1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP___CHRONO_FORMATTER_H
11#define _LIBCPP___CHRONO_FORMATTER_H
12
13#include <__chrono/calendar.h>
14#include <__chrono/concepts.h>
15#include <__chrono/convert_to_tm.h>
16#include <__chrono/day.h>
17#include <__chrono/duration.h>
18#include <__chrono/file_clock.h>
19#include <__chrono/hh_mm_ss.h>
20#include <__chrono/month.h>
21#include <__chrono/month_weekday.h>
22#include <__chrono/monthday.h>
23#include <__chrono/ostream.h>
24#include <__chrono/parser_std_format_spec.h>
25#include <__chrono/statically_widen.h>
26#include <__chrono/system_clock.h>
27#include <__chrono/time_point.h>
28#include <__chrono/weekday.h>
29#include <__chrono/year.h>
30#include <__chrono/year_month.h>
31#include <__chrono/year_month_day.h>
32#include <__chrono/year_month_weekday.h>
33#include <__concepts/arithmetic.h>
34#include <__concepts/same_as.h>
35#include <__config>
36#include <__format/concepts.h>
37#include <__format/format_error.h>
38#include <__format/format_functions.h>
39#include <__format/format_parse_context.h>
40#include <__format/formatter.h>
41#include <__format/parser_std_format_spec.h>
42#include <__format/write_escaped.h>
43#include <__memory/addressof.h>
44#include <cmath>
45#include <ctime>
46#include <sstream>
47#include <string_view>
48
49#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
50#  pragma GCC system_header
51#endif
52
53_LIBCPP_BEGIN_NAMESPACE_STD
54
55#if _LIBCPP_STD_VER >= 20
56
57namespace __formatter {
58
59/// Formats a time based on a tm struct.
60///
61/// This formatter passes the formatting to time_put which uses strftime. When
62/// the value is outside the valid range it's unspecified what strftime will
63/// output. For example weekday 8 can print 1 when the day is processed modulo
64/// 7 since that handles the Sunday for 0-based weekday. It can also print 8 if
65/// 7 is handled as a special case.
66///
67/// The Standard doesn't specify what to do in this case so the result depends
68/// on the result of the underlying code.
69///
70/// \pre When the (abbreviated) weekday or month name are used, the caller
71///      validates whether the value is valid. So the caller handles that
72///      requirement of Table 97: Meaning of conversion specifiers
73///      [tab:time.format.spec].
74///
75/// When no chrono-specs are provided it uses the stream formatter.
76
77// For tiny ratios it's not possible to convert a duration to a hh_mm_ss. This
78// fails compile-time due to the limited precision of the ratio (64-bit is too
79// small). Therefore a duration uses its own conversion.
80template <class _CharT, class _Rep, class _Period>
81_LIBCPP_HIDE_FROM_ABI void
82__format_sub_seconds(const chrono::duration<_Rep, _Period>& __value, basic_stringstream<_CharT>& __sstr) {
83  __sstr << std::use_facet<numpunct<_CharT>>(__sstr.getloc()).decimal_point();
84
85  using __duration = chrono::duration<_Rep, _Period>;
86
87  auto __fraction = __value - chrono::duration_cast<chrono::seconds>(__value);
88  if constexpr (chrono::treat_as_floating_point_v<_Rep>)
89    // When the floating-point value has digits itself they are ignored based
90    // on the wording in [tab:time.format.spec]
91    //   If the precision of the input cannot be exactly represented with
92    //   seconds, then the format is a decimal floating-point number with a
93    //   fixed format and a precision matching that of the precision of the
94    //   input (or to a microseconds precision if the conversion to
95    //   floating-point decimal seconds cannot be made within 18 fractional
96    //   digits).
97    //
98    // This matches the behaviour of MSVC STL, fmtlib interprets this
99    // differently and uses 3 decimals.
100    // https://godbolt.org/z/6dsbnW8ba
101    std::format_to(std::ostreambuf_iterator<_CharT>{__sstr},
102                   _LIBCPP_STATICALLY_WIDEN(_CharT, "{:0{}.0f}"),
103                   chrono::duration_cast<typename chrono::hh_mm_ss<__duration>::precision>(__fraction).count(),
104                   chrono::hh_mm_ss<__duration>::fractional_width);
105  else
106    std::format_to(std::ostreambuf_iterator<_CharT>{__sstr},
107                   _LIBCPP_STATICALLY_WIDEN(_CharT, "{:0{}}"),
108                   chrono::duration_cast<typename chrono::hh_mm_ss<__duration>::precision>(__fraction).count(),
109                   chrono::hh_mm_ss<__duration>::fractional_width);
110}
111
112template <class _CharT, __is_time_point _Tp>
113_LIBCPP_HIDE_FROM_ABI void __format_sub_seconds(const _Tp& __value, basic_stringstream<_CharT>& __sstr) {
114  __formatter::__format_sub_seconds(__value.time_since_epoch(), __sstr);
115}
116
117template <class _CharT, class _Duration>
118_LIBCPP_HIDE_FROM_ABI void
119__format_sub_seconds(const chrono::hh_mm_ss<_Duration>& __value, basic_stringstream<_CharT>& __sstr) {
120  __sstr << std::use_facet<numpunct<_CharT>>(__sstr.getloc()).decimal_point();
121  if constexpr (chrono::treat_as_floating_point_v<typename _Duration::rep>)
122    std::format_to(std::ostreambuf_iterator<_CharT>{__sstr},
123                   _LIBCPP_STATICALLY_WIDEN(_CharT, "{:0{}.0f}"),
124                   __value.subseconds().count(),
125                   __value.fractional_width);
126  else
127    std::format_to(std::ostreambuf_iterator<_CharT>{__sstr},
128                   _LIBCPP_STATICALLY_WIDEN(_CharT, "{:0{}}"),
129                   __value.subseconds().count(),
130                   __value.fractional_width);
131}
132
133template <class _Tp>
134consteval bool __use_fraction() {
135  if constexpr (__is_time_point<_Tp>)
136    return chrono::hh_mm_ss<typename _Tp::duration>::fractional_width;
137  else if constexpr (chrono::__is_duration<_Tp>::value)
138    return chrono::hh_mm_ss<_Tp>::fractional_width;
139  else if constexpr (__is_hh_mm_ss<_Tp>)
140    return _Tp::fractional_width;
141  else
142    return false;
143}
144
145template <class _CharT>
146_LIBCPP_HIDE_FROM_ABI void __format_year(int __year, basic_stringstream<_CharT>& __sstr) {
147  if (__year < 0) {
148    __sstr << _CharT('-');
149    __year = -__year;
150  }
151
152  // TODO FMT Write an issue
153  //   If the result has less than four digits it is zero-padded with 0 to two digits.
154  // is less -> has less
155  // left-padded -> zero-padded, otherwise the proper value would be 000-0.
156
157  // Note according to the wording it should be left padded, which is odd.
158  __sstr << std::format(_LIBCPP_STATICALLY_WIDEN(_CharT, "{:04}"), __year);
159}
160
161template <class _CharT>
162_LIBCPP_HIDE_FROM_ABI void __format_century(int __year, basic_stringstream<_CharT>& __sstr) {
163  // TODO FMT Write an issue
164  // [tab:time.format.spec]
165  //   %C The year divided by 100 using floored division. If the result is a
166  //   single decimal digit, it is prefixed with 0.
167
168  bool __negative = __year < 0;
169  int __century   = (__year - (99 * __negative)) / 100; // floored division
170  __sstr << std::format(_LIBCPP_STATICALLY_WIDEN(_CharT, "{:02}"), __century);
171}
172
173template <class _CharT, class _Tp>
174_LIBCPP_HIDE_FROM_ABI void __format_chrono_using_chrono_specs(
175    const _Tp& __value, basic_stringstream<_CharT>& __sstr, basic_string_view<_CharT> __chrono_specs) {
176  tm __t              = std::__convert_to_tm<tm>(__value);
177  const auto& __facet = std::use_facet<time_put<_CharT>>(__sstr.getloc());
178  for (auto __it = __chrono_specs.begin(); __it != __chrono_specs.end(); ++__it) {
179    if (*__it == _CharT('%')) {
180      auto __s = __it;
181      ++__it;
182      // We only handle the types that can't be directly handled by time_put.
183      // (as an optimization n, t, and % are also handled directly.)
184      switch (*__it) {
185      case _CharT('n'):
186        __sstr << _CharT('\n');
187        break;
188      case _CharT('t'):
189        __sstr << _CharT('\t');
190        break;
191      case _CharT('%'):
192        __sstr << *__it;
193        break;
194
195      case _CharT('C'): {
196        // strftime's output is only defined in the range [00, 99].
197        int __year = __t.tm_year + 1900;
198        if (__year < 1000 || __year > 9999)
199          __formatter::__format_century(__year, __sstr);
200        else
201          __facet.put(
202              {__sstr}, __sstr, _CharT(' '), std::addressof(__t), std::to_address(__s), std::to_address(__it + 1));
203      } break;
204
205      case _CharT('j'):
206        if constexpr (chrono::__is_duration<_Tp>::value)
207          // Converting a duration where the period has a small ratio to days
208          // may fail to compile. This due to loss of precision in the
209          // conversion. In order to avoid that issue convert to seconds as
210          // an intemediate step.
211          __sstr << chrono::duration_cast<chrono::days>(chrono::duration_cast<chrono::seconds>(__value)).count();
212        else
213          __facet.put(
214              {__sstr}, __sstr, _CharT(' '), std::addressof(__t), std::to_address(__s), std::to_address(__it + 1));
215        break;
216
217      case _CharT('q'):
218        if constexpr (chrono::__is_duration<_Tp>::value) {
219          __sstr << chrono::__units_suffix<_CharT, typename _Tp::period>();
220          break;
221        }
222        __builtin_unreachable();
223
224      case _CharT('Q'):
225        // TODO FMT Determine the proper ideas
226        // - Should it honour the precision?
227        // - Shoult it honour the locale setting for the separators?
228        // The wording for Q doesn't use the word locale and the effect of
229        // precision is unspecified.
230        //
231        // MSVC STL ignores precision but uses separator
232        // FMT honours precision and has a bug for separator
233        // https://godbolt.org/z/78b7sMxns
234        if constexpr (chrono::__is_duration<_Tp>::value) {
235          __sstr << std::format(_LIBCPP_STATICALLY_WIDEN(_CharT, "{}"), __value.count());
236          break;
237        }
238        __builtin_unreachable();
239
240      case _CharT('S'):
241      case _CharT('T'):
242        __facet.put(
243            {__sstr}, __sstr, _CharT(' '), std::addressof(__t), std::to_address(__s), std::to_address(__it + 1));
244        if constexpr (__use_fraction<_Tp>())
245          __formatter::__format_sub_seconds(__value, __sstr);
246        break;
247
248        // Unlike time_put and strftime the formatting library requires %Y
249        //
250        // [tab:time.format.spec]
251        //   The year as a decimal number. If the result is less than four digits
252        //   it is left-padded with 0 to four digits.
253        //
254        // This means years in the range (-1000, 1000) need manual formatting.
255        // It's unclear whether %EY needs the same treatment. For example the
256        // Japanese EY contains the era name and year. This is zero-padded to 2
257        // digits in time_put (note that older glibc versions didn't do
258        // padding.) However most eras won't reach 100 years, let alone 1000.
259        // So padding to 4 digits seems unwanted for Japanese.
260        //
261        // The same applies to %Ex since that too depends on the era.
262        //
263        // %x the locale's date representation is currently doesn't handle the
264        // zero-padding too.
265        //
266        // The 4 digits can be implemented better at a later time. On POSIX
267        // systems the required information can be extracted by nl_langinfo
268        // https://man7.org/linux/man-pages/man3/nl_langinfo.3.html
269        //
270        // Note since year < -1000 is expected to be rare it uses the more
271        // expensive year routine.
272        //
273        // TODO FMT evaluate the comment above.
274
275#  if defined(__GLIBC__) || defined(_AIX) || defined(_WIN32)
276      case _CharT('y'):
277        // Glibc fails for negative values, AIX for positive values too.
278        __sstr << std::format(_LIBCPP_STATICALLY_WIDEN(_CharT, "{:02}"), (std::abs(__t.tm_year + 1900)) % 100);
279        break;
280#  endif // defined(__GLIBC__) || defined(_AIX) || defined(_WIN32)
281
282      case _CharT('Y'):
283        // Depending on the platform's libc the range of supported years is
284        // limited. Intead of of testing all conditions use the internal
285        // implementation unconditionally.
286        __formatter::__format_year(__t.tm_year + 1900, __sstr);
287        break;
288
289      case _CharT('F'): {
290        int __year = __t.tm_year + 1900;
291        if (__year < 1000) {
292          __formatter::__format_year(__year, __sstr);
293          __sstr << std::format(_LIBCPP_STATICALLY_WIDEN(_CharT, "-{:02}-{:02}"), __t.tm_mon + 1, __t.tm_mday);
294        } else
295          __facet.put(
296              {__sstr}, __sstr, _CharT(' '), std::addressof(__t), std::to_address(__s), std::to_address(__it + 1));
297      } break;
298
299      case _CharT('Z'):
300        // TODO FMT Add proper timezone support.
301        __sstr << _LIBCPP_STATICALLY_WIDEN(_CharT, "UTC");
302        break;
303
304      case _CharT('O'):
305        if constexpr (__use_fraction<_Tp>()) {
306          // Handle OS using the normal representation for the non-fractional
307          // part. There seems to be no locale information regarding how the
308          // fractional part should be formatted.
309          if (*(__it + 1) == 'S') {
310            ++__it;
311            __facet.put(
312                {__sstr}, __sstr, _CharT(' '), std::addressof(__t), std::to_address(__s), std::to_address(__it + 1));
313            __formatter::__format_sub_seconds(__value, __sstr);
314            break;
315          }
316        }
317        [[fallthrough]];
318      case _CharT('E'):
319        ++__it;
320        [[fallthrough]];
321      default:
322        __facet.put(
323            {__sstr}, __sstr, _CharT(' '), std::addressof(__t), std::to_address(__s), std::to_address(__it + 1));
324        break;
325      }
326    } else {
327      __sstr << *__it;
328    }
329  }
330}
331
332template <class _Tp>
333_LIBCPP_HIDE_FROM_ABI constexpr bool __weekday_ok(const _Tp& __value) {
334  if constexpr (__is_time_point<_Tp>)
335    return true;
336  else if constexpr (same_as<_Tp, chrono::day>)
337    return true;
338  else if constexpr (same_as<_Tp, chrono::month>)
339    return __value.ok();
340  else if constexpr (same_as<_Tp, chrono::year>)
341    return true;
342  else if constexpr (same_as<_Tp, chrono::weekday>)
343    return true;
344  else if constexpr (same_as<_Tp, chrono::weekday_indexed>)
345    return true;
346  else if constexpr (same_as<_Tp, chrono::weekday_last>)
347    return true;
348  else if constexpr (same_as<_Tp, chrono::month_day>)
349    return true;
350  else if constexpr (same_as<_Tp, chrono::month_day_last>)
351    return true;
352  else if constexpr (same_as<_Tp, chrono::month_weekday>)
353    return true;
354  else if constexpr (same_as<_Tp, chrono::month_weekday_last>)
355    return true;
356  else if constexpr (same_as<_Tp, chrono::year_month>)
357    return true;
358  else if constexpr (same_as<_Tp, chrono::year_month_day>)
359    return __value.ok();
360  else if constexpr (same_as<_Tp, chrono::year_month_day_last>)
361    return __value.ok();
362  else if constexpr (same_as<_Tp, chrono::year_month_weekday>)
363    return __value.weekday().ok();
364  else if constexpr (same_as<_Tp, chrono::year_month_weekday_last>)
365    return __value.weekday().ok();
366  else if constexpr (__is_hh_mm_ss<_Tp>)
367    return true;
368  else
369    static_assert(sizeof(_Tp) == 0, "Add the missing type specialization");
370}
371
372template <class _Tp>
373_LIBCPP_HIDE_FROM_ABI constexpr bool __weekday_name_ok(const _Tp& __value) {
374  if constexpr (__is_time_point<_Tp>)
375    return true;
376  else if constexpr (same_as<_Tp, chrono::day>)
377    return true;
378  else if constexpr (same_as<_Tp, chrono::month>)
379    return __value.ok();
380  else if constexpr (same_as<_Tp, chrono::year>)
381    return true;
382  else if constexpr (same_as<_Tp, chrono::weekday>)
383    return __value.ok();
384  else if constexpr (same_as<_Tp, chrono::weekday_indexed>)
385    return __value.weekday().ok();
386  else if constexpr (same_as<_Tp, chrono::weekday_last>)
387    return __value.weekday().ok();
388  else if constexpr (same_as<_Tp, chrono::month_day>)
389    return true;
390  else if constexpr (same_as<_Tp, chrono::month_day_last>)
391    return true;
392  else if constexpr (same_as<_Tp, chrono::month_weekday>)
393    return __value.weekday_indexed().ok();
394  else if constexpr (same_as<_Tp, chrono::month_weekday_last>)
395    return __value.weekday_indexed().ok();
396  else if constexpr (same_as<_Tp, chrono::year_month>)
397    return true;
398  else if constexpr (same_as<_Tp, chrono::year_month_day>)
399    return __value.ok();
400  else if constexpr (same_as<_Tp, chrono::year_month_day_last>)
401    return __value.ok();
402  else if constexpr (same_as<_Tp, chrono::year_month_weekday>)
403    return __value.weekday().ok();
404  else if constexpr (same_as<_Tp, chrono::year_month_weekday_last>)
405    return __value.weekday().ok();
406  else if constexpr (__is_hh_mm_ss<_Tp>)
407    return true;
408  else
409    static_assert(sizeof(_Tp) == 0, "Add the missing type specialization");
410}
411
412template <class _Tp>
413_LIBCPP_HIDE_FROM_ABI constexpr bool __date_ok(const _Tp& __value) {
414  if constexpr (__is_time_point<_Tp>)
415    return true;
416  else if constexpr (same_as<_Tp, chrono::day>)
417    return true;
418  else if constexpr (same_as<_Tp, chrono::month>)
419    return __value.ok();
420  else if constexpr (same_as<_Tp, chrono::year>)
421    return true;
422  else if constexpr (same_as<_Tp, chrono::weekday>)
423    return true;
424  else if constexpr (same_as<_Tp, chrono::weekday_indexed>)
425    return true;
426  else if constexpr (same_as<_Tp, chrono::weekday_last>)
427    return true;
428  else if constexpr (same_as<_Tp, chrono::month_day>)
429    return true;
430  else if constexpr (same_as<_Tp, chrono::month_day_last>)
431    return true;
432  else if constexpr (same_as<_Tp, chrono::month_weekday>)
433    return true;
434  else if constexpr (same_as<_Tp, chrono::month_weekday_last>)
435    return true;
436  else if constexpr (same_as<_Tp, chrono::year_month>)
437    return true;
438  else if constexpr (same_as<_Tp, chrono::year_month_day>)
439    return __value.ok();
440  else if constexpr (same_as<_Tp, chrono::year_month_day_last>)
441    return __value.ok();
442  else if constexpr (same_as<_Tp, chrono::year_month_weekday>)
443    return __value.ok();
444  else if constexpr (same_as<_Tp, chrono::year_month_weekday_last>)
445    return __value.ok();
446  else if constexpr (__is_hh_mm_ss<_Tp>)
447    return true;
448  else
449    static_assert(sizeof(_Tp) == 0, "Add the missing type specialization");
450}
451
452template <class _Tp>
453_LIBCPP_HIDE_FROM_ABI constexpr bool __month_name_ok(const _Tp& __value) {
454  if constexpr (__is_time_point<_Tp>)
455    return true;
456  else if constexpr (same_as<_Tp, chrono::day>)
457    return true;
458  else if constexpr (same_as<_Tp, chrono::month>)
459    return __value.ok();
460  else if constexpr (same_as<_Tp, chrono::year>)
461    return true;
462  else if constexpr (same_as<_Tp, chrono::weekday>)
463    return true;
464  else if constexpr (same_as<_Tp, chrono::weekday_indexed>)
465    return true;
466  else if constexpr (same_as<_Tp, chrono::weekday_last>)
467    return true;
468  else if constexpr (same_as<_Tp, chrono::month_day>)
469    return __value.month().ok();
470  else if constexpr (same_as<_Tp, chrono::month_day_last>)
471    return __value.month().ok();
472  else if constexpr (same_as<_Tp, chrono::month_weekday>)
473    return __value.month().ok();
474  else if constexpr (same_as<_Tp, chrono::month_weekday_last>)
475    return __value.month().ok();
476  else if constexpr (same_as<_Tp, chrono::year_month>)
477    return __value.month().ok();
478  else if constexpr (same_as<_Tp, chrono::year_month_day>)
479    return __value.month().ok();
480  else if constexpr (same_as<_Tp, chrono::year_month_day_last>)
481    return __value.month().ok();
482  else if constexpr (same_as<_Tp, chrono::year_month_weekday>)
483    return __value.month().ok();
484  else if constexpr (same_as<_Tp, chrono::year_month_weekday_last>)
485    return __value.month().ok();
486  else if constexpr (__is_hh_mm_ss<_Tp>)
487    return true;
488  else
489    static_assert(sizeof(_Tp) == 0, "Add the missing type specialization");
490}
491
492template <class _CharT, class _Tp, class _FormatContext>
493_LIBCPP_HIDE_FROM_ABI auto
494__format_chrono(const _Tp& __value,
495                _FormatContext& __ctx,
496                __format_spec::__parsed_specifications<_CharT> __specs,
497                basic_string_view<_CharT> __chrono_specs) {
498  basic_stringstream<_CharT> __sstr;
499  // [time.format]/2
500  // 2.1 - the "C" locale if the L option is not present in chrono-format-spec, otherwise
501  // 2.2 - the locale passed to the formatting function if any, otherwise
502  // 2.3 - the global locale.
503  // Note that the __ctx's locale() call does 2.2 and 2.3.
504  if (__specs.__chrono_.__locale_specific_form_)
505    __sstr.imbue(__ctx.locale());
506  else
507    __sstr.imbue(locale::classic());
508
509  if (__chrono_specs.empty())
510    __sstr << __value;
511  else {
512    if constexpr (chrono::__is_duration<_Tp>::value) {
513      if (__value < __value.zero())
514        __sstr << _CharT('-');
515      __formatter::__format_chrono_using_chrono_specs(chrono::abs(__value), __sstr, __chrono_specs);
516      // TODO FMT When keeping the precision it will truncate the string.
517      // Note that the behaviour what the precision does isn't specified.
518      __specs.__precision_ = -1;
519    } else {
520      // Test __weekday_name_ before __weekday_ to give a better error.
521      if (__specs.__chrono_.__weekday_name_ && !__formatter::__weekday_name_ok(__value))
522        std::__throw_format_error("Formatting a weekday name needs a valid weekday");
523
524      if (__specs.__chrono_.__weekday_ && !__formatter::__weekday_ok(__value))
525        std::__throw_format_error("Formatting a weekday needs a valid weekday");
526
527      if (__specs.__chrono_.__day_of_year_ && !__formatter::__date_ok(__value))
528        std::__throw_format_error("Formatting a day of year needs a valid date");
529
530      if (__specs.__chrono_.__week_of_year_ && !__formatter::__date_ok(__value))
531        std::__throw_format_error("Formatting a week of year needs a valid date");
532
533      if (__specs.__chrono_.__month_name_ && !__formatter::__month_name_ok(__value))
534        std::__throw_format_error("Formatting a month name from an invalid month number");
535
536      if constexpr (__is_hh_mm_ss<_Tp>) {
537        // Note this is a pedantic intepretation of the Standard. A hh_mm_ss
538        // is no longer a time_of_day and can store an arbitrary number of
539        // hours. A number of hours in a 12 or 24 hour clock can't represent
540        // 24 hours or more. The functions std::chrono::make12 and
541        // std::chrono::make24 reaffirm this view point.
542        //
543        // Interestingly this will be the only output stream function that
544        // throws.
545        //
546        // TODO FMT The wording probably needs to be adapted to
547        // - The displayed hours is hh_mm_ss.hours() % 24
548        // - It should probably allow %j in the same fashion as duration.
549        // - The stream formatter should change its output when hours >= 24
550        //   - Write it as not valid,
551        //   - or write the number of days.
552        if (__specs.__chrono_.__hour_ && __value.hours().count() > 23)
553          std::__throw_format_error("Formatting a hour needs a valid value");
554
555        if (__value.is_negative())
556          __sstr << _CharT('-');
557      }
558
559      __formatter::__format_chrono_using_chrono_specs(__value, __sstr, __chrono_specs);
560    }
561  }
562
563  return __formatter::__write_string(__sstr.view(), __ctx.out(), __specs);
564}
565
566} // namespace __formatter
567
568template <__fmt_char_type _CharT>
569struct _LIBCPP_TEMPLATE_VIS __formatter_chrono {
570public:
571  template <class _ParseContext>
572  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator
573  __parse(_ParseContext& __ctx, __format_spec::__fields __fields, __format_spec::__flags __flags) {
574    return __parser_.__parse(__ctx, __fields, __flags);
575  }
576
577  template <class _Tp, class _FormatContext>
578  _LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator format(const _Tp& __value, _FormatContext& __ctx) const {
579    return __formatter::__format_chrono(
580        __value, __ctx, __parser_.__parser_.__get_parsed_chrono_specifications(__ctx), __parser_.__chrono_specs_);
581  }
582
583  __format_spec::__parser_chrono<_CharT> __parser_;
584};
585
586template <class _Duration, __fmt_char_type _CharT>
587struct _LIBCPP_TEMPLATE_VIS formatter<chrono::sys_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
588public:
589  using _Base = __formatter_chrono<_CharT>;
590
591  template <class _ParseContext>
592  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
593    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__clock);
594  }
595};
596
597template <class _Duration, __fmt_char_type _CharT>
598struct _LIBCPP_TEMPLATE_VIS formatter<chrono::file_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
599public:
600  using _Base = __formatter_chrono<_CharT>;
601
602  template <class _ParseContext>
603  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
604    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__clock);
605  }
606};
607
608template <class _Duration, __fmt_char_type _CharT>
609struct _LIBCPP_TEMPLATE_VIS formatter<chrono::local_time<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
610public:
611  using _Base = __formatter_chrono<_CharT>;
612
613  template <class _ParseContext>
614  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
615    // The flags are not __clock since there is no associated time-zone.
616    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__date_time);
617  }
618};
619
620template <class _Rep, class _Period, __fmt_char_type _CharT>
621struct formatter<chrono::duration<_Rep, _Period>, _CharT> : public __formatter_chrono<_CharT> {
622public:
623  using _Base = __formatter_chrono<_CharT>;
624
625  template <class _ParseContext>
626  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
627    // [time.format]/1
628    // Giving a precision specification in the chrono-format-spec is valid only
629    // for std::chrono::duration types where the representation type Rep is a
630    // floating-point type. For all other Rep types, an exception of type
631    // format_error is thrown if the chrono-format-spec contains a precision
632    // specification.
633    //
634    // Note this doesn't refer to chrono::treat_as_floating_point_v<_Rep>.
635    if constexpr (std::floating_point<_Rep>)
636      return _Base::__parse(__ctx, __format_spec::__fields_chrono_fractional, __format_spec::__flags::__duration);
637    else
638      return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__duration);
639  }
640};
641
642template <__fmt_char_type _CharT>
643struct _LIBCPP_TEMPLATE_VIS formatter<chrono::day, _CharT> : public __formatter_chrono<_CharT> {
644public:
645  using _Base = __formatter_chrono<_CharT>;
646
647  template <class _ParseContext>
648  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
649    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__day);
650  }
651};
652
653template <__fmt_char_type _CharT>
654struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month, _CharT> : public __formatter_chrono<_CharT> {
655public:
656  using _Base = __formatter_chrono<_CharT>;
657
658  template <class _ParseContext>
659  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
660    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__month);
661  }
662};
663
664template <__fmt_char_type _CharT>
665struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year, _CharT> : public __formatter_chrono<_CharT> {
666public:
667  using _Base = __formatter_chrono<_CharT>;
668
669  template <class _ParseContext>
670  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
671    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__year);
672  }
673};
674
675template <__fmt_char_type _CharT>
676struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday, _CharT> : public __formatter_chrono<_CharT> {
677public:
678  using _Base = __formatter_chrono<_CharT>;
679
680  template <class _ParseContext>
681  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
682    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__weekday);
683  }
684};
685
686template <__fmt_char_type _CharT>
687struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday_indexed, _CharT> : public __formatter_chrono<_CharT> {
688public:
689  using _Base = __formatter_chrono<_CharT>;
690
691  template <class _ParseContext>
692  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
693    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__weekday);
694  }
695};
696
697template <__fmt_char_type _CharT>
698struct _LIBCPP_TEMPLATE_VIS formatter<chrono::weekday_last, _CharT> : public __formatter_chrono<_CharT> {
699public:
700  using _Base = __formatter_chrono<_CharT>;
701
702  template <class _ParseContext>
703  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
704    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__weekday);
705  }
706};
707
708template <__fmt_char_type _CharT>
709struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_day, _CharT> : public __formatter_chrono<_CharT> {
710public:
711  using _Base = __formatter_chrono<_CharT>;
712
713  template <class _ParseContext>
714  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
715    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__month_day);
716  }
717};
718
719template <__fmt_char_type _CharT>
720struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_day_last, _CharT> : public __formatter_chrono<_CharT> {
721public:
722  using _Base = __formatter_chrono<_CharT>;
723
724  template <class _ParseContext>
725  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
726    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__month);
727  }
728};
729
730template <__fmt_char_type _CharT>
731struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_weekday, _CharT> : public __formatter_chrono<_CharT> {
732public:
733  using _Base = __formatter_chrono<_CharT>;
734
735  template <class _ParseContext>
736  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
737    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__month_weekday);
738  }
739};
740
741template <__fmt_char_type _CharT>
742struct _LIBCPP_TEMPLATE_VIS formatter<chrono::month_weekday_last, _CharT> : public __formatter_chrono<_CharT> {
743public:
744  using _Base = __formatter_chrono<_CharT>;
745
746  template <class _ParseContext>
747  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
748    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__month_weekday);
749  }
750};
751
752template <__fmt_char_type _CharT>
753struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month, _CharT> : public __formatter_chrono<_CharT> {
754public:
755  using _Base = __formatter_chrono<_CharT>;
756
757  template <class _ParseContext>
758  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
759    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__year_month);
760  }
761};
762
763template <__fmt_char_type _CharT>
764struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_day, _CharT> : public __formatter_chrono<_CharT> {
765public:
766  using _Base = __formatter_chrono<_CharT>;
767
768  template <class _ParseContext>
769  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
770    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__date);
771  }
772};
773
774template <__fmt_char_type _CharT>
775struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_day_last, _CharT> : public __formatter_chrono<_CharT> {
776public:
777  using _Base = __formatter_chrono<_CharT>;
778
779  template <class _ParseContext>
780  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
781    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__date);
782  }
783};
784
785template <__fmt_char_type _CharT>
786struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_weekday, _CharT> : public __formatter_chrono<_CharT> {
787public:
788  using _Base = __formatter_chrono<_CharT>;
789
790  template <class _ParseContext>
791  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
792    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__date);
793  }
794};
795
796template <__fmt_char_type _CharT>
797struct _LIBCPP_TEMPLATE_VIS formatter<chrono::year_month_weekday_last, _CharT> : public __formatter_chrono<_CharT> {
798public:
799  using _Base = __formatter_chrono<_CharT>;
800
801  template <class _ParseContext>
802  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
803    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__date);
804  }
805};
806
807template <class _Duration, __fmt_char_type _CharT>
808struct formatter<chrono::hh_mm_ss<_Duration>, _CharT> : public __formatter_chrono<_CharT> {
809public:
810  using _Base = __formatter_chrono<_CharT>;
811
812  template <class _ParseContext>
813  _LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
814    return _Base::__parse(__ctx, __format_spec::__fields_chrono, __format_spec::__flags::__time);
815  }
816};
817#endif // if _LIBCPP_STD_VER >= 20
818
819_LIBCPP_END_NAMESPACE_STD
820
821#endif //  _LIBCPP___CHRONO_FORMATTER_H
822