
1943 auto __first = __pc.begin();
1944
1945 auto __finalize = [this, &__spec] {
1946 _M_spec = __spec;
1947 };
1948
1949 auto __finished = [&] {
1950 if (__first == __last || *__first == '}')
1951 {
1952 __finalize();
1953 return true;
1954 }
1955 return false;
1956 };
1957
1958 if (__finished())
1959 return __first;
1960
1961 __first = __spec._M_parse_fill_and_align(__first, __last);
1962 if (__finished())
1963 return __first;
1964
1965 __first = __spec._M_parse_sign(__first, __last);
1966 if (__finished())
1967 return __first;
1968
1969 __first = __spec._M_parse_alternate_form(__first, __last);
1970 if (__finished())
1971 return __first;
1972
1973 __first = __spec._M_parse_zero_fill(__first, __last);
1974 if (__finished())
1975 return __first;
1976
1977 if (__first[0] != '.')
1978 {
1979 __first = __spec._M_parse_width(__first, __last, __pc);
1980 if (__finished())
1981 return __first;
1982 }
1983
1984 __first = __spec._M_parse_precision(__first, __last, __pc);
1985 if (__finished())
1986 return __first;
1987
1988 __first = __spec._M_parse_locale(__first, __last);
1989 if (__finished())
1990 return __first;
1991
1992 switch (*__first)
1993 {
1994 case 'a':
1995 __spec._M_type = _Pres_a;
1996 ++__first;
1997 break;
1998 case 'A':
1999 __spec._M_type = _Pres_A;
2000 ++__first;
2001 break;
2002 case 'e':
2003 __spec._M_type = _Pres_e;
2004 ++__first;
2005 break;
2006 case 'E':
2007 __spec._M_type = _Pres_E;
2008 ++__first;
2009 break;
2010 case 'f':
2011 __spec._M_type = _Pres_f;
2012 ++__first;
2013 break;
2014 case 'F':
2015 __spec._M_type = _Pres_F;
2016 ++__first;
2017 break;
2018 case 'g':
2019 __spec._M_type = _Pres_g;
2020 ++__first;
2021 break;
2022 case 'G':
2023 __spec._M_type = _Pres_G;
2024 ++__first;
2025 break;
2026 }
2027
2028 if (__finished())
2029 return __first;
2030
2031 __format::__failed_to_parse_format_spec();
2032 }
2033
2034 template<typename _Fp, typename _Out>
2035 typename basic_format_context<_Out, _CharT>::iterator
2036 format(_Fp __v, basic_format_context<_Out, _CharT>& __fc) const
2037 {
2038 std::string __dynbuf;
2039 char __buf[128];
2040 to_chars_result __res{};
2041
2042 size_t __prec = 6;
2043 bool __use_prec = _M_spec._M_prec_kind != _WP_none;
2044 if (__use_prec)
2045 __prec = _M_spec._M_get_precision(__fc);
2046
2047 char* __start = __buf + 1; // reserve space for sign
2048 char* __end = __buf + sizeof(__buf);
2049
2050 chars_format __fmt{};
2051 bool __upper = false;
2052 bool __trailing_zeros = false;
2053 char __expc = 'e';
2054
2055 switch (_M_spec._M_type)
2056 {
2057 case _Pres_A:
2058 __upper = true;
2059 __expc = 'P';
2060 [[fallthrough]];
2061 case _Pres_a:
2062 if (_M_spec._M_type != _Pres_A)
2063 __expc = 'p';
2064 __fmt = chars_format::hex;
2065 break;
2066 case _Pres_E:
2067 __upper = true;
2068 __expc = 'E';
2069 [[fallthrough]];
2070 case _Pres_e:
2071 __use_prec = true;
2072 __fmt = chars_format::scientific;
2073 break;
2074 case _Pres_F:
2075 __upper = true;
2076 [[fallthrough]];
2077 case _Pres_f:
2078 __use_prec = true;
2079 __fmt = chars_format::fixed;
2080 break;
2081 case _Pres_G:
2082 __upper = true;
2083 __expc = 'E';
2084 [[fallthrough]];
2085 case _Pres_g:
2086 __trailing_zeros = true;
2087 __use_prec = true;
2088 __fmt = chars_format::general;
2089 break;
2090 case _Pres_none:
2091 if (__use_prec)
2092 __fmt = chars_format::general;
2093 break;
2094 default:
2095 __builtin_unreachable();
2096 }
2097
2098 // Write value into buffer using std::to_chars.
2099 auto __to_chars = [&](char* __b, char* __e) {
2100 if (__use_prec)
2101 return __format::to_chars(__b, __e, __v, __fmt, __prec);
2102 else if (__fmt != chars_format{})
2103 return __format::to_chars(__b, __e, __v, __fmt);
2104 else
2105 return __format::to_chars(__b, __e, __v);
2106 };
2107
2108 // First try using stack buffer.
2109 __res = __to_chars(__start, __end);
2110
2111 if (__builtin_expect(__res.ec == errc::value_too_large, 0))
2112 {
2113 // If the buffer is too small it's probably because of a large
2114 // precision, or a very large value in fixed format.
2115 size_t __guess = 8 + __prec;
2116 if (__fmt == chars_format::fixed) // +ddd.prec
2117 {
2118 if constexpr (is_same_v<_Fp, float> || is_same_v<_Fp, double>
2119 || is_same_v<_Fp, long double>)
2120 {
2121 // The number of digits to the left of the decimal point
2122 // is floor(log10(max(abs(__v),1)))+1
2123 int __exp{};
2124 if constexpr (is_same_v<_Fp, float>)
2125 __builtin_frexpf(__v, &__exp);
2126 else if constexpr (is_same_v<_Fp, double>)
2127 __builtin_frexp(__v, &__exp);
2128 else if constexpr (is_same_v<_Fp, long double>)
2129 __builtin_frexpl(__v, &__exp);
2130 if (__exp > 0)
2131 __guess += 1U + __exp * 4004U / 13301U; // log10(2) approx.
2132 }
2133 else
2134 __guess += numeric_limits<_Fp>::max_exponent10;
2135 }
2136 if (__guess <= sizeof(__buf)) [[unlikely]]
2137 __guess = sizeof(__buf) * 2;
2138 __dynbuf.reserve(__guess);
2139
2140 do
2141 {
2142 // Mangling of this lambda, and thus resize_and_overwrite
2143 // instantiated with it, was fixed in ABI 18 (G++ 13). Since
2144 // <format> was new in G++ 13, and is experimental, that
2145 // isn't a problem.
2146 auto __overwrite = [&__to_chars, &__res] (char* __p, size_t __n)
2147 {
2148 __res = __to_chars(__p + 1, __p + __n - 1);
2149 return __res.ec == errc{} ? __res.ptr - __p : 0;
2150 };
2151
2152 __dynbuf.__resize_and_overwrite(__dynbuf.capacity() * 2,
2153 __overwrite);
2154 __start = __dynbuf.data() + 1; // reserve space for sign
2155 __end = __dynbuf.data() + __dynbuf.size();
2156 }
2157 while (__builtin_expect(__res.ec == errc::value_too_large, 0));
2158 }
2159
2160 // Use uppercase for 'A', 'E', and 'G' formats.
2161 if (__upper)
2162 {
2163 for (char* __p = __start; __p != __res.ptr; ++__p)
2164 *__p = std::toupper(*__p);
2165 }
2166
2167 bool __have_sign = true;
2168 // Add sign for non-negative values.
2169 if (!__builtin_signbit(__v))
2170 {
2171 if (_M_spec._M_sign == _Sign_plus)
2172 *--__start = '+';
2173 else if (_M_spec._M_sign == _Sign_space)
2174 *--__start = ' ';
2175 else
2176 __have_sign = false;
2177 }
2178
2179 string_view __narrow_str(__start, __res.ptr - __start);
2180
2181 // Use alternate form. Ensure decimal point is always present,
2182 // and add trailing zeros (up to precision) for g and G forms.
2183 if (_M_spec._M_alt && __builtin_isfinite(__v))
2184 {
2185 string_view __s = __narrow_str;
2186 size_t __sigfigs; // Number of significant figures.
2187 size_t __z = 0; // Number of trailing zeros to add.
2188 size_t __p; // Position of the exponent character (if any).
2189 size_t __d = __s.find('.'); // Position of decimal point.
2190 if (__d != __s.npos) // Found decimal point.
2191 {
2192 __p = __s.find(__expc, __d + 1);
2193 if (__p == __s.npos)
2194 __p = __s.size();
2195
2196 // If presentation type is g or G we might need to add zeros.
2197 if (__trailing_zeros)
2198 {
2199 // Find number of digits after first significant figure.
2200 if (__s[__have_sign] != '0')
2201 // A string like "D.D" or "-D.DDD"
2202 __sigfigs = __p - __have_sign - 1;
2203 else
2204 // A string like "0.D" or "-0.0DD".
2205 // Safe to assume there is a non-zero digit, because
2206 // otherwise there would be no decimal point.
2207 __sigfigs = __p - __s.find_first_not_of('0', __d + 1);
2208 }
2209 }
2210 else // No decimal point, we need to insert one.
2211 {
2212 __p = __s.find(__expc); // Find the exponent, if present.
2213 if (__p == __s.npos)
2214 __p = __s.size();
2215 __d = __p; // Position where '.' should be inserted.
2216 __sigfigs = __d - __have_sign;
2217 }
2218
2219 if (__trailing_zeros && __prec != 0)
2220 {
2221 // For g and G presentation types std::to_chars produces
2222 // no more than prec significant figures. Insert this many
2223 // zeros so the result has exactly prec significant figures.
2224 __z = __prec - __sigfigs;
2225 }
2226
2227 if (size_t __extras = int(__d == __p) + __z) // How many to add.
2228 {
2229 if (__dynbuf.empty() && __extras <= size_t(__end - __res.ptr))
2230 {
2231 // The stack buffer is large enough for the result.
2232 // Move exponent to make space for extra chars.
2233 __builtin_memmove(__start + __p + __extras,
2234 __start + __p,
2235 __s.size() - __p);
2236 if (__d == __p)
2237 __start[__p++] = '.';
2238 __builtin_memset(__start + __p, '0', __z);
2239 __narrow_str = {__s.data(), __s.size() + __extras};
2240 }
2241 else // Need to switch to the dynamic buffer.
2242 {
2243 __dynbuf.reserve(__s.size() + __extras);
2244 if (__dynbuf.empty())
2245 {
2246 __dynbuf = __s.substr(0, __p);
2247 if (__d == __p)
2248 __dynbuf += '.';
2249 if (__z)
2250 __dynbuf.append(__z, '0');
2251 __dynbuf.append(__s.substr(__p));
2252 }
2253 else
2254 {
2255 __dynbuf.insert(__p, __extras, '0');
2256 if (__d == __p)
2257 __dynbuf[__p] = '.';
2258 }
2259 __narrow_str = __dynbuf;
2260 }
2261 }
2262 }
2263
2264 basic_string<_CharT> __wstr;
2265 basic_string_view<_CharT> __str;
2266 if constexpr (is_same_v<_CharT, char>)
2267 __str = __narrow_str;
2268#ifdef _GLIBCXX_USE_WCHAR_T
2269 else
2270 {
2271 __wstr = std::__to_wstring_numeric(__narrow_str);
2272 __str = __wstr;
2273 }
2274#endif
2275
2276 if (_M_spec._M_localized && __builtin_isfinite(__v))
2277 {
2278 auto __s = _M_localize(__str, __expc, __fc.locale());
2279 if (!__s.empty())
2280 __str = __wstr = std::move(__s);
2281 }
2282
2283 size_t __width = _M_spec._M_get_width(__fc);
2284
2285 if (__width <= __str.size())
2286 return __format::__write(__fc.out(), __str);
2287
2288 char32_t __fill_char = _M_spec._M_fill;
2289 _Align __align = _M_spec._M_align;
2290
2291 size_t __nfill = __width - __str.size();
2292 auto __out = __fc.out();
2293 if (__align == _Align_default)
2294 {
2295 __align = _Align_right;
2296 if (_M_spec._M_zero_fill && __builtin_isfinite(__v))
2297 {
2298 __fill_char = _CharT('0');
2299 // Write sign before zero filling.
2300 if (!__format::__is_xdigit(__narrow_str[0]))
2301 {
2302 *__out++ = __str[0];
2303 __str.remove_prefix(1);
2304 }
2305 }
2306 else
2307 __fill_char = _CharT(' ');
2308 }
2309 return __format::__write_padded(std::move(__out), __str,
2310 __align, __nfill, __fill_char);
2311 }
2312
2313 // Locale-specific format.
2314 basic_string<_CharT>
2315 _M_localize(basic_string_view<_CharT> __str, char __expc,
2316 const locale& __loc) const
2317 {
2318 basic_string<_CharT> __lstr;
2319
2320 if (__loc == locale::classic())
2321 return __lstr; // Nothing to do.
2322
2323 const auto& __np = use_facet<numpunct<_CharT>>(__loc);
2324 const _CharT __point = __np.decimal_point();
2325 const string __grp = __np.grouping();
2326
2327 _CharT __dot, __exp;
2328 if constexpr (is_same_v<_CharT, char>)
2329 {
2330 __dot = '.';
2331 __exp = __expc;
2332 }
2333 else
2334 {
2335 __dot = L'.';
2336 switch (__expc)
2337 {
2338 case 'e':
2339 __exp = L'e';
2340 break;
2341 case 'E':
2342 __exp = L'E';
2343 break;
2344 case 'p':
2345 __exp = L'p';
2346 break;
2347 case 'P':
2348 __exp = L'P';
2349 break;
2350 default:
2351 __builtin_unreachable();
2352 }
2353 }
2354
2355 if (__grp.empty() && __point == __dot)
2356 return __lstr; // Locale uses '.' and no grouping.
2357
2358 size_t __d = __str.find(__dot); // Index of radix character (if any).
2359 size_t __e = min(__d, __str.find(__exp)); // First of radix or exponent
2360 if (__e == __str.npos)
2361 __e = __str.size();
2362 const size_t __r = __str.size() - __e; // Length of remainder.
2363 auto __overwrite = [&](_CharT* __p, size_t) {
2364 // Apply grouping to the digits before the radix or exponent.
2365 int __off = 0;
2366 if (auto __c = __str.front(); __c == '-' || __c == '+' || __c == ' ')
2367 {
2368 *__p = __c;
2369 __off = 1;
2370 }
2371 auto __end = std::__add_grouping(__p + __off, __np.thousands_sep(),
2372 __grp.data(), __grp.size(),
2373 __str.data() + __off,
2374 __str.data() + __e);
2375 if (__r) // If there's a fractional part or exponent
2376 {
2377 if (__d != __str.npos)
2378 {
2379 *__end = __point; // Add the locale's radix character.
2380 ++__end;
2381 ++__e;
2382 }
2383 const size_t __rlen = __str.size() - __e;
2384 // Append fractional digits and/or exponent:
2385 char_traits<_CharT>::copy(__end, __str.data() + __e, __rlen);
2386 __end += __rlen;
2387 }
2388 return (__end - __p);
2389 };
2390 __lstr.__resize_and_overwrite(__e * 2 + __r, __overwrite);
2391 return __lstr;
2392 }
2393
2394 _Spec<_CharT> _M_spec{};
2395 };
2396
2397} // namespace __format
2398/// @endcond
2399
2400 /// Format a character.
2401 template<__format::__char _CharT>
2402 struct formatter<_CharT, _CharT>
2403 {
2404 formatter() = default;
2405
2406 constexpr typename basic_format_parse_context<_CharT>::iterator
2407 parse(basic_format_parse_context<_CharT>& __pc)
2408 {
2409 return _M_f.template _M_parse<_CharT>(__pc);
2410 }
2411
2412 template<typename _Out>
2413 typename basic_format_context<_Out, _CharT>::iterator
2414 format(_CharT __u, basic_format_context<_Out, _CharT>& __fc) const
2415 {
2416 if (_M_f._M_spec._M_type == __format::_Pres_none
2417 || _M_f._M_spec._M_type == __format::_Pres_c)
2418 return _M_f._M_format_character(__u, __fc);
2419 else if (_M_f._M_spec._M_type == __format::_Pres_esc)
2420 return _M_f._M_format_character_escaped(__u, __fc);
2421 else
2422 return _M_f.format(static_cast<make_unsigned_t<_CharT>>(__u), __fc);
2423 }
2424
2425#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2426 constexpr void
2427 set_debug_format() noexcept
2428 { _M_f._M_spec._M_type = __format::_Pres_esc; }
2429#endif
2430
2431 private:
2432 __format::__formatter_int<_CharT> _M_f;
2433 };
2434
2435#ifdef _GLIBCXX_USE_WCHAR_T
2436 /// Format a char value for wide character output.
2437 template<>
2438 struct formatter<char, wchar_t>
2439 {
2440 formatter() = default;
2441
2442 constexpr typename basic_format_parse_context<wchar_t>::iterator
2443 parse(basic_format_parse_context<wchar_t>& __pc)
2444 {
2445 return _M_f._M_parse<char>(__pc);
2446 }
2447
2448 template<typename _Out>
2449 typename basic_format_context<_Out, wchar_t>::iterator
2450 format(char __u, basic_format_context<_Out, wchar_t>& __fc) const
2451 {
2452 if (_M_f._M_spec._M_type == __format::_Pres_none
2453 || _M_f._M_spec._M_type == __format::_Pres_c)
2454 return _M_f._M_format_character(__u, __fc);
2455 else if (_M_f._M_spec._M_type == __format::_Pres_esc)
2456 return _M_f._M_format_character_escaped(__u, __fc);
2457 else
2458 return _M_f.format(static_cast<unsigned char>(__u), __fc);
2459 }
2460
2461#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2462 constexpr void
2463 set_debug_format() noexcept
2464 { _M_f._M_spec._M_type = __format::_Pres_esc; }
2465#endif
2466
2467 private:
2468 __format::__formatter_int<wchar_t> _M_f;
2469 };
2470#endif // USE_WCHAR_T
2471
2472 /** Format a string.
2473 * @{
2474 */
2475 template<__format::__char _CharT>
2476 struct formatter<_CharT*, _CharT>
2477 {
2478 formatter() = default;
2479
2480 [[__gnu__::__always_inline__]]
2481 constexpr typename basic_format_parse_context<_CharT>::iterator
2482 parse(basic_format_parse_context<_CharT>& __pc)
2483 { return _M_f.parse(__pc); }
2484
2485 template<typename _Out>
2486 [[__gnu__::__nonnull__]]
2487 typename basic_format_context<_Out, _CharT>::iterator
2488 format(_CharT* __u, basic_format_context<_Out, _CharT>& __fc) const
2489 { return _M_f.format(__u, __fc); }
2490
2491#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2492 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2493#endif
2494
2495 private:
2496 __format::__formatter_str<_CharT> _M_f;
2497 };
2498
2499 template<__format::__char _CharT>
2500 struct formatter<const _CharT*, _CharT>
2501 {
2502 formatter() = default;
2503
2504 [[__gnu__::__always_inline__]]
2505 constexpr typename basic_format_parse_context<_CharT>::iterator
2506 parse(basic_format_parse_context<_CharT>& __pc)
2507 { return _M_f.parse(__pc); }
2508
2509 template<typename _Out>
2510 [[__gnu__::__nonnull__]]
2511 typename basic_format_context<_Out, _CharT>::iterator
2512 format(const _CharT* __u,
2513 basic_format_context<_Out, _CharT>& __fc) const
2514 { return _M_f.format(__u, __fc); }
2515
2516#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2517 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2518#endif
2519
2520 private:
2521 __format::__formatter_str<_CharT> _M_f;
2522 };
2523
2524 template<__format::__char _CharT, size_t _Nm>
2525 struct formatter<_CharT[_Nm], _CharT>
2526 {
2527 formatter() = default;
2528
2529 [[__gnu__::__always_inline__]]
2530 constexpr typename basic_format_parse_context<_CharT>::iterator
2531 parse(basic_format_parse_context<_CharT>& __pc)
2532 { return _M_f.parse(__pc); }
2533
2534 template<typename _Out>
2535 typename basic_format_context<_Out, _CharT>::iterator
2536 format(const _CharT (&__u)[_Nm],
2537 basic_format_context<_Out, _CharT>& __fc) const
2538 { return _M_f.format({__u, _Nm}, __fc); }
2539
2540#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2541 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2542#endif
2543
2544 private:
2545 __format::__formatter_str<_CharT> _M_f;
2546 };
2547
2548 template<typename _Traits, typename _Alloc>
2549 struct formatter<basic_string<char, _Traits, _Alloc>, char>
2550 {
2551 formatter() = default;
2552
2553 [[__gnu__::__always_inline__]]
2554 constexpr typename basic_format_parse_context<char>::iterator
2555 parse(basic_format_parse_context<char>& __pc)
2556 { return _M_f.parse(__pc); }
2557
2558 template<typename _Out>
2559 typename basic_format_context<_Out, char>::iterator
2560 format(const basic_string<char, _Traits, _Alloc>& __u,
2561 basic_format_context<_Out, char>& __fc) const
2562 { return _M_f.format(__u, __fc); }
2563
2564#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2565 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2566#endif
2567
2568 private:
2569 __format::__formatter_str<char> _M_f;
2570 };
2571
2572#ifdef _GLIBCXX_USE_WCHAR_T
2573 template<typename _Traits, typename _Alloc>
2574 struct formatter<basic_string<wchar_t, _Traits, _Alloc>, wchar_t>
2575 {
2576 formatter() = default;
2577
2578 [[__gnu__::__always_inline__]]
2579 constexpr typename basic_format_parse_context<wchar_t>::iterator
2580 parse(basic_format_parse_context<wchar_t>& __pc)
2581 { return _M_f.parse(__pc); }
2582
2583 template<typename _Out>
2584 typename basic_format_context<_Out, wchar_t>::iterator
2585 format(const basic_string<wchar_t, _Traits, _Alloc>& __u,
2586 basic_format_context<_Out, wchar_t>& __fc) const
2587 { return _M_f.format(__u, __fc); }
2588
2589#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2590 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2591#endif
2592
2593 private:
2594 __format::__formatter_str<wchar_t> _M_f;
2595 };
2596#endif // USE_WCHAR_T
2597
2598 template<typename _Traits>
2599 struct formatter<basic_string_view<char, _Traits>, char>
2600 {
2601 formatter() = default;
2602
2603 [[__gnu__::__always_inline__]]
2604 constexpr typename basic_format_parse_context<char>::iterator
2605 parse(basic_format_parse_context<char>& __pc)
2606 { return _M_f.parse(__pc); }
2607
2608 template<typename _Out>
2609 typename basic_format_context<_Out, char>::iterator
2610 format(basic_string_view<char, _Traits> __u,
2611 basic_format_context<_Out, char>& __fc) const
2612 { return _M_f.format(__u, __fc); }
2613
2614#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2615 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2616#endif
2617
2618 private:
2619 __format::__formatter_str<char> _M_f;
2620 };
2621
2622#ifdef _GLIBCXX_USE_WCHAR_T
2623 template<typename _Traits>
2624 struct formatter<basic_string_view<wchar_t, _Traits>, wchar_t>
2625 {
2626 formatter() = default;
2627
2628 [[__gnu__::__always_inline__]]
2629 constexpr typename basic_format_parse_context<wchar_t>::iterator
2630 parse(basic_format_parse_context<wchar_t>& __pc)
2631 { return _M_f.parse(__pc); }
2632
2633 template<typename _Out>
2634 typename basic_format_context<_Out, wchar_t>::iterator
2635 format(basic_string_view<wchar_t, _Traits> __u,
2636 basic_format_context<_Out, wchar_t>& __fc) const
2637 { return _M_f.format(__u, __fc); }
2638
2639#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
2640 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2641#endif
2642
2643 private:
2644 __format::__formatter_str<wchar_t> _M_f;
2645 };
2646#endif // USE_WCHAR_T
2647 /// @}
2648
2649/// @cond undocumented
2650namespace __format
2651{
2652 // each cv-unqualified arithmetic type ArithmeticT other than
2653 // char, wchar_t, char8_t, char16_t, or char32_t
2654 template<typename _Tp>
2655 constexpr bool __is_formattable_integer = __is_integer<_Tp>::__value;
2656
2657#if defined __SIZEOF_INT128__
2658 template<> inline constexpr bool __is_formattable_integer<__int128> = true;
2659 template<> inline constexpr bool __is_formattable_integer<unsigned __int128>
2660 = true;
2661#endif
2662
2663 template<> inline constexpr bool __is_formattable_integer<char> = false;
2664 template<> inline constexpr bool __is_formattable_integer<wchar_t> = false;
2665#ifdef _GLIBCXX_USE_CHAR8_T
2666 template<> inline constexpr bool __is_formattable_integer<char8_t> = false;
2667#endif
2668 template<> inline constexpr bool __is_formattable_integer<char16_t> = false;
2669 template<> inline constexpr bool __is_formattable_integer<char32_t> = false;
2670}
2671/// @endcond
2672
2673 /// Format an integer.
2674 template<typename _Tp, __format::__char _CharT>
2675 requires __format::__is_formattable_integer<_Tp>
2676 struct formatter<_Tp, _CharT>
2677 {
2678 formatter() = default;
2679
2680 [[__gnu__::__always_inline__]]
2681 constexpr typename basic_format_parse_context<_CharT>::iterator
2682 parse(basic_format_parse_context<_CharT>& __pc)
2683 {
2684 return _M_f.template _M_parse<_Tp>(__pc);
2685 }
2686
2687 template<typename _Out>
2688 typename basic_format_context<_Out, _CharT>::iterator
2689 format(_Tp __u, basic_format_context<_Out, _CharT>& __fc) const
2690 { return _M_f.format(__u, __fc); }
2691
2692 private:
2693 __format::__formatter_int<_CharT> _M_f;
2694 };
2695
2696#if defined __glibcxx_to_chars
2697 /// Format a floating-point value.
2698 template<__format::__formattable_float _Tp, __format::__char _CharT>
2699 struct formatter<_Tp, _CharT>
2700 {
2701 formatter() = default;
2702
2703 [[__gnu__::__always_inline__]]
2704 constexpr typename basic_format_parse_context<_CharT>::iterator
2705 parse(basic_format_parse_context<_CharT>& __pc)
2706 { return _M_f.parse(__pc); }
2707
2708 template<typename _Out>
2709 typename basic_format_context<_Out, _CharT>::iterator
2710 format(_Tp __u, basic_format_context<_Out, _CharT>& __fc) const
2711 { return _M_f.format(__u, __fc); }
2712
2713 private:
2714 __format::__formatter_fp<_CharT> _M_f;
2715 };
2716
2717#if __LDBL_MANT_DIG__ == __DBL_MANT_DIG__
2718 // Reuse __formatter_fp<C>::format<double, Out> for long double.
2719 template<__format::__char _CharT>
2720 struct formatter<long double, _CharT>
2721 {
2722 formatter() = default;
2723
2724 [[__gnu__::__always_inline__]]
2725 constexpr typename basic_format_parse_context<_CharT>::iterator
2726 parse(basic_format_parse_context<_CharT>& __pc)
2727 { return _M_f.parse(__pc); }
2728
2729 template<typename _Out>
2730 typename basic_format_context<_Out, _CharT>::iterator
2731 format(long double __u, basic_format_context<_Out, _CharT>& __fc) const
2732 { return _M_f.format((double)__u, __fc); }
2733
2734 private:
2735 __format::__formatter_fp<_CharT> _M_f;
2736 };
2737#endif
2738
2739#if defined(__STDCPP_FLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
2740 // Reuse __formatter_fp<C>::format<float, Out> for _Float16.
2741 template<__format::__char _CharT>
2742 struct formatter<_Float16, _CharT>
2743 {
2744 formatter() = default;
2745
2746 [[__gnu__::__always_inline__]]
2747 constexpr typename basic_format_parse_context<_CharT>::iterator
2748 parse(basic_format_parse_context<_CharT>& __pc)
2749 { return _M_f.parse(__pc); }
2750
2751 template<typename _Out>
2752 typename basic_format_context<_Out, _CharT>::iterator
2753 format(_Float16 __u, basic_format_context<_Out, _CharT>& __fc) const
2754 { return _M_f.format((float)__u, __fc); }
2755
2756 private:
2757 __format::__formatter_fp<_CharT> _M_f;
2758 };
2759#endif
2760
2761#if defined(__FLT32_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
2762 // Reuse __formatter_fp<C>::format<float, Out> for _Float32.
2763 template<__format::__char _CharT>
2764 struct formatter<_Float32, _CharT>
2765 {
2766 formatter() = default;
2767
2768 [[__gnu__::__always_inline__]]
2769 constexpr typename basic_format_parse_context<_CharT>::iterator
2770 parse(basic_format_parse_context<_CharT>& __pc)
2771 { return _M_f.parse(__pc); }
2772
2773 template<typename _Out>
2774 typename basic_format_context<_Out, _CharT>::iterator
2775 format(_Float32 __u, basic_format_context<_Out, _CharT>& __fc) const
2776 { return _M_f.format((float)__u, __fc); }
2777
2778 private:
2779 __format::__formatter_fp<_CharT> _M_f;
2780 };
2781#endif
2782
2783#if defined(__FLT64_DIG__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
2784 // Reuse __formatter_fp<C>::format<double, Out> for _Float64.
2785 template<__format::__char _CharT>
2786 struct formatter<_Float64, _CharT>
2787 {
2788 formatter() = default;
2789
2790 [[__gnu__::__always_inline__]]
2791 constexpr typename basic_format_parse_context<_CharT>::iterator
2792 parse(basic_format_parse_context<_CharT>& __pc)
2793 { return _M_f.parse(__pc); }
2794
2795 template<typename _Out>
2796 typename basic_format_context<_Out, _CharT>::iterator
2797 format(_Float64 __u, basic_format_context<_Out, _CharT>& __fc) const
2798 { return _M_f.format((double)__u, __fc); }
2799
2800 private:
2801 __format::__formatter_fp<_CharT> _M_f;
2802 };
2803#endif
2804
2805#if defined(__FLT128_DIG__) && _GLIBCXX_FORMAT_F128 == 1
2806 // Reuse __formatter_fp<C>::format<__float128_t, Out> for _Float128.
2807 template<__format::__char _CharT>
2808 struct formatter<_Float128, _CharT>
2809 {
2810 formatter() = default;
2811
2812 [[__gnu__::__always_inline__]]
2813 constexpr typename basic_format_parse_context<_CharT>::iterator
2814 parse(basic_format_parse_context<_CharT>& __pc)
2815 { return _M_f.parse(__pc); }
2816
2817 template<typename _Out>
2818 typename basic_format_context<_Out, _CharT>::iterator
2819 format(_Float128 __u, basic_format_context<_Out, _CharT>& __fc) const
2820 { return _M_f.format((__format::__float128_t)__u, __fc); }
2821
2822 private:
2823 __format::__formatter_fp<_CharT> _M_f;
2824 };
2825#endif
2826
2827#if defined(__STDCPP_BFLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
2828 // Reuse __formatter_fp<C>::format<float, Out> for bfloat16_t.
2829 template<__format::__char _CharT>
2830 struct formatter<__gnu_cxx::__bfloat16_t, _CharT>
2831 {
2832 formatter() = default;
2833
2834 [[__gnu__::__always_inline__]]
2835 constexpr typename basic_format_parse_context<_CharT>::iterator
2836 parse(basic_format_parse_context<_CharT>& __pc)
2837 { return _M_f.parse(__pc); }
2838
2839 template<typename _Out>
2840 typename basic_format_context<_Out, _CharT>::iterator
2841 format(__gnu_cxx::__bfloat16_t __u,
2842 basic_format_context<_Out, _CharT>& __fc) const
2843 { return _M_f.format((float)__u, __fc); }
2844
2845 private:
2846 __format::__formatter_fp<_CharT> _M_f;
2847 };
2848#endif
2849#endif // __cpp_lib_to_chars
2850
2851 /** Format a pointer.
2852 * @{
2853 */
2854 template<__format::__char _CharT>
2855 struct formatter<const void*, _CharT>
2856 {
2857 formatter() = default;
2858
2859 constexpr typename basic_format_parse_context<_CharT>::iterator
2860 parse(basic_format_parse_context<_CharT>& __pc)
2861 {
2862 __format::_Spec<_CharT> __spec{};
2863 const auto __last = __pc.end();
2864 auto __first = __pc.begin();
2865
2866 auto __finalize = [this, &__spec] {
2867 _M_spec = __spec;
2868 };
2869
2870 auto __finished = [&] {
2871 if (__first == __last || *__first == '}')
2872 {
2873 __finalize();
2874 return true;
2875 }
2876 return false;
2877 };
2878
2879 if (__finished())
2880 return __first;
2881
2882 __first = __spec._M_parse_fill_and_align(__first, __last);
2883 if (__finished())
2884 return __first;
2885
2886// _GLIBCXX_RESOLVE_LIB_DEFECTS
2887// P2510R3 Formatting pointers
2888#if __glibcxx_format >= 202304L
2889 __first = __spec._M_parse_zero_fill(__first, __last);
2890 if (__finished())
2891 return __first;
2892#endif
2893
2894 __first = __spec._M_parse_width(__first, __last, __pc);
2895
2896 if (__first != __last)
2897 {
2898 if (*__first == 'p')
2899 ++__first;
2900#if __glibcxx_format >= 202304L
2901 else if (*__first == 'P')
2902 {
2903 __spec._M_type = __format::_Pres_P;
2904 ++__first;
2905 }
2906#endif
2907 }
2908
2909 if (__finished())
2910 return __first;
2911
2912 __format::__failed_to_parse_format_spec();
2913 }
2914
2915 template<typename _Out>
2916 typename basic_format_context<_Out, _CharT>::iterator
2917 format(const void* __v, basic_format_context<_Out, _CharT>& __fc) const
2918 {
2919 auto __u = reinterpret_cast<__UINTPTR_TYPE__>(__v);
2920 char __buf[2 + sizeof(__v) * 2];
2921 auto [__ptr, __ec] = std::to_chars(__buf + 2, std::end(__buf),
2922 __u, 16);
2923 int __n = __ptr - __buf;
2924 __buf[0] = '0';
2925 __buf[1] = 'x';
2926#if __glibcxx_format >= 202304L
2927 if (_M_spec._M_type == __format::_Pres_P)
2928 {
2929 __buf[1] = 'X';
2930 for (auto __p = __buf + 2; __p != __ptr; ++__p)
2931#if __has_builtin(__builtin_toupper)
2932 *__p = __builtin_toupper(*__p);
2933#else
2934 *__p = std::toupper(*__p);
2935#endif
2936 }
2937#endif
2938
2940 if constexpr (is_same_v<_CharT, char>)
2941 __str = string_view(__buf, __n);
2942#ifdef _GLIBCXX_USE_WCHAR_T
2943 else
2944 {
2945 auto __p = (_CharT*)__builtin_alloca(__n * sizeof(_CharT));
2946 std::__to_wstring_numeric(__buf, __n, __p);
2947 __str = wstring_view(__p, __n);
2948 }
2949#endif
2950
2951#if __glibcxx_format >= 202304L
2952 if (_M_spec._M_zero_fill)
2953 {
2954 size_t __width = _M_spec._M_get_width(__fc);
2955 if (__width <= __str.size())
2956 return __format::__write(__fc.out(), __str);
2957
2958 auto __out = __fc.out();
2959 // Write "0x" or "0X" prefix before zero-filling.
2960 __out = __format::__write(std::move(__out), __str.substr(0, 2));
2961 __str.remove_prefix(2);
2962 size_t __nfill = __width - __n;
2963 return __format::__write_padded(std::move(__out), __str,
2964 __format::_Align_right,
2965 __nfill, _CharT('0'));
2966 }
2967#endif
2968
2969 return __format::__write_padded_as_spec(__str, __n, __fc, _M_spec,
2970 __format::_Align_right);
2971 }
2972
2973 private:
2974 __format::_Spec<_CharT> _M_spec{};
2975 };
2976
2977 template<__format::__char _CharT>
2978 struct formatter<void*, _CharT>
2979 {
2980 formatter() = default;
2981
2982 [[__gnu__::__always_inline__]]
2983 constexpr typename basic_format_parse_context<_CharT>::iterator
2984 parse(basic_format_parse_context<_CharT>& __pc)
2985 { return _M_f.parse(__pc); }
2986
2987 template<typename _Out>
2988 typename basic_format_context<_Out, _CharT>::iterator
2989 format(void* __v, basic_format_context<_Out, _CharT>& __fc) const
2990 { return _M_f.format(__v, __fc); }
2991
2992 private:
2993 formatter<const void*, _CharT> _M_f;
2994 };
2995
2996 template<__format::__char _CharT>
2997 struct formatter<nullptr_t, _CharT>
2998 {
2999 formatter() = default;
3000
3001 [[__gnu__::__always_inline__]]
3002 constexpr typename basic_format_parse_context<_CharT>::iterator
3003 parse(basic_format_parse_context<_CharT>& __pc)
3004 { return _M_f.parse(__pc); }
3005
3006 template<typename _Out>
3007 typename basic_format_context<_Out, _CharT>::iterator
3008 format(nullptr_t, basic_format_context<_Out, _CharT>& __fc) const
3009 { return _M_f.format(nullptr, __fc); }
3010
3011 private:
3012 formatter<const void*, _CharT> _M_f;
3013 };
3014 /// @}
3015
3016#if defined _GLIBCXX_USE_WCHAR_T && __glibcxx_format_ranges
3017 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3018 // 3944. Formatters converting sequences of char to sequences of wchar_t
3019
3020 struct __formatter_disabled
3021 {
3022 __formatter_disabled() = delete; // Cannot format char sequence to wchar_t
3023 __formatter_disabled(const __formatter_disabled&) = delete;
3024 __formatter_disabled& operator=(const __formatter_disabled&) = delete;
3025 };
3026
3027 template<>
3028 struct formatter<char*, wchar_t>
3029 : private __formatter_disabled { };
3030 template<>
3031 struct formatter<const char*, wchar_t>
3032 : private __formatter_disabled { };
3033 template<size_t _Nm>
3034 struct formatter<char[_Nm], wchar_t>
3035 : private __formatter_disabled { };
3036 template<class _Traits, class _Allocator>
3037 struct formatter<basic_string<char, _Traits, _Allocator>, wchar_t>
3038 : private __formatter_disabled { };
3039 template<class _Traits>
3040 struct formatter<basic_string_view<char, _Traits>, wchar_t>
3041 : private __formatter_disabled { };
3042#endif
3043
3044 /// An iterator after the last character written, and the number of
3045 /// characters that would have been written.
3046 template<typename _Out>
3047 struct format_to_n_result
3048 {
3049 _Out out;
3050 iter_difference_t<_Out> size;
3051 };
3052
3053_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
3054template<typename, typename> class vector;
3055_GLIBCXX_END_NAMESPACE_CONTAINER
3056
3057/// @cond undocumented
3058namespace __format
3059{
3060 template<typename _CharT>
3061 class _Sink_iter
3062 {
3063 _Sink<_CharT>* _M_sink = nullptr;
3064
3065 public:
3066 using iterator_category = output_iterator_tag;
3067 using value_type = void;
3068 using difference_type = ptrdiff_t;
3069 using pointer = void;
3070 using reference = void;
3071
3072 _Sink_iter() = default;
3073 _Sink_iter(const _Sink_iter&) = default;
3074 _Sink_iter& operator=(const _Sink_iter&) = default;
3075
3076 [[__gnu__::__always_inline__]]
3077 explicit constexpr
3078 _Sink_iter(_Sink<_CharT>& __sink) : _M_sink(std::addressof(__sink)) { }
3079
3080 [[__gnu__::__always_inline__]]
3081 constexpr _Sink_iter&
3082 operator=(_CharT __c)
3083 {
3084 _M_sink->_M_write(__c);
3085 return *this;
3086 }
3087
3088 [[__gnu__::__always_inline__]]
3089 constexpr _Sink_iter&
3090 operator=(basic_string_view<_CharT> __s)
3091 {
3092 _M_sink->_M_write(__s);
3093 return *this;
3094 }
3095
3096 [[__gnu__::__always_inline__]]
3097 constexpr _Sink_iter&
3098 operator*() { return *this; }
3099
3100 [[__gnu__::__always_inline__]]
3101 constexpr _Sink_iter&
3102 operator++() { return *this; }
3103
3104 [[__gnu__::__always_inline__]]
3105 constexpr _Sink_iter
3106 operator++(int) { return *this; }
3107
3108 auto
3109 _M_reserve(size_t __n) const
3110 { return _M_sink->_M_reserve(__n); }
3111 };
3112
3113 // Abstract base class for type-erased character sinks.
3114 // All formatting and output is done via this type's iterator,
3115 // to reduce the number of different template instantiations.
3116 template<typename _CharT>
3117 class _Sink
3118 {
3119 friend class _Sink_iter<_CharT>;
3120
3121 span<_CharT> _M_span;
3122 typename span<_CharT>::iterator _M_next;
3123
3124 // Called when the span is full, to make more space available.
3125 // Precondition: _M_next != _M_span.begin()
3126 // Postcondition: _M_next != _M_span.end()
3127 // TODO: remove the precondition? could make overflow handle it.
3128 virtual void _M_overflow() = 0;
3129
3130 protected:
3131 // Precondition: __span.size() != 0
3132 [[__gnu__::__always_inline__]]
3133 explicit constexpr
3134 _Sink(span<_CharT> __span) noexcept
3135 : _M_span(__span), _M_next(__span.begin())
3136 { }
3137
3138 // The portion of the span that has been written to.
3139 [[__gnu__::__always_inline__]]
3140 span<_CharT>
3141 _M_used() const noexcept
3142 { return _M_span.first(_M_next - _M_span.begin()); }
3143
3144 // The portion of the span that has not been written to.
3145 [[__gnu__::__always_inline__]]
3146 constexpr span<_CharT>
3147 _M_unused() const noexcept
3148 { return _M_span.subspan(_M_next - _M_span.begin()); }
3149
3150 // Use the start of the span as the next write position.
3151 [[__gnu__::__always_inline__]]
3152 constexpr void
3153 _M_rewind() noexcept
3154 { _M_next = _M_span.begin(); }
3155
3156 // Replace the current output range.
3157 void
3158 _M_reset(span<_CharT> __s, size_t __pos = 0) noexcept
3159 {
3160 _M_span = __s;
3161 _M_next = __s.begin() + __pos;
3162 }
3163
3164 // Called by the iterator for *it++ = c
3165 constexpr void
3166 _M_write(_CharT __c)
3167 {
3168 *_M_next++ = __c;
3169 if (_M_next - _M_span.begin() == std::ssize(_M_span)) [[unlikely]]
3170 _M_overflow();
3171 }
3172
3173 constexpr void
3174 _M_write(basic_string_view<_CharT> __s)
3175 {
3176 span __to = _M_unused();
3177 while (__to.size() <= __s.size())
3178 {
3179 __s.copy(__to.data(), __to.size());
3180 _M_next += __to.size();
3181 __s.remove_prefix(__to.size());
3182 _M_overflow();
3183 __to = _M_unused();
3184 }
3185 if (__s.size())
3186 {
3187 __s.copy(__to.data(), __s.size());
3188 _M_next += __s.size();
3189 }
3190 }
3191
3192 // A successful _Reservation can be used to directly write
3193 // up to N characters to the sink to avoid unwanted buffering.
3194 struct _Reservation
3195 {
3196 // True if the reservation was successful, false otherwise.
3197 explicit operator bool() const noexcept { return _M_sink; }
3198 // A pointer to write directly to the sink.
3199 _CharT* get() const noexcept { return _M_sink->_M_next.operator->(); }
3200 // Add n to the _M_next iterator for the sink.
3201 void _M_bump(size_t __n) { _M_sink->_M_bump(__n); }
3202 _Sink* _M_sink;
3203 };
3204
3205 // Attempt to reserve space to write n characters to the sink.
3206 // If anything is written to the reservation then there must be a call
3207 // to _M_bump(N2) before any call to another member function of *this,
3208 // where N2 is the number of characters written.
3209 virtual _Reservation
3210 _M_reserve(size_t __n)
3211 {
3212 if (__n <= _M_unused().size())
3213 return { this };
3214
3215 if (__n <= _M_span.size()) // Cannot meet the request.
3216 {
3217 _M_overflow(); // Make more space available.
3218 if (__n <= _M_unused().size())
3219 return { this };
3220 }
3221 return { nullptr };
3222 }
3223
3224 // Update the next output position after writing directly to the sink.
3225 // pre: no calls to _M_write or _M_overflow since _M_reserve.
3226 virtual void
3227 _M_bump(size_t __n)
3228 { _M_next += __n; }
3229
3230 public:
3231 _Sink(const _Sink&) = delete;
3232 _Sink& operator=(const _Sink&) = delete;
3233
3234 [[__gnu__::__always_inline__]]
3235 constexpr _Sink_iter<_CharT>
3236 out() noexcept
3237 { return _Sink_iter<_CharT>(*this); }
3238 };
3239
3240
3241 template<typename _CharT>
3242 class _Fixedbuf_sink final : public _Sink<_CharT>
3243 {
3244 void
3245 _M_overflow() override
3246 {
3247 __glibcxx_assert(false);
3248 this->_M_rewind();
3249 }
3250
3251 public:
3252 [[__gnu__::__always_inline__]]
3253 constexpr explicit
3254 _Fixedbuf_sink(span<_CharT> __buf)
3255 : _Sink<_CharT>(__buf)
3256 { }
3257
3258 constexpr basic_string_view<_CharT>
3259 view() const
3260 {
3261 auto __s = this->_M_used();
3262 return basic_string_view<_CharT>(__s.data(), __s.size());
3263 }
3264 };
3265
3266 // A sink with an internal buffer. This is used to implement concrete sinks.
3267 template<typename _CharT>
3268 class _Buf_sink : public _Sink<_CharT>
3269 {
3270 protected:
3271 _CharT _M_buf[__stackbuf_size<_CharT>];
3272
3273 [[__gnu__::__always_inline__]]
3274 constexpr
3275 _Buf_sink() noexcept
3276 : _Sink<_CharT>(_M_buf)
3277 { }
3278 };
3279
3280 using _GLIBCXX_STD_C::vector;
3281
3282 // A sink that fills a sequence (e.g. std::string, std::vector, std::deque).
3283 // Writes to a buffer then appends that to the sequence when it fills up.
3284 template<typename _Seq>
3285 class _Seq_sink final : public _Buf_sink<typename _Seq::value_type>
3286 {
3287 using _CharT = typename _Seq::value_type;
3288
3289 _Seq _M_seq;
3290
3291 // Transfer buffer contents to the sequence, so buffer can be refilled.
3292 void
3293 _M_overflow() override
3294 {
3295 auto __s = this->_M_used();
3296 if (__s.empty()) [[unlikely]]
3297 return; // Nothing in the buffer to transfer to _M_seq.
3298
3299 // If _M_reserve was called then _M_bump must have been called too.
3300 _GLIBCXX_DEBUG_ASSERT(__s.data() != _M_seq.data());
3301
3302 if constexpr (__is_specialization_of<_Seq, basic_string>)
3303 _M_seq.append(__s.data(), __s.size());
3304 else
3305 _M_seq.insert(_M_seq.end(), __s.begin(), __s.end());
3306
3307 // Make the whole of _M_buf available for the next write:
3308 this->_M_rewind();
3309 }
3310
3311 typename _Sink<_CharT>::_Reservation
3312 _M_reserve(size_t __n) override
3313 {
3314 // We might already have n characters available in this->_M_unused(),
3315 // but the whole point of this function is to be an optimization for
3316 // the std::format("{}", x) case. We want to avoid writing to _M_buf
3317 // and then copying that into a basic_string if possible, so this
3318 // function prefers to create space directly in _M_seq rather than
3319 // using _M_buf.
3320
3321 if constexpr (__is_specialization_of<_Seq, basic_string>
3322 || __is_specialization_of<_Seq, vector>)
3323 {
3324 // Flush the buffer to _M_seq first (should not be needed).
3325 if (this->_M_used().size()) [[unlikely]]
3326 _Seq_sink::_M_overflow();
3327
3328 // Expand _M_seq to make __n new characters available:
3329 const auto __sz = _M_seq.size();
3330 if constexpr (is_same_v<string, _Seq> || is_same_v<wstring, _Seq>)
3331 _M_seq.__resize_and_overwrite(__sz + __n,
3332 [](auto, auto __n2) {
3333 return __n2;
3334 });
3335 else
3336 _M_seq.resize(__sz + __n);
3337
3338 // Set _M_used() to be a span over the original part of _M_seq
3339 // and _M_unused() to be the extra capacity we just created:
3340 this->_M_reset(_M_seq, __sz);
3341 return { this };
3342 }
3343 else // Try to use the base class' buffer.
3344 return _Sink<_CharT>::_M_reserve(__n);
3345 }
3346
3347 void
3348 _M_bump(size_t __n) override
3349 {
3350 if constexpr (__is_specialization_of<_Seq, basic_string>
3351 || __is_specialization_of<_Seq, vector>)
3352 {
3353 auto __s = this->_M_used();
3354 _GLIBCXX_DEBUG_ASSERT(__s.data() == _M_seq.data());
3355 // Truncate the sequence to the part that was actually written to:
3356 _M_seq.resize(__s.size() + __n);
3357 // Switch back to using buffer:
3358 this->_M_reset(this->_M_buf);
3359 }
3360 }
3361
3362 public:
3363 // TODO: for SSO string, use SSO buffer as initial span, then switch
3364 // to _M_buf if it overflows? Or even do that for all unused capacity?
3365
3366 [[__gnu__::__always_inline__]]
3367 _Seq_sink() noexcept(is_nothrow_default_constructible_v<_Seq>)
3368 { }
3369
3370 _Seq_sink(_Seq&& __s) noexcept(is_nothrow_move_constructible_v<_Seq>)
3371 : _M_seq(std::move(__s))
3372 { }
3373
3374 using _Sink<_CharT>::out;
3375
3376 _Seq
3377 get() &&
3378 {
3379 if (this->_M_used().size() != 0)
3380 _Seq_sink::_M_overflow();
3381 return std::move(_M_seq);
3382 }
3383
3384 // A writable span that views everything written to the sink.
3385 // Will be either a view over _M_seq or the used part of _M_buf.
3386 span<_CharT>
3387 view()
3388 {
3389 auto __s = this->_M_used();
3390 if (_M_seq.size())
3391 {
3392 if (__s.size() != 0)
3393 _Seq_sink::_M_overflow();
3394 return _M_seq;
3395 }
3396 return __s;
3397 }
3398 };
3399
3400 // A sink that writes to an output iterator.
3401 // Writes to a fixed-size buffer and then flushes to the output iterator
3402 // when the buffer fills up.
3403 template<typename _CharT, typename _OutIter>
3404 class _Iter_sink : public _Buf_sink<_CharT>
3405 {
3406 _OutIter _M_out;
3407 iter_difference_t<_OutIter> _M_max;
3408
3409 protected:
3410 size_t _M_count = 0;
3411
3412 void
3413 _M_overflow() override
3414 {
3415 auto __s = this->_M_used();
3416 if (_M_max < 0) // No maximum.
3417 _M_out = ranges::copy(__s, std::move(_M_out)).out;
3418 else if (_M_count < static_cast<size_t>(_M_max))
3419 {
3420 auto __max = _M_max - _M_count;
3421 span<_CharT> __first;
3422 if (__max < __s.size())
3423 __first = __s.first(static_cast<size_t>(__max));
3424 else
3425 __first = __s;
3426 _M_out = ranges::copy(__first, std::move(_M_out)).out;
3427 }
3428 this->_M_rewind();
3429 _M_count += __s.size();
3430 }
3431
3432 public:
3433 [[__gnu__::__always_inline__]]
3434 explicit
3435 _Iter_sink(_OutIter __out, iter_difference_t<_OutIter> __max = -1)
3436 : _M_out(std::move(__out)), _M_max(__max)
3437 { }
3438
3439 using _Sink<_CharT>::out;
3440
3441 format_to_n_result<_OutIter>
3442 _M_finish() &&
3443 {
3444 if (this->_M_used().size() != 0)
3445 _Iter_sink::_M_overflow();
3446 iter_difference_t<_OutIter> __count(_M_count);
3447 return { std::move(_M_out), __count };
3448 }
3449 };
3450
3451 // Partial specialization for contiguous iterators.
3452 // No buffer is used, characters are written straight to the iterator.
3453 // We do not know the size of the output range, so the span size just grows
3454 // as needed. The end of the span might be an invalid pointer outside the
3455 // valid range, but we never actually call _M_span.end(). This class does
3456 // not introduce any invalid pointer arithmetic or overflows that would not
3457 // have happened anyway.
3458 template<typename _CharT, contiguous_iterator _OutIter>
3459 requires same_as<iter_value_t<_OutIter>, _CharT>
3460 class _Iter_sink<_CharT, _OutIter> : public _Sink<_CharT>
3461 {
3462 _OutIter _M_first;
3463 iter_difference_t<_OutIter> _M_max = -1;
3464 protected:
3465 size_t _M_count = 0;
3466 private:
3467 _CharT _M_buf[64]; // Write here after outputting _M_max characters.
3468
3469 protected:
3470 void
3471 _M_overflow() override
3472 {
3473 if (this->_M_unused().size() != 0)
3474 return; // No need to switch to internal buffer yet.
3475
3476 auto __s = this->_M_used();
3477
3478 if (_M_max >= 0)
3479 {
3480 _M_count += __s.size();
3481 // Span was already sized for the maximum character count,
3482 // if it overflows then any further output must go to the
3483 // internal buffer, to be discarded.
3484 this->_M_reset(this->_M_buf);
3485 }
3486 else
3487 {
3488 // No maximum character count. Just extend the span to allow
3489 // writing more characters to it.
3490 this->_M_reset({__s.data(), __s.size() + 1024}, __s.size());
3491 }
3492 }
3493
3494 typename _Sink<_CharT>::_Reservation
3495 _M_reserve(size_t __n) final
3496 {
3497 auto __avail = this->_M_unused();
3498 if (__n > __avail.size())
3499 {
3500 if (_M_max >= 0)
3501 return {}; // cannot grow
3502
3503 auto __s = this->_M_used();
3504 this->_M_reset({__s.data(), __s.size() + __n}, __s.size());
3505 }
3506 return { this };
3507 }
3508
3509 private:
3510 static span<_CharT>
3511 _S_make_span(_CharT* __ptr, iter_difference_t<_OutIter> __n,
3512 span<_CharT> __buf) noexcept
3513 {
3514 if (__n == 0)
3515 return __buf; // Only write to the internal buffer.
3516
3517 if (__n > 0)
3518 {
3519 if constexpr (!is_integral_v<iter_difference_t<_OutIter>>
3520 || sizeof(__n) > sizeof(size_t))
3521 {
3522 // __int128 or __detail::__max_diff_type
3523 auto __m = iter_difference_t<_OutIter>((size_t)-1);
3524 if (__n > __m)
3525 __n = __m;
3526 }
3527 return {__ptr, (size_t)__n};
3528 }
3529
3530#if __has_builtin(__builtin_dynamic_object_size)
3531 if (size_t __bytes = __builtin_dynamic_object_size(__ptr, 2))
3532 return {__ptr, __bytes / sizeof(_CharT)};
3533#endif
3534 // Avoid forming a pointer to a different memory page.
3535 const auto __off = reinterpret_cast<__UINTPTR_TYPE__>(__ptr) % 1024;
3536 __n = (1024 - __off) / sizeof(_CharT);
3537 if (__n > 0) [[likely]]
3538 return {__ptr, static_cast<size_t>(__n)};
3539 else // Misaligned/packed buffer of wchar_t?
3540 return {__ptr, 1};
3541 }
3542
3543 public:
3544 explicit
3545 _Iter_sink(_OutIter __out, iter_difference_t<_OutIter> __n = -1) noexcept
3546 : _Sink<_CharT>(_S_make_span(std::to_address(__out), __n, _M_buf)),
3547 _M_first(__out), _M_max(__n)
3548 { }
3549
3550 format_to_n_result<_OutIter>
3551 _M_finish() &&
3552 {
3553 auto __s = this->_M_used();
3554 if (__s.data() == _M_buf)
3555 {
3556 // Switched to internal buffer, so must have written _M_max.
3557 iter_difference_t<_OutIter> __count(_M_count + __s.size());
3558 return { _M_first + _M_max, __count };
3559 }
3560 else // Not using internal buffer yet
3561 {
3562 iter_difference_t<_OutIter> __count(__s.size());
3563 return { _M_first + __count, __count };
3564 }
3565 }
3566 };
3567
3568 enum _Arg_t : unsigned char {
3569 _Arg_none, _Arg_bool, _Arg_c, _Arg_i, _Arg_u, _Arg_ll, _Arg_ull,
3570 _Arg_flt, _Arg_dbl, _Arg_ldbl, _Arg_str, _Arg_sv, _Arg_ptr, _Arg_handle,
3571 _Arg_i128, _Arg_u128,
3572 _Arg_bf16, _Arg_f16, _Arg_f32, _Arg_f64, // These are unused.
3573#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3574 _Arg_next_value_,
3575 _Arg_f128 = _Arg_ldbl,
3576 _Arg_ibm128 = _Arg_next_value_,
3577#else
3578 _Arg_f128,
3579#endif
3580 _Arg_max_
3581 };
3582
3583 template<typename _Context>
3584 struct _Arg_value
3585 {
3586 using _CharT = typename _Context::char_type;
3587
3588 struct _HandleBase
3589 {
3590 const void* _M_ptr;
3591 void (*_M_func)();
3592 };
3593
3594 union
3595 {
3596 monostate _M_none;
3597 bool _M_bool;
3598 _CharT _M_c;
3599 int _M_i;
3600 unsigned _M_u;
3601 long long _M_ll;
3602 unsigned long long _M_ull;
3603 float _M_flt;
3604 double _M_dbl;
3605#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT // No long double if it's ambiguous.
3606 long double _M_ldbl;
3607#endif
3608 const _CharT* _M_str;
3609 basic_string_view<_CharT> _M_sv;
3610 const void* _M_ptr;
3611 _HandleBase _M_handle;
3612#ifdef __SIZEOF_INT128__
3613 __int128 _M_i128;
3614 unsigned __int128 _M_u128;
3615#endif
3616#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3617 __ieee128 _M_f128;
3618 __ibm128 _M_ibm128;
3619#elif _GLIBCXX_FORMAT_F128 == 2
3620 __float128_t _M_f128;
3621#endif
3622 };
3623
3624 [[__gnu__::__always_inline__]]
3625 _Arg_value() : _M_none() { }
3626
3627#if 0
3628 template<typename _Tp>
3629 _Arg_value(in_place_type_t<_Tp>, _Tp __val)
3630 { _S_get<_Tp>() = __val; }
3631#endif
3632
3633 template<typename _Tp, typename _Self>
3634 [[__gnu__::__always_inline__]]
3635 static auto&
3636 _S_get(_Self& __u) noexcept
3637 {
3638 if constexpr (is_same_v<_Tp, bool>)
3639 return __u._M_bool;
3640 else if constexpr (is_same_v<_Tp, _CharT>)
3641 return __u._M_c;
3642 else if constexpr (is_same_v<_Tp, int>)
3643 return __u._M_i;
3644 else if constexpr (is_same_v<_Tp, unsigned>)
3645 return __u._M_u;
3646 else if constexpr (is_same_v<_Tp, long long>)
3647 return __u._M_ll;
3648 else if constexpr (is_same_v<_Tp, unsigned long long>)
3649 return __u._M_ull;
3650 else if constexpr (is_same_v<_Tp, float>)
3651 return __u._M_flt;
3652 else if constexpr (is_same_v<_Tp, double>)
3653 return __u._M_dbl;
3654#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3655 else if constexpr (is_same_v<_Tp, long double>)
3656 return __u._M_ldbl;
3657#else
3658 else if constexpr (is_same_v<_Tp, __ieee128>)
3659 return __u._M_f128;
3660 else if constexpr (is_same_v<_Tp, __ibm128>)
3661 return __u._M_ibm128;
3662#endif
3663 else if constexpr (is_same_v<_Tp, const _CharT*>)
3664 return __u._M_str;
3665 else if constexpr (is_same_v<_Tp, basic_string_view<_CharT>>)
3666 return __u._M_sv;
3667 else if constexpr (is_same_v<_Tp, const void*>)
3668 return __u._M_ptr;
3669#ifdef __SIZEOF_INT128__
3670 else if constexpr (is_same_v<_Tp, __int128>)
3671 return __u._M_i128;
3672 else if constexpr (is_same_v<_Tp, unsigned __int128>)
3673 return __u._M_u128;
3674#endif
3675#if _GLIBCXX_FORMAT_F128 == 2
3676 else if constexpr (is_same_v<_Tp, __float128_t>)
3677 return __u._M_f128;
3678#endif
3679 else if constexpr (derived_from<_Tp, _HandleBase>)
3680 return static_cast<_Tp&>(__u._M_handle);
3681 // Otherwise, ill-formed.
3682 }
3683
3684 template<typename _Tp>
3685 [[__gnu__::__always_inline__]]
3686 auto&
3687 _M_get() noexcept
3688 { return _S_get<_Tp>(*this); }
3689
3690 template<typename _Tp>
3691 [[__gnu__::__always_inline__]]
3692 const auto&
3693 _M_get() const noexcept
3694 { return _S_get<_Tp>(*this); }
3695
3696 template<typename _Tp>
3697 [[__gnu__::__always_inline__]]
3698 void
3699 _M_set(_Tp __v) noexcept
3700 {
3701 if constexpr (derived_from<_Tp, _HandleBase>)
3702 std::construct_at(&_M_handle, __v);
3703 else
3704 _S_get<_Tp>(*this) = __v;
3705 }
3706 };
3707
3708 // [format.arg.store], class template format-arg-store
3709 template<typename _Context, typename... _Args>
3710 class _Arg_store;
3711
3712 template<typename _Visitor, typename _Ctx>
3713 decltype(auto) __visit_format_arg(_Visitor&&, basic_format_arg<_Ctx>);
3714
3715 template<typename _Ch, typename _Tp>
3716 consteval _Arg_t
3717 __to_arg_t_enum() noexcept;
3718} // namespace __format
3719/// @endcond
3720
3721 template<typename _Context>
3722 class basic_format_arg
3723 {
3724 using _CharT = typename _Context::char_type;
3725
3726 template<typename _Tp>
3727 static constexpr bool __formattable
3728 = __format::__formattable_with<_Tp, _Context>;
3729
3730 public:
3731 class handle : public __format::_Arg_value<_Context>::_HandleBase
3732 {
3733 using _Base = typename __format::_Arg_value<_Context>::_HandleBase;
3734
3735 // Format as const if possible, to reduce instantiations.
3736 template<typename _Tp>
3737 using __maybe_const_t
3738 = __conditional_t<__formattable<const _Tp>, const _Tp, _Tp>;
3739
3740 template<typename _Tq>
3741 static void
3742 _S_format(basic_format_parse_context<_CharT>& __parse_ctx,
3743 _Context& __format_ctx, const void* __ptr)
3744 {
3745 using _Td = remove_const_t<_Tq>;
3746 typename _Context::template formatter_type<_Td> __f;
3747 __parse_ctx.advance_to(__f.parse(__parse_ctx));
3748 _Tq& __val = *const_cast<_Tq*>(static_cast<const _Td*>(__ptr));
3749 __format_ctx.advance_to(__f.format(__val, __format_ctx));
3750 }
3751
3752 template<typename _Tp>
3753 explicit
3754 handle(_Tp& __val) noexcept
3755 {
3756 this->_M_ptr = __builtin_addressof(__val);
3757 auto __func = _S_format<__maybe_const_t<_Tp>>;
3758 this->_M_func = reinterpret_cast<void(*)()>(__func);
3759 }
3760
3761 friend class basic_format_arg<_Context>;
3762
3763 public:
3764 handle(const handle&) = default;
3765 handle& operator=(const handle&) = default;
3766
3767 [[__gnu__::__always_inline__]]
3768 void
3769 format(basic_format_parse_context<_CharT>& __pc, _Context& __fc) const
3770 {
3771 using _Func = void(*)(basic_format_parse_context<_CharT>&,
3772 _Context&, const void*);
3773 auto __f = reinterpret_cast<_Func>(this->_M_func);
3774 __f(__pc, __fc, this->_M_ptr);
3775 }
3776 };
3777
3778 [[__gnu__::__always_inline__]]
3779 basic_format_arg() noexcept : _M_type(__format::_Arg_none) { }
3780
3781 [[nodiscard,__gnu__::__always_inline__]]
3782 explicit operator bool() const noexcept
3783 { return _M_type != __format::_Arg_none; }
3784
3785#if __cpp_lib_format >= 202306L // >= C++26
3786 template<typename _Visitor>
3787 decltype(auto)
3788 visit(this basic_format_arg __arg, _Visitor&& __vis)
3789 { return __arg._M_visit_user(std::forward<_Visitor>(__vis), __arg._M_type); }
3790
3791 template<typename _Res, typename _Visitor>
3792 _Res
3793 visit(this basic_format_arg __arg, _Visitor&& __vis)
3794 { return __arg._M_visit_user(std::forward<_Visitor>(__vis), __arg._M_type); }
3795#endif
3796
3797 private:
3798 template<typename _Ctx>
3799 friend class basic_format_args;
3800
3801 template<typename _Ctx, typename... _Args>
3802 friend class __format::_Arg_store;
3803
3804 static_assert(is_trivially_copyable_v<__format::_Arg_value<_Context>>);
3805
3806 __format::_Arg_value<_Context> _M_val;
3807 __format::_Arg_t _M_type;
3808
3809 // Transform incoming argument type to the type stored in _Arg_value.
3810 // e.g. short -> int, std::string -> std::string_view,
3811 // char[3] -> const char*.
3812 template<typename _Tp>
3813 static consteval auto
3814 _S_to_arg_type()
3815 {
3816 using _Td = remove_const_t<_Tp>;
3817 if constexpr (is_same_v<_Td, bool>)
3818 return type_identity<bool>();
3819 else if constexpr (is_same_v<_Td, _CharT>)
3820 return type_identity<_CharT>();
3821 else if constexpr (is_same_v<_Td, char> && is_same_v<_CharT, wchar_t>)
3822 return type_identity<_CharT>();
3823#ifdef __SIZEOF_INT128__ // Check before signed/unsigned integer
3824 else if constexpr (is_same_v<_Td, __int128>)
3825 return type_identity<__int128>();
3826 else if constexpr (is_same_v<_Td, unsigned __int128>)
3827 return type_identity<unsigned __int128>();
3828#endif
3829 else if constexpr (__is_signed_integer<_Td>::value)
3830 {
3831 if constexpr (sizeof(_Td) <= sizeof(int))
3832 return type_identity<int>();
3833 else if constexpr (sizeof(_Td) <= sizeof(long long))
3834 return type_identity<long long>();
3835 }
3836 else if constexpr (__is_unsigned_integer<_Td>::value)
3837 {
3838 if constexpr (sizeof(_Td) <= sizeof(unsigned))
3839 return type_identity<unsigned>();
3840 else if constexpr (sizeof(_Td) <= sizeof(unsigned long long))
3841 return type_identity<unsigned long long>();
3842 }
3843 else if constexpr (is_same_v<_Td, float>)
3844 return type_identity<float>();
3845 else if constexpr (is_same_v<_Td, double>)
3846 return type_identity<double>();
3847#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3848 else if constexpr (is_same_v<_Td, long double>)
3849 return type_identity<long double>();
3850#else
3851 else if constexpr (is_same_v<_Td, __ibm128>)
3852 return type_identity<__ibm128>();
3853 else if constexpr (is_same_v<_Td, __ieee128>)
3854 return type_identity<__ieee128>();
3855#endif
3856
3857#if defined(__FLT16_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
3858 else if constexpr (is_same_v<_Td, _Float16>)
3859 return type_identity<float>();
3860#endif
3861
3862#if defined(__BFLT16_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
3863 else if constexpr (is_same_v<_Td, decltype(0.0bf16)>)
3864 return type_identity<float>();
3865#endif
3866
3867#if defined(__FLT32_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
3868 else if constexpr (is_same_v<_Td, _Float32>)
3869 return type_identity<float>();
3870#endif
3871
3872#if defined(__FLT64_DIG__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
3873 else if constexpr (is_same_v<_Td, _Float64>)
3874 return type_identity<double>();
3875#endif
3876
3877#if _GLIBCXX_FORMAT_F128
3878# if __FLT128_DIG__
3879 else if constexpr (is_same_v<_Td, _Float128>)
3880 return type_identity<__format::__float128_t>();
3881# endif
3882# if __SIZEOF_FLOAT128__
3883 else if constexpr (is_same_v<_Td, __float128>)
3884 return type_identity<__format::__float128_t>();
3885# endif
3886#endif
3887 else if constexpr (__is_specialization_of<_Td, basic_string_view>
3888 || __is_specialization_of<_Td, basic_string>)
3889 {
3890 if constexpr (is_same_v<typename _Td::value_type, _CharT>)
3891 return type_identity<basic_string_view<_CharT>>();
3892 else
3893 return type_identity<handle>();
3894 }
3895 else if constexpr (is_same_v<decay_t<_Td>, const _CharT*>)
3896 return type_identity<const _CharT*>();
3897 else if constexpr (is_same_v<decay_t<_Td>, _CharT*>)
3898 return type_identity<const _CharT*>();
3899 else if constexpr (is_void_v<remove_pointer_t<_Td>>)
3900 return type_identity<const void*>();
3901 else if constexpr (is_same_v<_Td, nullptr_t>)
3902 return type_identity<const void*>();
3903 else
3904 return type_identity<handle>();
3905 }
3906
3907 // Transform a formattable type to the appropriate storage type.
3908 template<typename _Tp>
3909 using _Normalize = typename decltype(_S_to_arg_type<_Tp>())::type;
3910
3911 // Get the _Arg_t value corresponding to a normalized type.
3912 template<typename _Tp>
3913 static consteval __format::_Arg_t
3914 _S_to_enum()
3915 {
3916 using namespace __format;
3917 if constexpr (is_same_v<_Tp, bool>)
3918 return _Arg_bool;
3919 else if constexpr (is_same_v<_Tp, _CharT>)
3920 return _Arg_c;
3921 else if constexpr (is_same_v<_Tp, int>)
3922 return _Arg_i;
3923 else if constexpr (is_same_v<_Tp, unsigned>)
3924 return _Arg_u;
3925 else if constexpr (is_same_v<_Tp, long long>)
3926 return _Arg_ll;
3927 else if constexpr (is_same_v<_Tp, unsigned long long>)
3928 return _Arg_ull;
3929 else if constexpr (is_same_v<_Tp, float>)
3930 return _Arg_flt;
3931 else if constexpr (is_same_v<_Tp, double>)
3932 return _Arg_dbl;
3933#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3934 else if constexpr (is_same_v<_Tp, long double>)
3935 return _Arg_ldbl;
3936#else
3937 // Don't use _Arg_ldbl for this target, it's ambiguous.
3938 else if constexpr (is_same_v<_Tp, __ibm128>)
3939 return _Arg_ibm128;
3940 else if constexpr (is_same_v<_Tp, __ieee128>)
3941 return _Arg_f128;
3942#endif
3943 else if constexpr (is_same_v<_Tp, const _CharT*>)
3944 return _Arg_str;
3945 else if constexpr (is_same_v<_Tp, basic_string_view<_CharT>>)
3946 return _Arg_sv;
3947 else if constexpr (is_same_v<_Tp, const void*>)
3948 return _Arg_ptr;
3949#ifdef __SIZEOF_INT128__
3950 else if constexpr (is_same_v<_Tp, __int128>)
3951 return _Arg_i128;
3952 else if constexpr (is_same_v<_Tp, unsigned __int128>)
3953 return _Arg_u128;
3954#endif
3955
3956#if _GLIBCXX_FORMAT_F128 == 2
3957 else if constexpr (is_same_v<_Tp, __format::__float128_t>)
3958 return _Arg_f128;
3959#endif
3960 else if constexpr (is_same_v<_Tp, handle>)
3961 return _Arg_handle;
3962 }
3963
3964 template<typename _Tp>
3965 void
3966 _M_set(_Tp __v) noexcept
3967 {
3968 _M_type = _S_to_enum<_Tp>();
3969 _M_val._M_set(__v);
3970 }
3971
3972 template<typename _Tp>
3973 requires __format::__formattable_with<_Tp, _Context>
3974 explicit
3975 basic_format_arg(_Tp& __v) noexcept
3976 {
3977 using _Td = _Normalize<_Tp>;
3978 if constexpr (is_same_v<_Td, basic_string_view<_CharT>>)
3979 _M_set(_Td{__v.data(), __v.size()});
3980 else if constexpr (is_same_v<remove_const_t<_Tp>, char>
3981 && is_same_v<_CharT, wchar_t>)
3982 _M_set(static_cast<_Td>(static_cast<unsigned char>(__v)));
3983 else
3984 _M_set(static_cast<_Td>(__v));
3985 }
3986
3987 template<typename _Ctx, typename... _Argz>
3988 friend auto
3989 make_format_args(_Argz&...) noexcept;
3990
3991 template<typename _Visitor, typename _Ctx>
3992 friend decltype(auto)
3993 visit_format_arg(_Visitor&& __vis, basic_format_arg<_Ctx>);
3994
3995 template<typename _Visitor, typename _Ctx>
3996 friend decltype(auto)
3997 __format::__visit_format_arg(_Visitor&&, basic_format_arg<_Ctx>);
3998
3999 template<typename _Ch, typename _Tp>
4000 friend consteval __format::_Arg_t
4001 __format::__to_arg_t_enum() noexcept;
4002
4003 template<typename _Visitor>
4004 decltype(auto)
4005 _M_visit(_Visitor&& __vis, __format::_Arg_t __type)
4006 {
4007 using namespace __format;
4008 switch (__type)
4009 {
4010 case _Arg_none:
4011 return std::forward<_Visitor>(__vis)(_M_val._M_none);
4012 case _Arg_bool:
4013 return std::forward<_Visitor>(__vis)(_M_val._M_bool);
4014 case _Arg_c:
4015 return std::forward<_Visitor>(__vis)(_M_val._M_c);
4016 case _Arg_i:
4017 return std::forward<_Visitor>(__vis)(_M_val._M_i);
4018 case _Arg_u:
4019 return std::forward<_Visitor>(__vis)(_M_val._M_u);
4020 case _Arg_ll:
4021 return std::forward<_Visitor>(__vis)(_M_val._M_ll);
4022 case _Arg_ull:
4023 return std::forward<_Visitor>(__vis)(_M_val._M_ull);
4024#if __glibcxx_to_chars // FIXME: need to be able to format these types!
4025 case _Arg_flt:
4026 return std::forward<_Visitor>(__vis)(_M_val._M_flt);
4027 case _Arg_dbl:
4028 return std::forward<_Visitor>(__vis)(_M_val._M_dbl);
4029#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
4030 case _Arg_ldbl:
4031 return std::forward<_Visitor>(__vis)(_M_val._M_ldbl);
4032#else
4033 case _Arg_f128:
4034 return std::forward<_Visitor>(__vis)(_M_val._M_f128);
4035 case _Arg_ibm128:
4036 return std::forward<_Visitor>(__vis)(_M_val._M_ibm128);
4037#endif
4038#endif
4039 case _Arg_str:
4040 return std::forward<_Visitor>(__vis)(_M_val._M_str);
4041 case _Arg_sv:
4042 return std::forward<_Visitor>(__vis)(_M_val._M_sv);
4043 case _Arg_ptr:
4044 return std::forward<_Visitor>(__vis)(_M_val._M_ptr);
4045 case _Arg_handle:
4046 {
4047 auto& __h = static_cast<handle&>(_M_val._M_handle);
4048 return std::forward<_Visitor>(__vis)(__h);
4049 }
4050#ifdef __SIZEOF_INT128__
4051 case _Arg_i128:
4052 return std::forward<_Visitor>(__vis)(_M_val._M_i128);
4053 case _Arg_u128:
4054 return std::forward<_Visitor>(__vis)(_M_val._M_u128);
4055#endif
4056
4057#if _GLIBCXX_FORMAT_F128 == 2
4058 case _Arg_f128:
4059 return std::forward<_Visitor>(__vis)(_M_val._M_f128);
4060#endif
4061
4062 default:
4063 // _Arg_f16 etc.
4064 __builtin_unreachable();
4065 }
4066 }
4067
4068 template<typename _Visitor>
4069 decltype(auto)
4070 _M_visit_user(_Visitor&& __vis, __format::_Arg_t __type)
4071 {
4072 return _M_visit([&__vis]<typename _Tp>(_Tp& __val) -> decltype(auto)
4073 {
4074 constexpr bool __user_facing = __is_one_of<_Tp,
4075 monostate, bool, _CharT,
4076 int, unsigned int, long long int, unsigned long long int,
4077 float, double, long double,
4078 const _CharT*, basic_string_view<_CharT>,
4079 const void*, handle>::value;
4080 if constexpr (__user_facing)
4081 return std::forward<_Visitor>(__vis)(__val);
4082 else
4083 {
4084 handle __h(__val);
4085 return std::forward<_Visitor>(__vis)(__h);
4086 }
4087 }, __type);
4088 }
4089 };
4090
4091 template<typename _Visitor, typename _Context>
4092 _GLIBCXX26_DEPRECATED_SUGGEST("std::basic_format_arg::visit")
4093 inline decltype(auto)
4094 visit_format_arg(_Visitor&& __vis, basic_format_arg<_Context> __arg)
4095 {
4096 return __arg._M_visit_user(std::forward<_Visitor>(__vis), __arg._M_type);
4097 }
4098
4099/// @cond undocumented
4100namespace __format
4101{
4102 template<typename _Visitor, typename _Ctx>
4103 inline decltype(auto)
4104 __visit_format_arg(_Visitor&& __vis, basic_format_arg<_Ctx> __arg)
4105 {
4106 return __arg._M_visit(std::forward<_Visitor>(__vis), __arg._M_type);
4107 }
4108
4109 struct _WidthPrecVisitor
4110 {
4111 template<typename _Tp>
4112 size_t
4113 operator()(_Tp& __arg) const
4114 {
4115 if constexpr (is_same_v<_Tp, monostate>)
4116 __format::__invalid_arg_id_in_format_string();
4117 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4118 // 3720. Restrict the valid types of arg-id for width and precision
4119 // 3721. Allow an arg-id with a value of zero for width
4120 else if constexpr (sizeof(_Tp) <= sizeof(long long))
4121 {
4122 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4123 // 3720. Restrict the valid types of arg-id for width and precision
4124 if constexpr (__is_unsigned_integer<_Tp>::value)
4125 return __arg;
4126 else if constexpr (__is_signed_integer<_Tp>::value)
4127 if (__arg >= 0)
4128 return __arg;
4129 }
4130 __throw_format_error("format error: argument used for width or "
4131 "precision must be a non-negative integer");
4132 }
4133 };
4134
4135#pragma GCC diagnostic push
4136#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
4137 template<typename _Context>
4138 inline size_t
4139 __int_from_arg(const basic_format_arg<_Context>& __arg)
4140 { return __format::__visit_format_arg(_WidthPrecVisitor(), __arg); }
4141
4142 // Pack _Arg_t enum values into a single 60-bit integer.
4143 template<int _Bits, size_t _Nm>
4144 constexpr auto
4145 __pack_arg_types(const array<_Arg_t, _Nm>& __types)
4146 {
4147 __UINT64_TYPE__ __packed_types = 0;
4148 for (auto __i = __types.rbegin(); __i != __types.rend(); ++__i)
4149 __packed_types = (__packed_types << _Bits) | *__i;
4150 return __packed_types;
4151 }
4152} // namespace __format
4153/// @endcond
4154
4155 template<typename _Context>
4156 class basic_format_args
4157 {
4158 static constexpr int _S_packed_type_bits = 5; // _Arg_t values [0,20]
4159 static constexpr int _S_packed_type_mask = 0b11111;
4160 static constexpr int _S_max_packed_args = 12;
4161
4162 static_assert( __format::_Arg_max_ <= (1 << _S_packed_type_bits) );
4163
4164 template<typename... _Args>
4165 using _Store = __format::_Arg_store<_Context, _Args...>;
4166
4167 template<typename _Ctx, typename... _Args>
4168 friend class __format::_Arg_store;
4169
4170 using uint64_t = __UINT64_TYPE__;
4171 using _Format_arg = basic_format_arg<_Context>;
4172 using _Format_arg_val = __format::_Arg_value<_Context>;
4173
4174 // If args are packed then the number of args is in _M_packed_size and
4175 // the packed types are in _M_unpacked_size, accessed via _M_type(i).
4176 // If args are not packed then the number of args is in _M_unpacked_size
4177 // and _M_packed_size is zero.
4178 uint64_t _M_packed_size : 4;
4179 uint64_t _M_unpacked_size : 60;
4180
4181 union {
4182 const _Format_arg_val* _M_values; // Active when _M_packed_size != 0
4183 const _Format_arg* _M_args; // Active when _M_packed_size == 0
4184 };
4185
4186 size_t
4187 _M_size() const noexcept
4188 { return _M_packed_size ? _M_packed_size : _M_unpacked_size; }
4189
4190 typename __format::_Arg_t
4191 _M_type(size_t __i) const noexcept
4192 {
4193 uint64_t __t = _M_unpacked_size >> (__i * _S_packed_type_bits);
4194 return static_cast<__format::_Arg_t>(__t & _S_packed_type_mask);
4195 }
4196
4197 template<typename _Ctx, typename... _Args>
4198 friend auto
4199 make_format_args(_Args&...) noexcept;
4200
4201 // An array of _Arg_t enums corresponding to _Args...
4202 template<typename... _Args>
4203 static consteval array<__format::_Arg_t, sizeof...(_Args)>
4204 _S_types_to_pack()
4205 { return {_Format_arg::template _S_to_enum<_Args>()...}; }
4206
4207 public:
4208 template<typename... _Args>
4209 basic_format_args(const _Store<_Args...>& __store) noexcept;
4210
4211 [[nodiscard,__gnu__::__always_inline__]]
4212 basic_format_arg<_Context>
4213 get(size_t __i) const noexcept
4214 {
4215 basic_format_arg<_Context> __arg;
4216 if (__i < _M_packed_size)
4217 {
4218 __arg._M_type = _M_type(__i);
4219 __arg._M_val = _M_values[__i];
4220 }
4221 else if (_M_packed_size == 0 && __i < _M_unpacked_size)
4222 __arg = _M_args[__i];
4223 return __arg;
4224 }
4225 };
4226
4227 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4228 // 3810. CTAD for std::basic_format_args
4229 template<typename _Context, typename... _Args>
4230 basic_format_args(__format::_Arg_store<_Context, _Args...>)
4231 -> basic_format_args<_Context>;
4232
4233 template<typename _Context, typename... _Args>
4234 auto
4235 make_format_args(_Args&... __fmt_args) noexcept;
4236
4237 // An array of type-erased formatting arguments.
4238 template<typename _Context, typename... _Args>
4239 class __format::_Arg_store
4240 {
4241 friend std::basic_format_args<_Context>;
4242
4243 template<typename _Ctx, typename... _Argz>
4244 friend auto std::
4245#if _GLIBCXX_INLINE_VERSION
4246 __8:: // Needed for PR c++/59256
4247#endif
4248 make_format_args(_Argz&...) noexcept;
4249
4250 // For a sufficiently small number of arguments we only store values.
4251 // basic_format_args can get the types from the _Args pack.
4252 static constexpr bool _S_values_only
4253 = sizeof...(_Args) <= basic_format_args<_Context>::_S_max_packed_args;
4254
4255 using _Element_t
4256 = __conditional_t<_S_values_only,
4257 __format::_Arg_value<_Context>,
4258 basic_format_arg<_Context>>;
4259
4260 _Element_t _M_args[sizeof...(_Args)];
4261
4262 template<typename _Tp>
4263 static _Element_t
4264 _S_make_elt(_Tp& __v)
4265 {
4266 using _Tq = remove_const_t<_Tp>;
4267 using _CharT = typename _Context::char_type;
4268 static_assert(is_default_constructible_v<formatter<_Tq, _CharT>>,
4269 "std::formatter must be specialized for the type "
4270 "of each format arg");
4271 using __format::__formattable_with;
4272 if constexpr (is_const_v<_Tp>)
4273 if constexpr (!__formattable_with<_Tp, _Context>)
4274 if constexpr (__formattable_with<_Tq, _Context>)
4275 static_assert(__formattable_with<_Tp, _Context>,
4276 "format arg must be non-const because its "
4277 "std::formatter specialization has a "
4278 "non-const reference parameter");
4279 basic_format_arg<_Context> __arg(__v);
4280 if constexpr (_S_values_only)
4281 return __arg._M_val;
4282 else
4283 return __arg;
4284 }
4285
4286 template<typename... _Tp>
4287 requires (sizeof...(_Tp) == sizeof...(_Args))
4288 [[__gnu__::__always_inline__]]
4289 _Arg_store(_Tp&... __a) noexcept
4290 : _M_args{_S_make_elt(__a)...}
4291 { }
4292 };
4293
4294 template<typename _Context>
4295 class __format::_Arg_store<_Context>
4296 { };
4297
4298 template<typename _Context>
4299 template<typename... _Args>
4300 inline
4301 basic_format_args<_Context>::
4302 basic_format_args(const _Store<_Args...>& __store) noexcept
4303 {
4304 if constexpr (sizeof...(_Args) == 0)
4305 {
4306 _M_packed_size = 0;
4307 _M_unpacked_size = 0;
4308 _M_args = nullptr;
4309 }
4310 else if constexpr (sizeof...(_Args) <= _S_max_packed_args)
4311 {
4312 // The number of packed arguments:
4313 _M_packed_size = sizeof...(_Args);
4314 // The packed type enums:
4315 _M_unpacked_size
4316 = __format::__pack_arg_types<_S_packed_type_bits>(_S_types_to_pack<_Args...>());
4317 // The _Arg_value objects.
4318 _M_values = __store._M_args;
4319 }
4320 else
4321 {
4322 // No packed arguments:
4323 _M_packed_size = 0;
4324 // The number of unpacked arguments:
4325 _M_unpacked_size = sizeof...(_Args);
4326 // The basic_format_arg objects:
4327 _M_args = __store._M_args;
4328 }
4329 }
4330
4331 /// Capture formatting arguments for use by `std::vformat`.
4332 template<typename _Context = format_context, typename... _Args>
4333 [[nodiscard,__gnu__::__always_inline__]]
4334 inline auto
4335 make_format_args(_Args&... __fmt_args) noexcept
4336 {
4337 using _Fmt_arg = basic_format_arg<_Context>;
4338 using _Store = __format::_Arg_store<_Context, typename _Fmt_arg::template
4339 _Normalize<_Args>...>;
4340 return _Store(__fmt_args...);
4341 }
4342
4343#ifdef _GLIBCXX_USE_WCHAR_T
4344 /// Capture formatting arguments for use by `std::vformat` (for wide output).
4345 template<typename... _Args>
4346 [[nodiscard,__gnu__::__always_inline__]]
4347 inline auto
4348 make_wformat_args(_Args&... __args) noexcept
4349 { return std::make_format_args<wformat_context>(__args...); }
4350#endif
4351
4352/// @cond undocumented
4353namespace __format
4354{
4355 template<typename _Out, typename _CharT, typename _Context>
4356 _Out
4357 __do_vformat_to(_Out, basic_string_view<_CharT>,
4358 const basic_format_args<_Context>&,
4359 const locale* = nullptr);
4360
4361 template<typename _CharT> struct __formatter_chrono;
4362
4363} // namespace __format
4364/// @endcond
4365
4366 /** Context for std::format and similar functions.
4367 *
4368 * A formatting context contains an output iterator and locale to use
4369 * for the formatting operations. Most programs will never need to use
4370 * this class template explicitly. For typical uses of `std::format` the
4371 * library will use the specializations `std::format_context` (for `char`)
4372 * and `std::wformat_context` (for `wchar_t`).
4373 *
4374 * You are not allowed to define partial or explicit specializations of
4375 * this class template.
4376 *
4377 * @since C++20
4378 */
4379 template<typename _Out, typename _CharT>
4380 class basic_format_context
4381 {
4382 static_assert( output_iterator<_Out, const _CharT&> );
4383
4384 basic_format_args<basic_format_context> _M_args;
4385 _Out _M_out;
4386 __format::_Optional_locale _M_loc;
4387
4388 basic_format_context(basic_format_args<basic_format_context> __args,
4389 _Out __out)
4390 : _M_args(__args), _M_out(std::move(__out))
4391 { }
4392
4393 basic_format_context(basic_format_args<basic_format_context> __args,
4394 _Out __out, const std::locale& __loc)
4395 : _M_args(__args), _M_out(std::move(__out)), _M_loc(__loc)
4396 { }
4397
4398 // _GLIBCXX_RESOLVE_LIB_DEFECTS
4399 // 4061. Should std::basic_format_context be
4400 // default-constructible/copyable/movable?
4401 basic_format_context(const basic_format_context&) = delete;
4402 basic_format_context& operator=(const basic_format_context&) = delete;
4403
4404 template<typename _Out2, typename _CharT2, typename _Context2>
4405 friend _Out2
4406 __format::__do_vformat_to(_Out2, basic_string_view<_CharT2>,
4407 const basic_format_args<_Context2>&,
4408 const locale*);
4409
4410 friend __format::__formatter_chrono<_CharT>;
4411
4412 public:
4413 ~basic_format_context() = default;
4414
4415 using iterator = _Out;
4416 using char_type = _CharT;
4417 template<typename _Tp>
4418 using formatter_type = formatter<_Tp, _CharT>;
4419
4420 [[nodiscard]]
4421 basic_format_arg<basic_format_context>
4422 arg(size_t __id) const noexcept
4423 { return _M_args.get(__id); }
4424
4425 [[nodiscard]]
4426 std::locale locale() { return _M_loc.value(); }
4427
4428 [[nodiscard]]
4429 iterator out() { return std::move(_M_out); }
4430
4431 void advance_to(iterator __it) { _M_out = std::move(__it); }
4432 };
4433
4434
4435/// @cond undocumented
4436namespace __format
4437{
4438 // Abstract base class defining an interface for scanning format strings.
4439 // Scan the characters in a format string, dividing it up into strings of
4440 // ordinary characters, escape sequences, and replacement fields.
4441 // Call virtual functions for derived classes to parse format-specifiers
4442 // or write formatted output.
4443 template<typename _CharT>
4444 struct _Scanner
4445 {
4446 using iterator = typename basic_format_parse_context<_CharT>::iterator;
4447
4448 struct _Parse_context : basic_format_parse_context<_CharT>
4449 {
4450 using basic_format_parse_context<_CharT>::basic_format_parse_context;
4451 const _Arg_t* _M_types = nullptr;
4452 } _M_pc;
4453
4454 constexpr explicit
4455 _Scanner(basic_string_view<_CharT> __str, size_t __nargs = (size_t)-1)
4456 : _M_pc(__str, __nargs)
4457 { }
4458
4459 constexpr iterator begin() const noexcept { return _M_pc.begin(); }
4460 constexpr iterator end() const noexcept { return _M_pc.end(); }
4461
4462 constexpr void
4463 _M_scan()
4464 {
4465 basic_string_view<_CharT> __fmt = _M_fmt_str();
4466
4467 if (__fmt.size() == 2 && __fmt[0] == '{' && __fmt[1] == '}')
4468 {
4469 _M_pc.advance_to(begin() + 1);
4470 _M_format_arg(_M_pc.next_arg_id());
4471 return;
4472 }
4473
4474 size_t __lbr = __fmt.find('{');
4475 size_t __rbr = __fmt.find('}');
4476
4477 while (__fmt.size())
4478 {
4479 auto __cmp = __lbr <=> __rbr;
4480 if (__cmp == 0)
4481 {
4482 _M_on_chars(end());
4483 _M_pc.advance_to(end());
4484 return;
4485 }
4486 else if (__cmp < 0)
4487 {
4488 if (__lbr + 1 == __fmt.size()
4489 || (__rbr == __fmt.npos && __fmt[__lbr + 1] != '{'))
4490 __format::__unmatched_left_brace_in_format_string();
4491 const bool __is_escape = __fmt[__lbr + 1] == '{';
4492 iterator __last = begin() + __lbr + int(__is_escape);
4493 _M_on_chars(__last);
4494 _M_pc.advance_to(__last + 1);
4495 __fmt = _M_fmt_str();
4496 if (__is_escape)
4497 {
4498 if (__rbr != __fmt.npos)
4499 __rbr -= __lbr + 2;
4500 __lbr = __fmt.find('{');
4501 }
4502 else
4503 {
4504 _M_on_replacement_field();
4505 __fmt = _M_fmt_str();
4506 __lbr = __fmt.find('{');
4507 __rbr = __fmt.find('}');
4508 }
4509 }
4510 else
4511 {
4512 if (++__rbr == __fmt.size() || __fmt[__rbr] != '}')
4513 __format::__unmatched_right_brace_in_format_string();
4514 iterator __last = begin() + __rbr;
4515 _M_on_chars(__last);
4516 _M_pc.advance_to(__last + 1);
4517 __fmt = _M_fmt_str();
4518 if (__lbr != __fmt.npos)
4519 __lbr -= __rbr + 1;
4520 __rbr = __fmt.find('}');
4521 }
4522 }
4523 }
4524
4525 constexpr basic_string_view<_CharT>
4526 _M_fmt_str() const noexcept
4527 { return {begin(), end()}; }
4528
4529 constexpr virtual void _M_on_chars(iterator) { }
4530
4531 constexpr void _M_on_replacement_field()
4532 {
4533 auto __next = begin();
4534
4535 size_t __id;
4536 if (*__next == '}')
4537 __id = _M_pc.next_arg_id();
4538 else if (*__next == ':')
4539 {
4540 __id = _M_pc.next_arg_id();
4541 _M_pc.advance_to(++__next);
4542 }
4543 else
4544 {
4545 auto [__i, __ptr] = __format::__parse_arg_id(begin(), end());
4546 if (!__ptr || !(*__ptr == '}' || *__ptr == ':'))
4547 __format::__invalid_arg_id_in_format_string();
4548 _M_pc.check_arg_id(__id = __i);
4549 if (*__ptr == ':')
4550 {
4551 _M_pc.advance_to(++__ptr);
4552 }
4553 else
4554 _M_pc.advance_to(__ptr);
4555 }
4556 _M_format_arg(__id);
4557 if (begin() == end() || *begin() != '}')
4558 __format::__unmatched_left_brace_in_format_string();
4559 _M_pc.advance_to(begin() + 1); // Move past '}'
4560 }
4561
4562 constexpr virtual void _M_format_arg(size_t __id) = 0;
4563 };
4564
4565 // Process a format string and format the arguments in the context.
4566 template<typename _Out, typename _CharT>
4567 class _Formatting_scanner : public _Scanner<_CharT>
4568 {
4569 public:
4570 _Formatting_scanner(basic_format_context<_Out, _CharT>& __fc,
4571 basic_string_view<_CharT> __str)
4572 : _Scanner<_CharT>(__str), _M_fc(__fc)
4573 { }
4574
4575 private:
4576 basic_format_context<_Out, _CharT>& _M_fc;
4577
4578 using iterator = typename _Scanner<_CharT>::iterator;
4579
4580 constexpr void
4581 _M_on_chars(iterator __last) override
4582 {
4583 basic_string_view<_CharT> __str(this->begin(), __last);
4584 _M_fc.advance_to(__format::__write(_M_fc.out(), __str));
4585 }
4586
4587 constexpr void
4588 _M_format_arg(size_t __id) override
4589 {
4590 using _Context = basic_format_context<_Out, _CharT>;
4591 using handle = typename basic_format_arg<_Context>::handle;
4592
4593 __format::__visit_format_arg([this](auto& __arg) {
4594 using _Type = remove_reference_t<decltype(__arg)>;
4595 using _Formatter = typename _Context::template formatter_type<_Type>;
4596 if constexpr (is_same_v<_Type, monostate>)
4597 __format::__invalid_arg_id_in_format_string();
4598 else if constexpr (is_same_v<_Type, handle>)
4599 __arg.format(this->_M_pc, this->_M_fc);
4600 else if constexpr (is_default_constructible_v<_Formatter>)
4601 {
4602 _Formatter __f;
4603 this->_M_pc.advance_to(__f.parse(this->_M_pc));
4604 this->_M_fc.advance_to(__f.format(__arg, this->_M_fc));
4605 }
4606 else
4607 static_assert(__format::__formattable_with<_Type, _Context>);
4608 }, _M_fc.arg(__id));
4609 }
4610 };
4611
4612 template<typename _CharT, typename _Tp>
4613 consteval _Arg_t
4614 __to_arg_t_enum() noexcept
4615 {
4616 using _Context = __format::__format_context<_CharT>;
4617 using _Fmt_arg = basic_format_arg<_Context>;
4618 using _NormalizedTp = typename _Fmt_arg::template _Normalize<_Tp>;
4619 return _Fmt_arg::template _S_to_enum<_NormalizedTp>();
4620 }
4621
4622 // Validate a format string for Args.
4623 template<typename _CharT, typename... _Args>
4624 class _Checking_scanner : public _Scanner<_CharT>
4625 {
4626 static_assert(
4627 (is_default_constructible_v<formatter<_Args, _CharT>> && ...),
4628 "std::formatter must be specialized for each type being formatted");
4629
4630 public:
4631 consteval
4632 _Checking_scanner(basic_string_view<_CharT> __str)
4633 : _Scanner<_CharT>(__str, sizeof...(_Args))
4634 {
4635#if __cpp_lib_format >= 202305L
4636 this->_M_pc._M_types = _M_types.data();
4637#endif
4638 }
4639
4640 private:
4641 constexpr void
4642 _M_format_arg(size_t __id) override
4643 {
4644 if constexpr (sizeof...(_Args) != 0)
4645 {
4646 if (__id < sizeof...(_Args))
4647 {
4648 _M_parse_format_spec<_Args...>(__id);
4649 return;
4650 }
4651 }
4652 __builtin_unreachable();
4653 }
4654
4655 template<typename _Tp, typename... _OtherArgs>
4656 constexpr void
4657 _M_parse_format_spec(size_t __id)
4658 {
4659 if (__id == 0)
4660 {
4661 formatter<_Tp, _CharT> __f;
4662 this->_M_pc.advance_to(__f.parse(this->_M_pc));
4663 }
4664 else if constexpr (sizeof...(_OtherArgs) != 0)
4665 _M_parse_format_spec<_OtherArgs...>(__id - 1);
4666 else
4667 __builtin_unreachable();
4668 }
4669
4670#if __cpp_lib_format >= 202305L
4671 array<_Arg_t, sizeof...(_Args)>
4672 _M_types{ { __format::__to_arg_t_enum<_CharT, _Args>()... } };
4673#endif
4674 };
4675
4676 template<typename _Out, typename _CharT, typename _Context>
4677 inline _Out
4678 __do_vformat_to(_Out __out, basic_string_view<_CharT> __fmt,
4679 const basic_format_args<_Context>& __args,
4680 const locale* __loc)
4681 {
4682 _Iter_sink<_CharT, _Out> __sink(std::move(__out));
4683 _Sink_iter<_CharT> __sink_out;
4684
4685 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
4686 __sink_out = __out; // Already a sink iterator, safe to use post-move.
4687 else
4688 __sink_out = __sink.out();
4689
4690 if constexpr (is_same_v<_CharT, char>)
4691 // Fast path for "{}" format strings and simple format arg types.
4692 if (__fmt.size() == 2 && __fmt[0] == '{' && __fmt[1] == '}')
4693 {
4694 bool __done = false;
4695 __format::__visit_format_arg([&](auto& __arg) {
4696 using _Tp = remove_cvref_t<decltype(__arg)>;
4697 if constexpr (is_same_v<_Tp, bool>)
4698 {
4699 size_t __len = 4 + !__arg;
4700 const char* __chars[] = { "false", "true" };
4701 if (auto __res = __sink_out._M_reserve(__len))
4702 {
4703 __builtin_memcpy(__res.get(), __chars[__arg], __len);
4704 __res._M_bump(__len);
4705 __done = true;
4706 }
4707 }
4708 else if constexpr (is_same_v<_Tp, char>)
4709 {
4710 if (auto __res = __sink_out._M_reserve(1))
4711 {
4712 *__res.get() = __arg;
4713 __res._M_bump(1);
4714 __done = true;
4715 }
4716 }
4717 else if constexpr (is_integral_v<_Tp>)
4718 {
4719 make_unsigned_t<_Tp> __uval;
4720 const bool __neg = __arg < 0;
4721 if (__neg)
4722 __uval = make_unsigned_t<_Tp>(~__arg) + 1u;
4723 else
4724 __uval = __arg;
4725 const auto __n = __detail::__to_chars_len(__uval);
4726 if (auto __res = __sink_out._M_reserve(__n + __neg))
4727 {
4728 auto __ptr = __res.get();
4729 *__ptr = '-';
4730 __detail::__to_chars_10_impl(__ptr + (int)__neg, __n,
4731 __uval);
4732 __res._M_bump(__n + __neg);
4733 __done = true;
4734 }
4735 }
4736 else if constexpr (is_convertible_v<_Tp, string_view>)
4737 {
4738 string_view __sv = __arg;
4739 if (auto __res = __sink_out._M_reserve(__sv.size()))
4740 {
4741 __builtin_memcpy(__res.get(), __sv.data(), __sv.size());
4742 __res._M_bump(__sv.size());
4743 __done = true;
4744 }
4745 }
4746 }, __args.get(0));
4747
4748 if (__done)
4749 {
4750 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
4751 return __sink_out;
4752 else
4753 return std::move(__sink)._M_finish().out;
4754 }
4755 }
4756
4757 auto __ctx = __loc == nullptr
4758 ? _Context(__args, __sink_out)
4759 : _Context(__args, __sink_out, *__loc);
4760 _Formatting_scanner<_Sink_iter<_CharT>, _CharT> __scanner(__ctx, __fmt);
4761 __scanner._M_scan();
4762
4763 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
4764 return __ctx.out();
4765 else
4766 return std::move(__sink)._M_finish().out;
4767 }
4768#pragma GCC diagnostic pop
4769
4770} // namespace __format
4771/// @endcond
4772
4773#if __cpp_lib_format >= 202305L // >= C++26
4774 /// @cond undocumented
4775 // Common implementation of check_dynamic_spec{,_string,_integral}
4776 template<typename _CharT>
4777 template<typename... _Ts>
4778 consteval void
4779 basic_format_parse_context<_CharT>::
4780 __check_dynamic_spec(size_t __id) noexcept
4781 {
4782 if (__id >= _M_num_args)
4783 __format::__invalid_arg_id_in_format_string();
4784 if constexpr (sizeof...(_Ts) != 0)
4785 {
4786 using _Parse_ctx = __format::_Scanner<_CharT>::_Parse_context;
4787 auto __arg = static_cast<_Parse_ctx*>(this)->_M_types[__id];
4788 __format::_Arg_t __types[] = {
4789 __format::__to_arg_t_enum<_CharT, _Ts>()...
4790 };
4791 for (auto __t : __types)
4792 if (__arg == __t)
4793 return;
4794 }
4795 __invalid_dynamic_spec("arg(id) type does not match");
4796 }
4797 /// @endcond
4798#endif
4799
4800 template<typename _CharT, typename... _Args>
4801 template<typename _Tp>
4802 requires convertible_to<const _Tp&, basic_string_view<_CharT>>
4803 consteval
4804 basic_format_string<_CharT, _Args...>::
4805 basic_format_string(const _Tp& __s)
4806 : _M_str(__s)
4807 {
4808 __format::_Checking_scanner<_CharT, remove_cvref_t<_Args>...>
4809 __scanner(_M_str);
4810 __scanner._M_scan();
4811 }
4812
4813 // [format.functions], formatting functions
4814
4815 template<typename _Out> requires output_iterator<_Out, const char&>
4816 [[__gnu__::__always_inline__]]
4817 inline _Out
4818 vformat_to(_Out __out, string_view __fmt, format_args __args)
4819 { return __format::__do_vformat_to(std::move(__out), __fmt, __args); }
4820
4821#ifdef _GLIBCXX_USE_WCHAR_T
4822 template<typename _Out> requires output_iterator<_Out, const wchar_t&>
4823 [[__gnu__::__always_inline__]]
4824 inline _Out
4825 vformat_to(_Out __out, wstring_view __fmt, wformat_args __args)
4826 { return __format::__do_vformat_to(std::move(__out), __fmt, __args); }
4827#endif
4828
4829 template<typename _Out> requires output_iterator<_Out, const char&>
4830 [[__gnu__::__always_inline__]]
4831 inline _Out
4832 vformat_to(_Out __out, const locale& __loc, string_view __fmt,
4833 format_args __args)
4834 {
4835 return __format::__do_vformat_to(std::move(__out), __fmt, __args, &__loc);
4836 }
4837
4838#ifdef _GLIBCXX_USE_WCHAR_T
4839 template<typename _Out> requires output_iterator<_Out, const wchar_t&>
4840 [[__gnu__::__always_inline__]]
4841 inline _Out
4842 vformat_to(_Out __out, const locale& __loc, wstring_view __fmt,
4843 wformat_args __args)
4844 {
4845 return __format::__do_vformat_to(std::move(__out), __fmt, __args, &__loc);
4846 }
4847#endif
4848
4849 [[nodiscard]]
4850 inline string
4851 vformat(string_view __fmt, format_args __args)
4852 {
4853 __format::_Str_sink<char> __buf;
4854 std::vformat_to(__buf.out(), __fmt, __args);
4855 return std::move(__buf).get();
4856 }
4857
4858#ifdef _GLIBCXX_USE_WCHAR_T
4859 [[nodiscard]]
4860 inline wstring
4861 vformat(wstring_view __fmt, wformat_args __args)
4862 {
4863 __format::_Str_sink<wchar_t> __buf;
4864 std::vformat_to(__buf.out(), __fmt, __args);
4865 return std::move(__buf).get();
4866 }
4867#endif
4868
4869 [[nodiscard]]
4870 inline string
4871 vformat(const locale& __loc, string_view __fmt, format_args __args)
4872 {
4873 __format::_Str_sink<char> __buf;
4874 std::vformat_to(__buf.out(), __loc, __fmt, __args);
4875 return std::move(__buf).get();
4876 }
4877
4878#ifdef _GLIBCXX_USE_WCHAR_T
4879 [[nodiscard]]
4880 inline wstring
4881 vformat(const locale& __loc, wstring_view __fmt, wformat_args __args)
4882 {
4883 __format::_Str_sink<wchar_t> __buf;
4884 std::vformat_to(__buf.out(), __loc, __fmt, __args);
4885 return std::move(__buf).get();
4886 }
4887#endif
4888
4889 template<typename... _Args>
4890 [[nodiscard]]
4891 inline string
4892 format(format_string<_Args...> __fmt, _Args&&... __args)
4893 { return std::vformat(__fmt.get(), std::make_format_args(__args...)); }
4894
4895#ifdef _GLIBCXX_USE_WCHAR_T
4896 template<typename... _Args>
4897 [[nodiscard]]
4898 inline wstring
4899 format(wformat_string<_Args...> __fmt, _Args&&... __args)
4900 { return std::vformat(__fmt.get(), std::make_wformat_args(__args...)); }
4901#endif
4902
4903 template<typename... _Args>
4904 [[nodiscard]]
4905 inline string
4906 format(const locale& __loc, format_string<_Args...> __fmt,
4907 _Args&&... __args)
4908 {
4909 return std::vformat(__loc, __fmt.get(),
4910 std::make_format_args(__args...));
4911 }
4912
4913#ifdef _GLIBCXX_USE_WCHAR_T
4914 template<typename... _Args>
4915 [[nodiscard]]
4916 inline wstring
4917 format(const locale& __loc, wformat_string<_Args...> __fmt,
4918 _Args&&... __args)
4919 {
4920 return std::vformat(__loc, __fmt.get(),
4921 std::make_wformat_args(__args...));
4922 }
4923#endif
4924
4925 template<typename _Out, typename... _Args>
4926 requires output_iterator<_Out, const char&>
4927 inline _Out
4928 format_to(_Out __out, format_string<_Args...> __fmt, _Args&&... __args)
4929 {
4930 return std::vformat_to(std::move(__out), __fmt.get(),
4931 std::make_format_args(__args...));
4932 }
4933
4934#ifdef _GLIBCXX_USE_WCHAR_T
4935 template<typename _Out, typename... _Args>
4936 requires output_iterator<_Out, const wchar_t&>
4937 inline _Out
4938 format_to(_Out __out, wformat_string<_Args...> __fmt, _Args&&... __args)
4939 {
4940 return std::vformat_to(std::move(__out), __fmt.get(),
4941 std::make_wformat_args(__args...));
4942 }
4943#endif
4944
4945 template<typename _Out, typename... _Args>
4946 requires output_iterator<_Out, const char&>
4947 inline _Out
4948 format_to(_Out __out, const locale& __loc, format_string<_Args...> __fmt,
4949 _Args&&... __args)
4950 {
4951 return std::vformat_to(std::move(__out), __loc, __fmt.get(),
4952 std::make_format_args(__args...));
4953 }
4954
4955#ifdef _GLIBCXX_USE_WCHAR_T
4956 template<typename _Out, typename... _Args>
4957 requires output_iterator<_Out, const wchar_t&>
4958 inline _Out
4959 format_to(_Out __out, const locale& __loc, wformat_string<_Args...> __fmt,
4960 _Args&&... __args)
4961 {
4962 return std::vformat_to(std::move(__out), __loc, __fmt.get(),
4963 std::make_wformat_args(__args...));
4964 }
4965#endif
4966
4967 template<typename _Out, typename... _Args>
4968 requires output_iterator<_Out, const char&>
4969 inline format_to_n_result<_Out>
4970 format_to_n(_Out __out, iter_difference_t<_Out> __n,
4971 format_string<_Args...> __fmt, _Args&&... __args)
4972 {
4973 __format::_Iter_sink<char, _Out> __sink(std::move(__out), __n);
4974 std::vformat_to(__sink.out(), __fmt.get(),
4975 std::make_format_args(__args...));
4976 return std::move(__sink)._M_finish();
4977 }
4978
4979#ifdef _GLIBCXX_USE_WCHAR_T
4980 template<typename _Out, typename... _Args>
4981 requires output_iterator<_Out, const wchar_t&>
4982 inline format_to_n_result<_Out>
4983 format_to_n(_Out __out, iter_difference_t<_Out> __n,
4984 wformat_string<_Args...> __fmt, _Args&&... __args)
4985 {
4986 __format::_Iter_sink<wchar_t, _Out> __sink(std::move(__out), __n);
4987 std::vformat_to(__sink.out(), __fmt.get(),
4988 std::make_wformat_args(__args...));
4989 return std::move(__sink)._M_finish();
4990 }
4991#endif
4992
4993 template<typename _Out, typename... _Args>
4994 requires output_iterator<_Out, const char&>
4995 inline format_to_n_result<_Out>
4996 format_to_n(_Out __out, iter_difference_t<_Out> __n, const locale& __loc,
4997 format_string<_Args...> __fmt, _Args&&... __args)
4998 {
4999 __format::_Iter_sink<char, _Out> __sink(std::move(__out), __n);
5000 std::vformat_to(__sink.out(), __loc, __fmt.get(),
5001 std::make_format_args(__args...));
5002 return std::move(__sink)._M_finish();
5003 }
5004
5005#ifdef _GLIBCXX_USE_WCHAR_T
5006 template<typename _Out, typename... _Args>
5007 requires output_iterator<_Out, const wchar_t&>
5008 inline format_to_n_result<_Out>
5009 format_to_n(_Out __out, iter_difference_t<_Out> __n, const locale& __loc,
5010 wformat_string<_Args...> __fmt, _Args&&... __args)
5011 {
5012 __format::_Iter_sink<wchar_t, _Out> __sink(std::move(__out), __n);
5013 std::vformat_to(__sink.out(), __loc, __fmt.get(),
5014 std::make_wformat_args(__args...));
5015 return std::move(__sink)._M_finish();
5016 }
5017#endif
5018
5019/// @cond undocumented
5020namespace __format
5021{
5022#if 1
5023 template<typename _CharT>
5024 class _Counting_sink final : public _Iter_sink<_CharT, _CharT*>
5025 {
5026 public:
5027 _Counting_sink() : _Iter_sink<_CharT, _CharT*>(nullptr, 0) { }
5028
5029 [[__gnu__::__always_inline__]]
5030 size_t
5031 count() const
5032 { return this->_M_count + this->_M_used().size(); }
5033 };
5034#else
5035 template<typename _CharT>
5036 class _Counting_sink : public _Buf_sink<_CharT>
5037 {
5038 size_t _M_count = 0;
5039
5040 void
5041 _M_overflow() override
5042 {
5043 if (!std::is_constant_evaluated())
5044 _M_count += this->_M_used().size();
5045 this->_M_rewind();
5046 }
5047
5048 public:
5049 _Counting_sink() = default;
5050
5051 [[__gnu__::__always_inline__]]
5052 size_t
5053 count() noexcept
5054 {
5055 _Counting_sink::_M_overflow();
5056 return _M_count;
5057 }
5058 };
5059#endif
5060} // namespace __format
5061/// @endcond
5062
5063 template<typename... _Args>
5064 [[nodiscard]]
5065 inline size_t
5066 formatted_size(format_string<_Args...> __fmt, _Args&&... __args)
5067 {
5068 __format::_Counting_sink<char> __buf;
5069 std::vformat_to(__buf.out(), __fmt.get(),
5070 std::make_format_args(__args...));
5071 return __buf.count();
5072 }
5073
5074#ifdef _GLIBCXX_USE_WCHAR_T
5075 template<typename... _Args>
5076 [[nodiscard]]
5077 inline size_t
5078 formatted_size(wformat_string<_Args...> __fmt, _Args&&... __args)
5079 {
5080 __format::_Counting_sink<wchar_t> __buf;
5081 std::vformat_to(__buf.out(), __fmt.get(),
5082 std::make_wformat_args(__args...));
5083 return __buf.count();
5084 }
5085#endif
5086
5087 template<typename... _Args>
5088 [[nodiscard]]
5089 inline size_t
5090 formatted_size(const locale& __loc, format_string<_Args...> __fmt,
5091 _Args&&... __args)
5092 {
5093 __format::_Counting_sink<char> __buf;
5094 std::vformat_to(__buf.out(), __loc, __fmt.get(),
5095 std::make_format_args(__args...));
5096 return __buf.count();
5097 }
5098
5099#ifdef _GLIBCXX_USE_WCHAR_T
5100 template<typename... _Args>
5101 [[nodiscard]]
5102 inline size_t
5103 formatted_size(const locale& __loc, wformat_string<_Args...> __fmt,
5104 _Args&&... __args)
5105 {
5106 __format::_Counting_sink<wchar_t> __buf;
5107 std::vformat_to(__buf.out(), __loc, __fmt.get(),
5108 std::make_wformat_args(__args...));
5109 return __buf.count();
5110 }
5111#endif
5112
5113#if __glibcxx_format_ranges // C++ >= 23 && HOSTED
5114 // [format.range], formatting of ranges
5115 // [format.range.fmtkind], variable template format_kind
5116 enum class range_format {
5117 disabled,
5118 map,
5119 set,
5120 sequence,
5121 string,
5122 debug_string
5123 };
5124
5125 /** @brief A constant determining how a range should be formatted.
5126 *
5127 * The primary template of `std::format_kind` cannot be instantiated.
5128 * There is a partial specialization for input ranges and you can
5129 * specialize the variable template for your own cv-unqualified types
5130 * that satisfy the `ranges::input_range` concept.
5131 *
5132 * @since C++23
5133 */
5134 template<typename _Rg>
5135 constexpr auto format_kind = []{
5136 static_assert(false, "cannot use primary template of 'std::format_kind'");
5137 return type_identity<_Rg>{};
5138 }();
5139
5140 /// @cond undocumented
5141 template<typename _Tp>
5142 consteval range_format
5143 __fmt_kind()
5144 {
5145 using _Ref = ranges::range_reference_t<_Tp>;
5146 if constexpr (is_same_v<remove_cvref_t<_Ref>, _Tp>)
5147 return range_format::disabled;
5148 else if constexpr (requires { typename _Tp::key_type; })
5149 {
5150 if constexpr (requires { typename _Tp::mapped_type; })
5151 {
5152 using _Up = remove_cvref_t<_Ref>;
5153 if constexpr (__is_pair<_Up>)
5154 return range_format::map;
5155 else if constexpr (__is_specialization_of<_Up, tuple>)
5156 if constexpr (tuple_size_v<_Up> == 2)
5157 return range_format::map;
5158 }
5159 return range_format::set;
5160 }
5161 else
5162 return range_format::sequence;
5163 }
5164 /// @endcond
5165
5166 /// A constant determining how a range should be formatted.
5167 template<ranges::input_range _Rg> requires same_as<_Rg, remove_cvref_t<_Rg>>
5168 constexpr range_format format_kind<_Rg> = __fmt_kind<_Rg>();
5169
5170/// @cond undocumented
5171namespace __format
5172{
5173 template<typename _CharT, typename _Out, typename _Callback>
5174 typename basic_format_context<_Out, _CharT>::iterator
5175 __format_padded(basic_format_context<_Out, _CharT>& __fc,
5176 const _Spec<_CharT>& __spec,
5177 _Callback&& __call)
5178 {
5179 // This is required to implement formatting with padding,
5180 // as we need to format to temporary buffer, using the same iterator.
5181 static_assert(is_same_v<_Out, __format::_Sink_iter<_CharT>>);
5182
5183 if (__spec._M_get_width(__fc) == 0)
5184 return __call(__fc);
5185
5186 struct _Restore_out
5187 {
5188 _Restore_out(basic_format_context<_Sink_iter<_CharT>, _CharT>& __fc)
5189 : _M_ctx(std::addressof(__fc)), _M_out(__fc.out())
5190 { }
5191
5192 void _M_trigger()
5193 {
5194 if (_M_ctx)
5195 _M_ctx->advance_to(_M_out);
5196 _M_ctx = nullptr;
5197 }
5198
5199 ~_Restore_out()
5200 { _M_trigger(); }
5201
5202 private:
5203 basic_format_context<_Sink_iter<_CharT>, _CharT>* _M_ctx;
5204 _Sink_iter<_CharT> _M_out;
5205 };
5206
5207 _Restore_out __restore(__fc);
5208 // TODO Consider double sinking, first buffer of width
5209 // size and then original sink, if first buffer is overun
5210 // we do not need to align
5211 _Str_sink<_CharT> __buf;
5212 __fc.advance_to(__buf.out());
5213 __call(__fc);
5214 __restore._M_trigger();
5215
5216 basic_string_view<_CharT> __str(__buf.view());
5217 size_t __width;
5218 if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
5219 __width = __unicode::__field_width(__str);
5220 else
5221 __width = __str.size();
5222
5223 return __format::__write_padded_as_spec(__str, __width, __fc, __spec);
5224 }
5225
5226 // _Rg& and const _Rg& are both formattable and use same formatter
5227 // specialization for their references.
5228 template<typename _Rg, typename _CharT>
5229 concept __simply_formattable_range
5230 = __const_formattable_range<_Rg, _CharT>
5231 && same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>,
5232 remove_cvref_t<ranges::range_reference_t<const _Rg>>>;
5233
5234 template<size_t _Pos, typename _Tp, typename _CharT>
5235 struct __indexed_formatter_storage
5236 {
5237 constexpr void
5238 _M_parse()
5239 {
5240 basic_format_parse_context<_CharT> __pc({});
5241 if (_M_formatter.parse(__pc) != __pc.end())
5242 __format::__failed_to_parse_format_spec();
5243 }
5244
5245 template<typename _Out>
5246 void
5247 _M_format(__maybe_const<_Tp, _CharT>& __elem,
5248 basic_format_context<_Out, _CharT>& __fc,
5249 basic_string_view<_CharT> __sep) const
5250 {
5251 if constexpr (_Pos != 0)
5252 __fc.advance_to(__format::__write(__fc.out(), __sep));
5253 __fc.advance_to(_M_formatter.format(__elem, __fc));
5254 }
5255
5256 [[__gnu__::__always_inline__]]
5257 constexpr void
5258 set_debug_format()
5259 {
5260 if constexpr (__has_debug_format<formatter<_Tp, _CharT>>)
5261 _M_formatter.set_debug_format();
5262 }
5263
5264 private:
5265 formatter<_Tp, _CharT> _M_formatter;
5266 };
5267
5268 template<typename _CharT, typename... _Tps>
5269 class __tuple_formatter
5270 {
5271 using _String_view = basic_string_view<_CharT>;
5272 using _Seps = __format::_Separators<_CharT>;
5273
5274 public:
5275 constexpr void
5276 set_separator(basic_string_view<_CharT> __sep) noexcept
5277 { _M_sep = __sep; }
5278
5279 constexpr void
5280 set_brackets(basic_string_view<_CharT> __open,
5281 basic_string_view<_CharT> __close) noexcept
5282 {
5283 _M_open = __open;
5284 _M_close = __close;
5285 }
5286
5287 // We deviate from standard, that declares this as template accepting
5288 // unconstrained ParseContext type, which seems unimplementable.
5289 constexpr typename basic_format_parse_context<_CharT>::iterator
5290 parse(basic_format_parse_context<_CharT>& __pc)
5291 {
5292 auto __first = __pc.begin();
5293 const auto __last = __pc.end();
5294 __format::_Spec<_CharT> __spec{};
5295
5296 auto __finished = [&]
5297 {
5298 if (__first != __last && *__first != '}')
5299 return false;
5300
5301 _M_spec = __spec;
5302 _M_felems._M_parse();
5303 _M_felems.set_debug_format();
5304 return true;
5305 };
5306
5307 if (__finished())
5308 return __first;
5309
5310 __first = __spec._M_parse_fill_and_align(__first, __last, "{:");
5311 if (__finished())
5312 return __first;
5313
5314 __first = __spec._M_parse_width(__first, __last, __pc);
5315 if (__finished())
5316 return __first;
5317
5318 if (*__first == 'n')
5319 {
5320 ++__first;
5321 _M_open = _M_close = _String_view();
5322 }
5323 else if (*__first == 'm')
5324 {
5325 ++__first;
5326 if constexpr (sizeof...(_Tps) == 2)
5327 {
5328 _M_sep = _Seps::_S_colon();
5329 _M_open = _M_close = _String_view();
5330 }
5331 else
5332 __throw_format_error("format error: 'm' specifier requires range"
5333 " of pair or tuple of two elements");
5334 }
5335
5336 if (__finished())
5337 return __first;
5338
5339 __format::__failed_to_parse_format_spec();
5340 }
5341
5342 protected:
5343 template<typename _Tuple, typename _Out, size_t... _Ids>
5344 typename basic_format_context<_Out, _CharT>::iterator
5345 _M_format(_Tuple& __tuple, index_sequence<_Ids...>,
5346 basic_format_context<_Out, _CharT>& __fc) const
5347 { return _M_format_elems(std::get<_Ids>(__tuple)..., __fc); }
5348
5349 template<typename _Out>
5350 typename basic_format_context<_Out, _CharT>::iterator
5351 _M_format_elems(__maybe_const<_Tps, _CharT>&... __elems,
5352 basic_format_context<_Out, _CharT>& __fc) const
5353 {
5354 return __format::__format_padded(
5355 __fc, _M_spec,
5356 [this, &__elems...](basic_format_context<_Out, _CharT>& __nfc)
5357 {
5358 __nfc.advance_to(__format::__write(__nfc.out(), _M_open));
5359 _M_felems._M_format(__elems..., __nfc, _M_sep);
5360 return __format::__write(__nfc.out(), _M_close);
5361 });
5362 }
5363
5364 private:
5365 template<size_t... _Ids>
5366 struct __formatters_storage
5367 : __indexed_formatter_storage<_Ids, _Tps, _CharT>...
5368 {
5369 template<size_t _Id, typename _Up>
5370 using _Base = __indexed_formatter_storage<_Id, _Up, _CharT>;
5371
5372 constexpr void
5373 _M_parse()
5374 {
5375 (_Base<_Ids, _Tps>::_M_parse(), ...);
5376 }
5377
5378 template<typename _Out>
5379 void
5380 _M_format(__maybe_const<_Tps, _CharT>&... __elems,
5381 basic_format_context<_Out, _CharT>& __fc,
5382 _String_view __sep) const
5383 {
5384 (_Base<_Ids, _Tps>::_M_format(__elems, __fc, __sep), ...);
5385 }
5386
5387 constexpr void
5388 set_debug_format()
5389 {
5390 (_Base<_Ids, _Tps>::set_debug_format(), ...);
5391 }
5392 };
5393
5394 template<size_t... _Ids>
5395 static auto
5396 _S_create_storage(index_sequence<_Ids...>)
5397 -> __formatters_storage<_Ids...>;
5398 using _Formatters
5399 = decltype(_S_create_storage(index_sequence_for<_Tps...>()));
5400
5401 _Spec<_CharT> _M_spec{};
5402 _String_view _M_open = _Seps::_S_parens().substr(0, 1);
5403 _String_view _M_close = _Seps::_S_parens().substr(1, 1);
5404 _String_view _M_sep = _Seps::_S_comma();
5405 _Formatters _M_felems;
5406 };
5407
5408 template<typename _Tp>
5409 concept __is_map_formattable
5410 = __is_pair<_Tp> || (__is_tuple_v<_Tp> && tuple_size_v<_Tp> == 2);
5411
5412} // namespace __format
5413/// @endcond
5414
5415 // [format.tuple] Tuple formatter
5416 template<__format::__char _CharT, formattable<_CharT> _Fp,
5417 formattable<_CharT> _Sp>
5418 struct formatter<pair<_Fp, _Sp>, _CharT>
5419 : __format::__tuple_formatter<_CharT, remove_cvref_t<_Fp>,
5420 remove_cvref_t<_Sp>>
5421 {
5422 private:
5423 using __maybe_const_pair
5424 = __conditional_t<formattable<const _Fp, _CharT>
5425 && formattable<const _Sp, _CharT>,
5426 const pair<_Fp, _Sp>, pair<_Fp, _Sp>>;
5427 public:
5428 // We deviate from standard, that declares this as template accepting
5429 // unconstrained FormatContext type, which seems unimplementable.
5430 template<typename _Out>
5431 typename basic_format_context<_Out, _CharT>::iterator
5432 format(__maybe_const_pair& __p,
5433 basic_format_context<_Out, _CharT>& __fc) const
5434 { return this->_M_format_elems(__p.first, __p.second, __fc); }
5435 };
5436
5437 template<__format::__char _CharT, formattable<_CharT>... _Tps>
5438 struct formatter<tuple<_Tps...>, _CharT>
5439 : __format::__tuple_formatter<_CharT, remove_cvref_t<_Tps>...>
5440 {
5441 private:
5442 using __maybe_const_tuple
5443 = __conditional_t<(formattable<const _Tps, _CharT> && ...),
5444 const tuple<_Tps...>, tuple<_Tps...>>;
5445 public:
5446 // We deviate from standard, that declares this as template accepting
5447 // unconstrained FormatContext type, which seems unimplementable.
5448 template<typename _Out>
5449 typename basic_format_context<_Out, _CharT>::iterator
5450 format(__maybe_const_tuple& __t,
5451 basic_format_context<_Out, _CharT>& __fc) const
5452 { return this->_M_format(__t, index_sequence_for<_Tps...>(), __fc); }
5453 };
5454
5455 // [format.range.formatter], class template range_formatter
5456 template<typename _Tp, __format::__char _CharT>
5457 requires same_as<remove_cvref_t<_Tp>, _Tp> && formattable<_Tp, _CharT>
5458 class range_formatter
5459 {
5460 using _String_view = basic_string_view<_CharT>;
5461 using _Seps = __format::_Separators<_CharT>;
5462
5463 public:
5464 constexpr void
5465 set_separator(basic_string_view<_CharT> __sep) noexcept
5466 { _M_sep = __sep; }
5467
5468 constexpr void
5469 set_brackets(basic_string_view<_CharT> __open,
5470 basic_string_view<_CharT> __close) noexcept
5471 {
5472 _M_open = __open;
5473 _M_close = __close;
5474 }
5475
5476 constexpr formatter<_Tp, _CharT>&
5477 underlying() noexcept
5478 { return _M_fval; }
5479
5480 constexpr const formatter<_Tp, _CharT>&
5481 underlying() const noexcept
5482 { return _M_fval; }
5483
5484 // We deviate from standard, that declares this as template accepting
5485 // unconstrained ParseContext type, which seems unimplementable.
5486 constexpr typename basic_format_parse_context<_CharT>::iterator
5487 parse(basic_format_parse_context<_CharT>& __pc)
5488 {
5489 auto __first = __pc.begin();
5490 const auto __last = __pc.end();
5491 __format::_Spec<_CharT> __spec{};
5492 bool __no_brace = false;
5493
5494 auto __finished = [&]
5495 { return __first == __last || *__first == '}'; };
5496
5497 auto __finalize = [&]
5498 {
5499 _M_spec = __spec;
5500 return __first;
5501 };
5502
5503 auto __parse_val = [&](_String_view __nfs = _String_view())
5504 {
5505 basic_format_parse_context<_CharT> __npc(__nfs);
5506 if (_M_fval.parse(__npc) != __npc.end())
5507 __format::__failed_to_parse_format_spec();
5508 if constexpr (__format::__has_debug_format<formatter<_Tp, _CharT>>)
5509 _M_fval.set_debug_format();
5510 return __finalize();
5511 };
5512
5513 if (__finished())
5514 return __parse_val();
5515
5516 __first = __spec._M_parse_fill_and_align(__first, __last, "{:");
5517 if (__finished())
5518 return __parse_val();
5519
5520 __first = __spec._M_parse_width(__first, __last, __pc);
5521 if (__finished())
5522 return __parse_val();
5523
5524 if (*__first == '?')
5525 {
5526 ++__first;
5527 __spec._M_type = __format::_Pres_esc;
5528 if (__finished() || *__first != 's')
5529 __throw_format_error("format error: '?' is allowed only in"
5530 " combination with 's'");
5531 }
5532
5533 if (*__first == 's')
5534 {
5535 ++__first;
5536 if constexpr (same_as<_Tp, _CharT>)
5537 {
5538 if (__spec._M_type != __format::_Pres_esc)
5539 __spec._M_type = __format::_Pres_str;
5540 if (__finished())
5541 return __finalize();
5542 __throw_format_error("format error: element format specifier"
5543 " cannot be provided when 's' specifier is used");
5544 }
5545 else
5546 __throw_format_error("format error: 's' specifier requires"
5547 " range of character types");
5548 }
5549
5550 if (__finished())
5551 return __parse_val();
5552
5553 if (*__first == 'n')
5554 {
5555 ++__first;
5556 _M_open = _M_close = _String_view();
5557 __no_brace = true;
5558 }
5559
5560 if (__finished())
5561 return __parse_val();
5562
5563 if (*__first == 'm')
5564 {
5565 _String_view __m(__first, 1);
5566 ++__first;
5567 if constexpr (__format::__is_map_formattable<_Tp>)
5568 {
5569 _M_sep = _Seps::_S_comma();
5570 if (!__no_brace)
5571 {
5572 _M_open = _Seps::_S_braces().substr(0, 1);
5573 _M_close = _Seps::_S_braces().substr(1, 1);
5574 }
5575 if (__finished())
5576 return __parse_val(__m);
5577 __throw_format_error("format error: element format specifier"
5578 " cannot be provided when 'm' specifier is used");
5579 }
5580 else
5581 __throw_format_error("format error: 'm' specifier requires"
5582 " range of pairs or tuples of two elements");
5583 }
5584
5585 if (__finished())
5586 return __parse_val();
5587
5588 if (*__first == ':')
5589 {
5590 __pc.advance_to(++__first);
5591 __first = _M_fval.parse(__pc);
5592 }
5593
5594 if (__finished())
5595 return __finalize();
5596
5597 __format::__failed_to_parse_format_spec();
5598 }
5599
5600 // We deviate from standard, that declares this as template accepting
5601 // unconstrained FormatContext type, which seems unimplementable.
5602 template<ranges::input_range _Rg, typename _Out>
5603 requires formattable<ranges::range_reference_t<_Rg>, _CharT> &&
5604 same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>, _Tp>
5605 typename basic_format_context<_Out, _CharT>::iterator
5606 format(_Rg&& __rg, basic_format_context<_Out, _CharT>& __fc) const
5607 {
5608 using _Range = remove_reference_t<_Rg>;
5609 if constexpr (__format::__simply_formattable_range<_Range, _CharT>)
5610 return _M_format<const _Range>(__rg, __fc);
5611 else
5612 return _M_format(__rg, __fc);
5613 }
5614
5615 private:
5616 template<ranges::input_range _Rg, typename _Out>
5617 typename basic_format_context<_Out, _CharT>::iterator
5618 _M_format(_Rg& __rg, basic_format_context<_Out, _CharT>& __fc) const
5619 {
5620 if constexpr (same_as<_Tp, _CharT>)
5621 if (_M_spec._M_type == __format::_Pres_str
5622 || _M_spec._M_type == __format::_Pres_esc)
5623 {
5624 __format::__formatter_str __fstr(_M_spec);
5625 return __fstr._M_format_range(__rg, __fc);
5626 }
5627 return __format::__format_padded(
5628 __fc, _M_spec,
5629 [this, &__rg](basic_format_context<_Out, _CharT>& __nfc)
5630 { return _M_format_elems(__rg, __nfc); });
5631 }
5632
5633
5634 template<ranges::input_range _Rg, typename _Out>
5635 typename basic_format_context<_Out, _CharT>::iterator
5636 _M_format_elems(_Rg& __rg,
5637 basic_format_context<_Out, _CharT>& __fc) const
5638 {
5639 auto __out = __format::__write(__fc.out(), _M_open);
5640
5641 auto __first = ranges::begin(__rg);
5642 auto const __last = ranges::end(__rg);
5643 if (__first == __last)
5644 return __format::__write(__out, _M_close);
5645
5646 __fc.advance_to(__out);
5647 __out = _M_fval.format(*__first, __fc);
5648 for (++__first; __first != __last; ++__first)
5649 {
5650 __out = __format::__write(__out, _M_sep);
5651 __fc.advance_to(__out);
5652 __out = _M_fval.format(*__first, __fc);
5653 }
5654
5655 return __format::__write(__out, _M_close);
5656 }
5657
5658 __format::_Spec<_CharT> _M_spec{};
5659 _String_view _M_open = _Seps::_S_squares().substr(0, 1);
5660 _String_view _M_close = _Seps::_S_squares().substr(1, 1);
5661 _String_view _M_sep = _Seps::_S_comma();
5662 formatter<_Tp, _CharT> _M_fval;
5663 };
5664
5665 // In standard this is shown as inheriting from specialization of
5666 // exposition only specialization for range-default-formatter for
5667 // each range_format. We opt for simpler implementation.
5668 // [format.range.fmtmap], [format.range.fmtset], [format.range.fmtstr],
5669 // specializations for maps, sets, and strings
5670 template<ranges::input_range _Rg, __format::__char _CharT>
5671 requires (format_kind<_Rg> != range_format::disabled)
5672 && formattable<ranges::range_reference_t<_Rg>, _CharT>
5673 struct formatter<_Rg, _CharT>
5674 {
5675 private:
5676 static const bool _S_range_format_is_string =
5677 (format_kind<_Rg> == range_format::string)
5678 || (format_kind<_Rg> == range_format::debug_string);
5679 using _Vt = remove_cvref_t<
5680 ranges::range_reference_t<
5681 __format::__maybe_const_range<_Rg, _CharT>>>;
5682
5683 static consteval bool _S_is_correct()
5684 {
5685 if constexpr (_S_range_format_is_string)
5686 static_assert(same_as<_Vt, _CharT>);
5687 return true;
5688 }
5689
5690 static_assert(_S_is_correct());
5691
5692 public:
5693 constexpr formatter() noexcept
5694 {
5695 using _Seps = __format::_Separators<_CharT>;
5696 if constexpr (format_kind<_Rg> == range_format::map)
5697 {
5698 static_assert(__format::__is_map_formattable<_Vt>);
5699 _M_under.set_brackets(_Seps::_S_braces().substr(0, 1),
5700 _Seps::_S_braces().substr(1, 1));
5701 _M_under.underlying().set_brackets({}, {});
5702 _M_under.underlying().set_separator(_Seps::_S_colon());
5703 }
5704 else if constexpr (format_kind<_Rg> == range_format::set)
5705 _M_under.set_brackets(_Seps::_S_braces().substr(0, 1),
5706 _Seps::_S_braces().substr(1, 1));
5707 }
5708
5709 constexpr void
5710 set_separator(basic_string_view<_CharT> __sep) noexcept
5711 requires (!_S_range_format_is_string)
5712 { _M_under.set_separator(__sep); }
5713
5714 constexpr void
5715 set_brackets(basic_string_view<_CharT> __open,
5716 basic_string_view<_CharT> __close) noexcept
5717 requires (!_S_range_format_is_string)
5718 { _M_under.set_brackets(__open, __close); }
5719
5720 // We deviate from standard, that declares this as template accepting
5721 // unconstrained ParseContext type, which seems unimplementable.
5722 constexpr typename basic_format_parse_context<_CharT>::iterator
5723 parse(basic_format_parse_context<_CharT>& __pc)
5724 {
5725 auto __res = _M_under.parse(__pc);
5726 if constexpr (format_kind<_Rg> == range_format::debug_string)
5727 _M_under.set_debug_format();
5728 return __res;
5729 }
5730
5731 // We deviate from standard, that declares this as template accepting
5732 // unconstrained FormatContext type, which seems unimplementable.
5733 template<typename _Out>
5734 typename basic_format_context<_Out, _CharT>::iterator
5735 format(__format::__maybe_const_range<_Rg, _CharT>& __rg,
5736 basic_format_context<_Out, _CharT>& __fc) const
5737 {
5738 if constexpr (_S_range_format_is_string)
5739 return _M_under._M_format_range(__rg, __fc);
5740 else
5741 return _M_under.format(__rg, __fc);
5742 }
5743
5744 private:
5745 using _Formatter_under
5746 = __conditional_t<_S_range_format_is_string,
5747 __format::__formatter_str<_CharT>,
5748 range_formatter<_Vt, _CharT>>;
5749 _Formatter_under _M_under;
5750 };
5751#endif // C++23 formatting ranges
5752#undef _GLIBCXX_WIDEN
5753
5754_GLIBCXX_END_NAMESPACE_VERSION
5755} // namespace std
5756#endif // __cpp_lib_format
5757#pragma GCC diagnostic pop
5758#endif // _GLIBCXX_FORMAT
constexpr complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
Definition complex:434
_Tp arg(const complex< _Tp > &)
Return phase angle of z.
Definition complex:991
typename remove_reference< _Tp >::type remove_reference_t
Alias template for remove_reference.
Definition type_traits:1798
typename make_unsigned< _Tp >::type make_unsigned_t
Alias template for make_unsigned.
Definition type_traits:2141
pair(_T1, _T2) -> pair< _T1, _T2 >
Two pairs are equal iff their members are equal.
constexpr _Tp * addressof(_Tp &__r) noexcept
Returns the actual address of the object or function referenced by r, even in the presence of an over...
Definition move.h:176
constexpr std::remove_reference< _Tp >::type && move(_Tp &&__t) noexcept
Convert a value to an rvalue.
Definition move.h:138
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
Definition move.h:72
_Tp * end(valarray< _Tp > &__va) noexcept
Return an iterator pointing to one past the last element of the valarray.
Definition valarray:1251
_Tp * begin(valarray< _Tp > &__va) noexcept
Return an iterator pointing to the first element of the valarray.
Definition valarray:1229
const _Facet & use_facet(const locale &__loc)
Return a facet.
basic_string< char > string
A string of char.
Definition stringfwd.h:79
ISO C++ entities toplevel namespace is std.
chars_format
floating-point format for primitive numerical conversion
Definition charconv:626
_CharT toupper(_CharT __c, const locale &__loc)
Convenience interface to ctype.toupper(__c).
constexpr auto size(const _Container &__cont) noexcept(noexcept(__cont.size())) -> decltype(__cont.size())
Return the size of a container.
__numeric_traits_integer< _Tp > __int_traits
Convenience alias for __numeric_traits<integer-type>.
One of two subclasses of exception.
Definition stdexcept:222
A non-owning reference to a string.
Definition string_view:109
Managing sequences of characters and character-like objects.
constexpr size_type size() const noexcept
Returns the number of characters in the string, not including any null-termination.
constexpr void reserve(size_type __res_arg)
Attempt to preallocate enough memory for specified number of characters.
constexpr const _CharT * data() const noexcept
Return const pointer to contents.
constexpr basic_string substr(size_type __pos=0, size_type __n=npos) const
Get a substring.
constexpr void __resize_and_overwrite(size_type __n, _Operation __op)
Non-standard version of resize_and_overwrite for C++11 and above.
constexpr basic_string & append(const basic_string &__str)
Append a string to this string.
constexpr iterator insert(const_iterator __p, size_type __n, _CharT __c)
Insert multiple characters.
constexpr size_type capacity() const noexcept
constexpr bool empty() const noexcept
A standard container which offers fixed time access to individual elements in any order.
Definition stl_vector.h:459