[PATCH] libstdc++: Constrain formatters for chrono types [PR119517]
Jonathan Wakely
jwakely@redhat.com
Fri Mar 28 20:33:34 GMT 2025
On 28/03/25 16:31 +0100, Tomasz Kamiński wrote:
>The formatters for chrono types defined the parse/format methods
>as accepting unconstrained types, this in combination with lack
>of constrain on _CharT lead to them falsy statisfying formattable
>requirements for any type used as character.
>
>This patch adjust the fromatter<T, CharT>::parse signature to:
> constexpr typename basic_format_parse_context<_CharT>::iterator
> parse(basic_format_parse_context<_CharT>& __pc);
>And formatter<T, CharT>::format to:
> template<typename _Out>
> typename basic_format_context<_Out, _CharT>::iterator
> format(const T& __t,
> basic_format_context<_Out, _CharT>& __fc) const;
>
>Furthermore we _CharT with __format::__char (char or wchar_t),
>
> PR libstdc++/119517
>
>libstdc++-v3/ChangeLog:
>
> * include/bits/chrono_io.h (formatter):
> Add __format::__char for _CharT and adjust parse and format
> method signatures.
> * testsuite/std/time/format/pr119517.cc: New test.
>---
>Testing on x86_64-linux, std/time/format tests passed.
>OK for trunk?
>
> libstdc++-v3/include/bits/chrono_io.h | 448 +++++++++---------
> .../testsuite/std/time/format/pr119517.cc | 44 ++
> 2 files changed, 262 insertions(+), 230 deletions(-)
> create mode 100644 libstdc++-v3/testsuite/std/time/format/pr119517.cc
>
>diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h
>index c55b651d049..3a5bc5695fb 100644
>--- a/libstdc++-v3/include/bits/chrono_io.h
>+++ b/libstdc++-v3/include/bits/chrono_io.h
>@@ -1785,277 +1785,272 @@ namespace __format
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::day, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Day); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Day); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::day& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::day& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::month, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Month); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Month); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::month& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::month& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::year, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Year); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Year); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::year& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::year& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::weekday, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Weekday); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Weekday); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::weekday& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::weekday& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::weekday_indexed, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Weekday); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Weekday); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::weekday_indexed& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::weekday_indexed& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::weekday_last, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Weekday); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Weekday); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::weekday_last& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::weekday_last& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::month_day, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Month|__format::_Day); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Month|__format::_Day); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::month_day& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::month_day& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::month_day_last, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Month|__format::_Day); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Month|__format::_Day); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::month_day_last& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::month_day_last& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::month_weekday, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Month|__format::_Weekday); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Month|__format::_Weekday); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::month_weekday& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::month_weekday& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::month_weekday_last, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Month|__format::_Weekday); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Month|__format::_Weekday); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
> format(const chrono::month_weekday_last& __t,
>- _FormatContext& __fc) const
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::year_month, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Year|__format::_Month); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Year|__format::_Month); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::year_month& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::year_month& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::year_month_day, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Date); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Date); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::year_month_day& __t, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::year_month_day& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::year_month_day_last, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Date); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Date); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
> format(const chrono::year_month_day_last& __t,
>- _FormatContext& __fc) const
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::year_month_weekday, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Date); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Date); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
> format(const chrono::year_month_weekday& __t,
>- _FormatContext& __fc) const
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::year_month_weekday_last, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_Date); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_Date); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
> format(const chrono::year_month_weekday_last& __t,
>- _FormatContext& __fc) const
>- { return _M_f._M_format(__t, __fc); }
>+ basic_format_context<_Out, _CharT>& __fc) const
>+ { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Rep, typename _Period, typename _CharT>
>+ template<typename _Rep, typename _Period, __format::__char _CharT>
> struct formatter<chrono::hh_mm_ss<chrono::duration<_Rep, _Period>>, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_TimeOfDay); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_TimeOfDay); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
> format(const chrono::hh_mm_ss<chrono::duration<_Rep, _Period>>& __t,
>- _FormatContext& __fc) const
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__t, __fc); }
>
> private:
>@@ -2063,34 +2058,34 @@ namespace __format
> };
>
> #if _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::sys_info, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ChronoParts{}); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ChronoParts{}); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::sys_info& __i, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::sys_info& __i,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__i, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _CharT>
>+ template<__format::__char _CharT>
> struct formatter<chrono::local_info, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ChronoParts{}); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ChronoParts{}); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::local_info& __i, _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::local_info& __i,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return _M_f._M_format(__i, __fc); }
>
> private:
>@@ -2098,25 +2093,24 @@ namespace __format
> };
> #endif
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::sys_time<_Duration>, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- {
>- auto __next = _M_f._M_parse(__pc, __format::_ZonedDateTime);
>- if constexpr (!__stream_insertable)
>- if (_M_f._M_spec._M_chrono_specs.empty())
>- __format::__invalid_chrono_spec(); // chrono-specs can't be empty
>- return __next;
>- }
>-
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::sys_time<_Duration>& __t,
>- _FormatContext& __fc) const
>- { return _M_f._M_format(__t, __fc); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ {
>+ auto __next = _M_f._M_parse(__pc, __format::_ZonedDateTime);
>+ if constexpr (!__stream_insertable)
>+ if (_M_f._M_spec._M_chrono_specs.empty())
>+ __format::__invalid_chrono_spec(); // chrono-specs can't be empty
>+ return __next;
>+ }
>+
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::sys_time<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
>+ { return _M_f._M_format(__t, __fc); }
>
> private:
> static constexpr bool __stream_insertable
>@@ -2126,19 +2120,18 @@ namespace __format
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::utc_time<_Duration>, _CharT>
> : __format::__formatter_chrono<_CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::utc_time<_Duration>& __t,
>- _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::utc_time<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> {
> // Adjust by removing leap seconds to get equivalent sys_time.
> // We can't just use clock_cast because we want to know if the time
>@@ -2161,19 +2154,18 @@ namespace __format
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::tai_time<_Duration>, _CharT>
> : __format::__formatter_chrono<_CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::tai_time<_Duration>& __t,
>- _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::tai_time<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> {
> // Convert to __local_time_fmt with abbrev "TAI" and offset 0s.
> // We use __local_time_fmt and not sys_time (as the standard implies)
>@@ -2193,19 +2185,18 @@ namespace __format
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::gps_time<_Duration>, _CharT>
> : __format::__formatter_chrono<_CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::gps_time<_Duration>& __t,
>- _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::gps_time<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> {
> // Convert to __local_time_fmt with abbrev "GPS" and offset 0s.
> // We use __local_time_fmt and not sys_time (as the standard implies)
>@@ -2225,72 +2216,69 @@ namespace __format
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::file_time<_Duration>, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::file_time<_Duration>& __t,
>- _FormatContext& __ctx) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::file_time<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> {
> using namespace chrono;
>- return _M_f._M_format(chrono::clock_cast<system_clock>(__t), __ctx);
>+ return _M_f._M_format(chrono::clock_cast<system_clock>(__t), __fc);
> }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::local_time<_Duration>, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_DateTime); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_DateTime); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::local_time<_Duration>& __t,
>- _FormatContext& __ctx) const
>- { return _M_f._M_format(__t, __ctx); }
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::local_time<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
>+ { return _M_f._M_format(__t, __fc); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::__detail::__local_time_fmt<_Duration>, _CharT>
> {
>- template<typename _ParseContext>
>- constexpr typename _ParseContext::iterator
>- parse(_ParseContext& __pc)
>- { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>+ constexpr typename basic_format_parse_context<_CharT>::iterator
>+ parse(basic_format_parse_context<_CharT>& __pc)
>+ { return _M_f._M_parse(__pc, __format::_ZonedDateTime); }
>
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::__detail::__local_time_fmt<_Duration>& __t,
>- _FormatContext& __ctx) const
>- { return _M_f._M_format(__t, __ctx, /* use %Z for {} */ true); }
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::__detail::__local_time_fmt<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
>+ { return _M_f._M_format(__t, __fc, /* use %Z for {} */ true); }
>
> private:
> __format::__formatter_chrono<_CharT> _M_f;
> };
>
> #if _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
>- template<typename _Duration, typename _TimeZonePtr, typename _CharT>
>+ template<typename _Duration, typename _TimeZonePtr, __format::__char _CharT>
> struct formatter<chrono::zoned_time<_Duration, _TimeZonePtr>, _CharT>
> : formatter<chrono::__detail::__local_time_fmt_for<_Duration>, _CharT>
> {
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::zoned_time<_Duration, _TimeZonePtr>& __tp,
>- _FormatContext& __ctx) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::zoned_time<_Duration, _TimeZonePtr>& __tp,
>+ basic_format_context<_Out, _CharT>& __fc) const
For zoned_time the standard does specify the signature of this
function, and it is supposed to look how I implemented it (see
[time.format] p19). I don't remember, but that's probably what
inspired me to do the same for all the other chrono formatters.
But despite that, I agree that it should be fixed.
> {
> using _Ltf = chrono::__detail::__local_time_fmt_for<_Duration>;
> using _Base = formatter<_Ltf, _CharT>;
>@@ -2298,20 +2286,20 @@ namespace __format
> const auto __lf = chrono::local_time_format(__tp.get_local_time(),
> &__info.abbrev,
> &__info.offset);
>- return _Base::format(__lf, __ctx);
>+ return _Base::format(__lf, __fc);
> }
> };
> #endif
>
> // Partial specialization needed for %c formatting of __utc_leap_second.
>- template<typename _Duration, typename _CharT>
>+ template<typename _Duration, __format::__char _CharT>
> struct formatter<chrono::__detail::__utc_leap_second<_Duration>, _CharT>
> : formatter<chrono::utc_time<_Duration>, _CharT>
> {
>- template<typename _FormatContext>
>- typename _FormatContext::iterator
>- format(const chrono::__detail::__utc_leap_second<_Duration>& __t,
>- _FormatContext& __fc) const
>+ template<typename _Out>
>+ typename basic_format_context<_Out, _CharT>::iterator
>+ format(const chrono::__detail::__utc_leap_second<_Duration>& __t,
>+ basic_format_context<_Out, _CharT>& __fc) const
> { return this->_M_f._M_format(__t, __fc); }
> };
>
>diff --git a/libstdc++-v3/testsuite/std/time/format/pr119517.cc b/libstdc++-v3/testsuite/std/time/format/pr119517.cc
>new file mode 100644
>index 00000000000..d1fc466eaab
>--- /dev/null
>+++ b/libstdc++-v3/testsuite/std/time/format/pr119517.cc
>@@ -0,0 +1,44 @@
>+// { dg-do compile { target c++23 } }
>+
>+#include <chrono>
>+#include <format>
>+#include <testsuite_hooks.h>
You don't need testsuite_hooks.h because this is a compile-only test
that doesn't use the runtime assertion VERIFY.
With that change, the patch is OK for trunk, thanks.
We should probably backport it to gcc-14 after a delay.
>+static_assert( std::formattable<std::chrono::weekday, char> );
>+static_assert( std::formattable<std::chrono::weekday, wchar_t> );
>+static_assert( !std::formattable<std::chrono::weekday, char16_t> );
>+
>+static_assert( std::formattable<std::chrono::sys_days, char> );
>+static_assert( std::formattable<std::chrono::sys_days, wchar_t> );
>+static_assert( !std::formattable<std::chrono::sys_days, char16_t> );
>+
>+static_assert( !std::formattable<std::chrono::seconds, int> );
>+
>+static_assert( !std::formattable<std::chrono::day, int> );
>+static_assert( !std::formattable<std::chrono::month, int> );
>+static_assert( !std::formattable<std::chrono::year, int> );
>+static_assert( !std::formattable<std::chrono::weekday, int> );
>+static_assert( !std::formattable<std::chrono::weekday_indexed, int> );
>+static_assert( !std::formattable<std::chrono::weekday_last, int> );
>+static_assert( !std::formattable<std::chrono::month_day, int> );
>+static_assert( !std::formattable<std::chrono::month_day_last, int> );
>+static_assert( !std::formattable<std::chrono::month_weekday, int> );
>+static_assert( !std::formattable<std::chrono::month_weekday_last, int> );
>+static_assert( !std::formattable<std::chrono::year_month_day, int> );
>+static_assert( !std::formattable<std::chrono::year_month_day_last, int> );
>+static_assert( !std::formattable<std::chrono::year_month_weekday, int> );
>+static_assert( !std::formattable<std::chrono::year_month_weekday_last, int> );
>+static_assert( !std::formattable<std::chrono::hh_mm_ss<std::chrono::seconds>, int> );
>+
>+static_assert( !std::formattable<std::chrono::sys_seconds, int> );
>+static_assert( !std::formattable<std::chrono::utc_seconds, int> );
>+static_assert( !std::formattable<std::chrono::tai_seconds, int> );
>+static_assert( !std::formattable<std::chrono::gps_seconds, int> );
>+static_assert( !std::formattable<std::chrono::local_seconds, int> );
>+static_assert( !std::formattable<std::chrono::file_time<std::chrono::seconds>, int> );
>+#if _GLIBCXX_USE_CXX11_ABI || ! _GLIBCXX_USE_DUAL_ABI
>+static_assert( !std::formattable<std::chrono::zoned_seconds, int> );
>+
>+static_assert( !std::formattable<std::chrono::sys_info, int> );
>+static_assert( !std::formattable<std::chrono::local_info, int> );
>+#endif
>--
>2.48.1
>
>
More information about the Libstdc++
mailing list