[PATCH] libstdc++: implement constexpr std::format
Tomasz Kaminski
tkaminsk@redhat.com
Thu Feb 26 16:07:01 GMT 2026
On Thu, Feb 26, 2026 at 4:48 PM Tomasz Kaminski <tkaminsk@redhat.com> wrote:
>
>
> On Thu, Feb 26, 2026 at 3:55 PM Ivan Lazaric <ivan.lazaric1@gmail.com>
> wrote:
>
>> libstdc++: partially implement constexpr std::format
>>
>> This patch partially implements constexpr formatting from P3391R2,
>> as such it does not define the __cpp_lib_constexpr_format feature-test
>> macro.
>>
>> This patch mostly adds `_GLIBCXX26_CONSTEXPR` to functions.
>>
>> Add `__format::__toupper` function that work in constexpr.
>> It is not fully general, but `<format>` doesn't need all uppercasing.
>>
>> Avoid using `_Ptr_sink` in constexpr in `__do_vformat_to`,
>> since it is a bit non-trivial to get it to work, and it is just an
>> optimization.
>>
>> Update some formatting tests to test constexpr as well,
>> and introduce a dedicated smoke test for constexpr formatting.
>>
>> This patch is missing:
>> * wide constexpr formatting
>> * constexpr to_{,w}string
>> * more constexpr tests
>>
>> libstdc++-v3/ChangeLog:
>>
>> * include/std/format:
>> Pepper in _GLIBCXX26_CONSTEXPR, replace memcpy with ranges::copy.
>> (__format::__toupper): Define.
>> (__format::__do_vformat_to):
>> Avoid using _Ptr_sink in constexpr.
>> * testsuite/std/format/constexpr.cc: New test.
>> * testsuite/std/format/debug.cc: Constexpr testing.
>> * testsuite/std/format/functions/format.cc: Constexpr testing.
>> * testsuite/std/format/functions/format_to.cc: Constexpr testing.
>> * testsuite/std/format/functions/size.cc: Constexpr testing.
>> * testsuite/std/format/ranges/format_kind.cc: Constexpr testing.
>> * testsuite/std/format/ranges/formatter.cc: Constexpr testing.
>> * testsuite/std/format/ranges/sequence.cc: Constexpr testing.
>> * testsuite/std/format/runtime_format.cc: Constexpr testing.
>> * testsuite/std/format/string.cc: Constexpr testing.
>> * testsuite/std/format/tuple.cc: Constexpr testing.
>>
>> Signed-off-by: Ivan Lazaric <ivan.lazaric1@gmail.com>
>> ---
>>
> Only comments on update, will do full review later.
>
>
>> Updates to patch:
>> Replaced __memcpy with ranges::copy
>> Simplified __toupper as a switch
>>
> I would rename it to __toupper_numeric, so it will be clear that
> it is not general purpose, and add handling of 'x' from prefix,
> if we ever use it on prefix value.
>
>> if (not) consteval replaced with std::is_constant_evaluated()
>> Rebased on top of your _M_access patch
>> Removed the version.{def,h} since this doesn't implement full paper
>>
> Please use no_stdname instad, that defines internal
> glibcxx_constexxpr_format,
> but not __cpp_lib one. That is the preferred approach in such a case.
>
> Cleaned up tests as suggested
>> Added a constexpr.cc test with c++26 target
>> Killed Counting_constexpr_sink, just going through _Ptr_sink
>>
>> Regarding formatting of nullptr:
>> basic_format_arg(nullptr) will store a `const void*` ,
>> so `format(nullptr)` will actually go through `formatter<const void*>`.
>>
> Makes sense, thanks.
>
>>
>> I've been testing with GLIBCXX_TESTSUITE_STDS=20,23,26,
>> two tests are failing in 26 now, both are testing compilation errors:
>> std/format/arguments/args_neg.cc
>>
> Haven't looked at this one yet.
>
We now say "in constexpr expansion of" instead of "required from here",
as we try to constant evluate the make_format_args. So I think we need
to accept both in tests.
> std/time/format/data_not_present_neg.cc
>>
> The second one is something we need to find way to address, as now
> we can evaluate following at compile time:
> std::format("{:bad}", 10);
> And in the test we use global variables:
> auto ym1 = std::format("{:%d}", 2024y/March); // { dg-error "call to
> consteval function" }
> For global variables we have try constexpr evaluation, so
> try to evaluate whole format call at compile time, and because
> it is constexpr now we try to do it. And that exception end up being
> propagated.
>
> However, the standard says that the format_string constructor should be
> ill-formed, beause it is consteval function, that is not core-constant
> expression.
> see this case https://eel.is/c++draft/format#fmt.string-3. Ie. following
> should
> not be able to work;
>
> consteval foo() {
> try {
> // should be ill-formed and not emit exception
> std::format("{:bad}", 10);
> }
> catch (std::format_error)
> { }
> }
>
> We could do try-catch inside cosntructor, but that way we will miss the
> actual
> content of the error. I was wondering about making the cosntructor simply
> noexcept
> so we will hit noexcept boundary at compile time. That should still print
> content
> of the error.
>
> Haven't yet investigated.
>>
>>
>> libstdc++-v3/include/std/format | 388 +++++++++++-------
>> .../testsuite/std/format/constexpr.cc | 126 ++++++
>> libstdc++-v3/testsuite/std/format/debug.cc | 105 +++--
>> .../testsuite/std/format/functions/format.cc | 265 +++++++-----
>> .../std/format/functions/format_to.cc | 63 ++-
>> .../testsuite/std/format/functions/size.cc | 24 +-
>> .../std/format/ranges/format_kind.cc | 15 +-
>> .../testsuite/std/format/ranges/formatter.cc | 45 +-
>> .../testsuite/std/format/ranges/sequence.cc | 73 +++-
>> .../testsuite/std/format/runtime_format.cc | 18 +-
>> libstdc++-v3/testsuite/std/format/string.cc | 230 +++++++----
>> libstdc++-v3/testsuite/std/format/tuple.cc | 78 +++-
>> 12 files changed, 967 insertions(+), 463 deletions(-)
>> create mode 100644 libstdc++-v3/testsuite/std/format/constexpr.cc
>>
>> diff --git a/libstdc++-v3/include/std/format
>> b/libstdc++-v3/include/std/format
>> index 4f0b0f377c6..b5670d0ec32 100644
>> --- a/libstdc++-v3/include/std/format
>> +++ b/libstdc++-v3/include/std/format
>> @@ -128,6 +128,7 @@ namespace __format
>> struct _Runtime_format_string
>> {
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> _Runtime_format_string(basic_string_view<_CharT> __s) noexcept
>> : _M_str(__s) { }
>>
>> @@ -173,6 +174,7 @@ namespace __format
>> basic_format_string(const _Tp& __s);
>>
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> basic_format_string(__format::_Runtime_format_string<_CharT> __s)
>> noexcept
>> : _M_str(__s._M_str)
>> { }
>> @@ -197,13 +199,13 @@ namespace __format
>>
>> #if __cpp_lib_format >= 202311L // >= C++26
>> [[__gnu__::__always_inline__]]
>> - inline __format::_Runtime_format_string<char>
>> + inline _GLIBCXX26_CONSTEXPR __format::_Runtime_format_string<char>
>> runtime_format(string_view __fmt) noexcept
>> { return __fmt; }
>>
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> [[__gnu__::__always_inline__]]
>> - inline __format::_Runtime_format_string<wchar_t>
>> + inline _GLIBCXX26_CONSTEXPR __format::_Runtime_format_string<wchar_t>
>> runtime_format(wstring_view __fmt) noexcept
>> { return __fmt; }
>> #endif
>> @@ -238,7 +240,7 @@ namespace __format
>>
>> /// @cond undocumented
>> [[noreturn]]
>> - inline void
>> + inline _GLIBCXX26_CONSTEXPR void
>> __throw_format_error(const char* __what)
>> { _GLIBCXX_THROW_OR_ABORT(format_error(__what)); }
>>
>> @@ -249,27 +251,27 @@ namespace __format
>> // XXX use named functions for each constexpr error?
>>
>> [[noreturn]]
>> - inline void
>> + inline _GLIBCXX26_CONSTEXPR void
>> __unmatched_left_brace_in_format_string()
>> { __throw_format_error("format error: unmatched '{' in format
>> string"); }
>>
>> [[noreturn]]
>> - inline void
>> + inline _GLIBCXX26_CONSTEXPR void
>> __unmatched_right_brace_in_format_string()
>> { __throw_format_error("format error: unmatched '}' in format
>> string"); }
>>
>> [[noreturn]]
>> - inline void
>> + inline _GLIBCXX26_CONSTEXPR void
>> __conflicting_indexing_in_format_string()
>> { __throw_format_error("format error: conflicting indexing style in
>> format string"); }
>>
>> [[noreturn]]
>> - inline void
>> + inline _GLIBCXX26_CONSTEXPR void
>> __invalid_arg_id_in_format_string()
>> { __throw_format_error("format error: invalid arg-id in format
>> string"); }
>>
>> [[noreturn]]
>> - inline void
>> + inline _GLIBCXX26_CONSTEXPR void
>> __failed_to_parse_format_spec()
>> { __throw_format_error("format error: failed to parse format-spec"); }
>>
>> @@ -517,7 +519,7 @@ namespace __format
>> using enum _WidthPrec;
>>
>> template<typename _Context>
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> __int_from_arg(const basic_format_arg<_Context>& __arg);
>>
>> constexpr bool __is_digit(char __c)
>> @@ -750,7 +752,7 @@ namespace __format
>> }
>>
>> template<typename _Context>
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> _M_get_width(_Context& __ctx) const
>> {
>> size_t __width = 0;
>> @@ -762,7 +764,7 @@ namespace __format
>> }
>>
>> template<typename _Context>
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> _M_get_precision(_Context& __ctx) const
>> {
>> size_t __prec = -1;
>> @@ -775,7 +777,7 @@ namespace __format
>> };
>>
>> template<typename _Int>
>> - inline char*
>> + inline _GLIBCXX26_CONSTEXPR char*
>> __put_sign(_Int __i, _Sign __sign, char* __dest) noexcept
>> {
>> if (__i < 0)
>> @@ -792,7 +794,7 @@ namespace __format
>> // Write STR to OUT (and do so efficiently if OUT is a _Sink_iter).
>> template<typename _Out, typename _CharT>
>> requires output_iterator<_Out, const _CharT&>
>> - inline _Out
>> + inline _GLIBCXX26_CONSTEXPR _Out
>> __write(_Out __out, basic_string_view<_CharT> __str)
>> {
>> if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
>> @@ -809,7 +811,7 @@ namespace __format
>> // Write STR to OUT with NFILL copies of FILL_CHAR specified by ALIGN.
>> // pre: __align != _Align_default
>> template<typename _Out, typename _CharT>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_padded(_Out __out, basic_string_view<_CharT> __str,
>> _Align __align, size_t __nfill, char32_t __fill_char)
>> {
>> @@ -883,7 +885,7 @@ namespace __format
>> // Write STR to OUT, with alignment and padding as determined by SPEC.
>> // pre: __spec._M_align != _Align_default || __align != _Align_default
>> template<typename _CharT, typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_padded_as_spec(basic_string_view<type_identity_t<_CharT>>
>> __str,
>> size_t __estimated_width,
>> basic_format_context<_Out, _CharT>& __fc,
>> @@ -905,7 +907,7 @@ namespace __format
>> }
>>
>> template<typename _CharT>
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> __truncate(basic_string_view<_CharT>& __s, size_t __prec)
>> {
>> if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
>> @@ -1049,7 +1051,7 @@ namespace __format
>>
>> using uint_least32_t = __UINT_LEAST32_TYPE__;
>> template<typename _Out, typename _CharT>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escape_seq(_Out __out, uint_least32_t __val,
>> basic_string_view<_CharT> __prefix)
>> {
>> @@ -1079,7 +1081,7 @@ namespace __format
>> }
>>
>> template<typename _Out, typename _CharT>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escape_seqs(_Out __out, basic_string_view<_CharT> __units)
>> {
>> using _UChar = make_unsigned_t<_CharT>;
>> @@ -1090,7 +1092,7 @@ namespace __format
>> }
>>
>> template<typename _Out, typename _CharT>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escaped_char(_Out __out, _CharT __c)
>> {
>> using _UChar = make_unsigned_t<_CharT>;
>> @@ -1116,7 +1118,7 @@ namespace __format
>> }
>>
>> template<typename _CharT, typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escaped_ascii(_Out __out,
>> basic_string_view<_CharT> __str,
>> _Term_char __term)
>> @@ -1146,7 +1148,7 @@ namespace __format
>> }
>>
>> template<typename _CharT, typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escaped_unicode_part(_Out __out, basic_string_view<_CharT>&
>> __str,
>> bool& __prev_esc, _Term_char __term)
>> {
>> @@ -1224,7 +1226,7 @@ namespace __format
>> }
>>
>> template<typename _CharT, typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escaped_unicode(_Out __out, basic_string_view<_CharT> __str,
>> _Term_char __term)
>> {
>> @@ -1236,7 +1238,7 @@ namespace __format
>> }
>>
>> template<typename _CharT, typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __write_escaped(_Out __out, basic_string_view<_CharT> __str,
>> _Term_char __term)
>> {
>> __out = __format::__write(__out,
>> _Escapes<_CharT>::_S_term(__term));
>> @@ -1257,12 +1259,14 @@ namespace __format
>> struct _Optional_locale
>> {
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> _Optional_locale() : _M_dummy(), _M_hasval(false) { }
>>
>> _Optional_locale(const locale& __loc) noexcept
>> : _M_loc(__loc), _M_hasval(true)
>> { }
>>
>> + _GLIBCXX26_CONSTEXPR
>> _Optional_locale(const _Optional_locale& __l) noexcept
>> : _M_dummy(), _M_hasval(__l._M_hasval)
>> {
>> @@ -1270,6 +1274,7 @@ namespace __format
>> std::construct_at(&_M_loc, __l._M_loc);
>> }
>>
>> + _GLIBCXX26_CONSTEXPR
>> _Optional_locale&
>> operator=(const _Optional_locale& __l) noexcept
>> {
>> @@ -1291,6 +1296,7 @@ namespace __format
>> return *this;
>> }
>>
>> + _GLIBCXX26_CONSTEXPR
>> ~_Optional_locale() { if (_M_hasval) _M_loc.~locale(); }
>>
>> _Optional_locale&
>> @@ -1317,7 +1323,8 @@ namespace __format
>> return _M_loc;
>> }
>>
>> - bool has_value() const noexcept { return _M_hasval; }
>> + _GLIBCXX26_CONSTEXPR bool
>> + has_value() const noexcept { return _M_hasval; }
>>
>> union {
>> char _M_dummy = '\0';
>> @@ -1391,7 +1398,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> format(basic_string_view<_CharT> __s,
>> basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -1408,7 +1415,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> _M_format_escaped(basic_string_view<_CharT> __s,
>> basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -1433,7 +1440,7 @@ namespace __format
>> #if __glibcxx_format_ranges // C++ >= 23 && HOSTED
>> template<ranges::input_range _Rg, typename _Out>
>> requires same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>,
>> _CharT>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> _M_format_range(_Rg&& __rg, basic_format_context<_Out, _CharT>&
>> __fc) const
>> {
>> using _Range = remove_reference_t<_Rg>;
>> @@ -1482,6 +1489,25 @@ namespace __format
>> _Spec<_CharT> _M_spec{};
>> };
>>
>> + [[__gnu__::__always_inline__]]
>> + constexpr char
>> + __toupper(char __c)
>> + {
>> + switch (__c)
>> + {
>> + case 'a': return 'A';
>> + case 'b': return 'B';
>> + case 'c': return 'C';
>> + case 'd': return 'D';
>> + case 'e': return 'E';
>> + case 'f': return 'F';
>> + case 'i': return 'I';
>> + case 'n': return 'N';
>> + case 'p': return 'P';
>> + default: return __c;
>> + }
>> + }
>> +
>> template<__char _CharT>
>> struct __formatter_int
>> {
>> @@ -1641,6 +1667,7 @@ namespace __format
>> }
>>
>> template<typename _Int, typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(_Int __i, basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -1689,11 +1716,7 @@ namespace __format
>> __res = to_chars(__start, __end, __u, 16);
>> if (_M_spec._M_type == _Pres_X)
>> for (auto __p = __start; __p != __res.ptr; ++__p)
>> -#if __has_builtin(__builtin_toupper)
>> - *__p = __builtin_toupper(*__p);
>> -#else
>> - *__p = std::toupper(*__p);
>> -#endif
>> + *__p = __format::__toupper(*__p);
>> break;
>> default:
>> __builtin_unreachable();
>> @@ -1702,8 +1725,7 @@ namespace __format
>> if (_M_spec._M_alt && __base_prefix.size())
>> {
>> __start -= __base_prefix.size();
>> - __builtin_memcpy(__start, __base_prefix.data(),
>> - __base_prefix.size());
>> + ranges::copy(__base_prefix, __start);
>> }
>> __start = __format::__put_sign(__i, _M_spec._M_sign, __start -
>> 1);
>>
>> @@ -1712,6 +1734,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(bool __i, basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -1742,6 +1765,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> _M_format_character(_CharT __c,
>> basic_format_context<_Out, _CharT>& __fc)
>> const
>> @@ -1773,7 +1797,7 @@ namespace __format
>> }
>>
>> template<typename _Int>
>> - static _CharT
>> + static _GLIBCXX26_CONSTEXPR _CharT
>> _S_to_character(_Int __i)
>> {
>> using _Traits = __gnu_cxx::__int_traits<_CharT>;
>> @@ -1794,6 +1818,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> _M_format_int(string_view __narrow_str, size_t __prefix_len,
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -2068,6 +2093,7 @@ namespace __format
>> }
>>
>> template<typename _Fp, typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(_Fp __v, basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -2197,7 +2223,7 @@ namespace __format
>> if (__upper)
>> {
>> for (char* __p = __start; __p != __res.ptr; ++__p)
>> - *__p = std::toupper(*__p);
>> + *__p = __format::__toupper(*__p);
>> }
>>
>> bool __have_sign = true;
>> @@ -2502,10 +2528,15 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(const void* __v, basic_format_context<_Out, _CharT>& __fc)
>> const
>> {
>> - auto __u = reinterpret_cast<__UINTPTR_TYPE__>(__v);
>> + // Treating nullptr specially
>> + // to enable constexpr formatting of nullptr_t.
>> + auto __u = __v
>> + ? reinterpret_cast<__UINTPTR_TYPE__>(__v)
>> + : (__UINTPTR_TYPE__)0;
>> char __buf[2 + sizeof(__v) * 2];
>> auto [__ptr, __ec] = std::to_chars(__buf + 2, std::end(__buf),
>> __u, 16);
>> @@ -2517,11 +2548,7 @@ namespace __format
>> {
>> __buf[1] = 'X';
>> for (auto __p = __buf + 2; __p != __ptr; ++__p)
>> -#if __has_builtin(__builtin_toupper)
>> - *__p = __builtin_toupper(*__p);
>> -#else
>> - *__p = std::toupper(*__p);
>> -#endif
>> + *__p = __format::__toupper(*__p);
>> }
>> #endif
>>
>> @@ -2590,6 +2617,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(_CharT __u, basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -2628,6 +2656,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, wchar_t>::iterator
>> format(char __u, basic_format_context<_Out, wchar_t>& __fc) const
>> {
>> @@ -2663,6 +2692,7 @@ namespace __format
>>
>> template<typename _Out>
>> [[__gnu__::__nonnull__]]
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(_CharT* __u, basic_format_context<_Out, _CharT>& __fc)
>> const
>> { return _M_f.format(__u, __fc); }
>> @@ -2692,6 +2722,7 @@ namespace __format
>>
>> template<typename _Out>
>> [[__gnu__::__nonnull__]]
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(const _CharT* __u,
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -2722,6 +2753,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(const _CharT (&__u)[_Nm],
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -2751,6 +2783,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, char>::iterator
>> format(const basic_string<char, _Traits, _Alloc>& __u,
>> basic_format_context<_Out, char>& __fc) const
>> @@ -2783,6 +2816,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, wchar_t>::iterator
>> format(const basic_string<wchar_t, _Traits, _Alloc>& __u,
>> basic_format_context<_Out, wchar_t>& __fc) const
>> @@ -2816,6 +2850,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, char>::iterator
>> format(basic_string_view<char, _Traits> __u,
>> basic_format_context<_Out, char>& __fc) const
>> @@ -2848,6 +2883,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, wchar_t>::iterator
>> format(basic_string_view<wchar_t, _Traits> __u,
>> basic_format_context<_Out, wchar_t>& __fc) const
>> @@ -2911,6 +2947,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(_Tp __u, basic_format_context<_Out, _CharT>& __fc) const
>> { return _M_f.format(__u, __fc); }
>> @@ -3122,6 +3159,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(const void* __v, basic_format_context<_Out, _CharT>& __fc)
>> const
>> { return _M_f.format(__v, __fc); }
>> @@ -3147,6 +3185,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(void* __v, basic_format_context<_Out, _CharT>& __fc) const
>> { return _M_f.format(__v, __fc); }
>> @@ -3172,6 +3211,7 @@ namespace __format
>> { return _M_f.parse(__pc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(nullptr_t, basic_format_context<_Out, _CharT>& __fc) const
>> { return _M_f.format(nullptr, __fc); }
>> @@ -3316,11 +3356,11 @@ namespace __format
>> constexpr _Sink_iter
>> operator++(int) { return *this; }
>>
>> - auto
>> + _GLIBCXX26_CONSTEXPR auto
>> _M_reserve(size_t __n) const
>> { return _M_sink->_M_reserve(__n); }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_discarding() const
>> { return _M_sink->_M_discarding(); }
>> };
>> @@ -3352,7 +3392,7 @@ namespace __format
>>
>> // The portion of the span that has been written to.
>> [[__gnu__::__always_inline__]]
>> - span<_CharT>
>> + _GLIBCXX26_CONSTEXPR span<_CharT>
>> _M_used() const noexcept
>> { return _M_span.first(_M_next - _M_span.begin()); }
>>
>> @@ -3369,7 +3409,7 @@ namespace __format
>> { _M_next = _M_span.begin(); }
>>
>> // Replace the current output range.
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_reset(span<_CharT> __s, size_t __pos = 0) noexcept
>> {
>> _M_span = __s;
>> @@ -3409,11 +3449,14 @@ namespace __format
>> struct _Reservation
>> {
>> // True if the reservation was successful, false otherwise.
>> + _GLIBCXX26_CONSTEXPR
>> explicit operator bool() const noexcept { return _M_sink; }
>> // A pointer to write directly to the sink.
>> - _CharT* get() const noexcept { return
>> _M_sink->_M_next.operator->(); }
>> + _GLIBCXX26_CONSTEXPR _CharT*
>> + get() const noexcept { return _M_sink->_M_next.operator->(); }
>> // Add n to the _M_next iterator for the sink.
>> - void _M_bump(size_t __n) { _M_sink->_M_bump(__n); }
>> + _GLIBCXX26_CONSTEXPR void
>> + _M_bump(size_t __n) { _M_sink->_M_bump(__n); }
>> _Sink* _M_sink;
>> };
>>
>> @@ -3421,7 +3464,7 @@ namespace __format
>> // If anything is written to the reservation then there must be a
>> call
>> // to _M_bump(N2) before any call to another member function of
>> *this,
>> // where N2 is the number of characters written.
>> - virtual _Reservation
>> + _GLIBCXX26_CONSTEXPR virtual _Reservation
>> _M_reserve(size_t __n)
>> {
>> if (__n <= _M_unused().size())
>> @@ -3438,12 +3481,12 @@ namespace __format
>>
>> // Update the next output position after writing directly to the
>> sink.
>> // pre: no calls to _M_write or _M_overflow since _M_reserve.
>> - virtual void
>> + _GLIBCXX26_CONSTEXPR virtual void
>> _M_bump(size_t __n)
>> { _M_next += __n; }
>>
>> // Returns true if the _Sink is discarding incoming characters.
>> - virtual bool
>> + _GLIBCXX26_CONSTEXPR virtual bool
>> _M_discarding() const
>> { return false; }
>>
>> @@ -3461,7 +3504,7 @@ namespace __format
>> template<typename _CharT>
>> class _Fixedbuf_sink final : public _Sink<_CharT>
>> {
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_overflow() override
>> {
>> __glibcxx_assert(false);
>> @@ -3509,7 +3552,7 @@ namespace __format
>> _Seq _M_seq;
>> protected:
>> // Transfer buffer contents to the sequence, so buffer can be
>> refilled.
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_overflow() override
>> {
>> auto __s = this->_M_used();
>> @@ -3528,7 +3571,7 @@ namespace __format
>> this->_M_rewind();
>> }
>>
>> - typename _Sink<_CharT>::_Reservation
>> + _GLIBCXX26_CONSTEXPR typename _Sink<_CharT>::_Reservation
>> _M_reserve(size_t __n) override
>> {
>> // We might already have n characters available in
>> this->_M_unused(),
>> @@ -3564,7 +3607,7 @@ namespace __format
>> return _Sink<_CharT>::_M_reserve(__n);
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_bump(size_t __n) override
>> {
>> if constexpr (__is_specialization_of<_Seq, basic_string>
>> @@ -3579,7 +3622,8 @@ namespace __format
>> }
>> }
>>
>> - void _M_trim(span<const _CharT> __s)
>> + _GLIBCXX26_CONSTEXPR void
>> + _M_trim(span<const _CharT> __s)
>> requires __is_specialization_of<_Seq, basic_string>
>> {
>> _GLIBCXX_DEBUG_ASSERT(__s.data() == this->_M_buf
>> @@ -3595,16 +3639,18 @@ namespace __format
>> // to _M_buf if it overflows? Or even do that for all unused
>> capacity?
>>
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> _Seq_sink() noexcept(is_nothrow_default_constructible_v<_Seq>)
>> { }
>>
>> + _GLIBCXX26_CONSTEXPR
>> _Seq_sink(_Seq&& __s)
>> noexcept(is_nothrow_move_constructible_v<_Seq>)
>> : _M_seq(std::move(__s))
>> { }
>>
>> using _Sink<_CharT>::out;
>>
>> - _Seq
>> + _GLIBCXX26_CONSTEXPR _Seq
>> get() &&
>> {
>> if (this->_M_used().size() != 0)
>> @@ -3614,7 +3660,7 @@ namespace __format
>>
>> // A writable span that views everything written to the sink.
>> // Will be either a view over _M_seq or the used part of _M_buf.
>> - span<_CharT>
>> + _GLIBCXX26_CONSTEXPR span<_CharT>
>> _M_span()
>> {
>> auto __s = this->_M_used();
>> @@ -3627,7 +3673,7 @@ namespace __format
>> return __s;
>> }
>>
>> - basic_string_view<_CharT>
>> + _GLIBCXX26_CONSTEXPR basic_string_view<_CharT>
>> view()
>> {
>> auto __span = _M_span();
>> @@ -3652,7 +3698,7 @@ namespace __format
>> protected:
>> size_t _M_count = 0;
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_overflow() override
>> {
>> auto __s = this->_M_used();
>> @@ -3672,7 +3718,7 @@ namespace __format
>> _M_count += __s.size();
>> }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_discarding() const override
>> {
>> // format_to_n return total number of characters, that would be
>> written,
>> @@ -3682,14 +3728,14 @@ namespace __format
>>
>> public:
>> [[__gnu__::__always_inline__]]
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Iter_sink(_OutIter __out, iter_difference_t<_OutIter> __max = -1)
>> : _M_out(std::move(__out)), _M_max(__max)
>> { }
>>
>> using _Sink<_CharT>::out;
>>
>> - format_to_n_result<_OutIter>
>> + _GLIBCXX26_CONSTEXPR format_to_n_result<_OutIter>
>> _M_finish() &&
>> {
>> if (this->_M_used().size() != 0)
>> @@ -3718,7 +3764,7 @@ namespace __format
>> _CharT _M_buf[64]; // Write here after outputting _M_max
>> characters.
>>
>> protected:
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_overflow() override
>> {
>> if (this->_M_unused().size() != 0)
>> @@ -3742,7 +3788,7 @@ namespace __format
>> }
>> }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_discarding() const override
>> {
>> // format_to_n return total number of characters, that would be
>> written,
>> @@ -3750,7 +3796,7 @@ namespace __format
>> return false;
>> }
>>
>> - typename _Sink<_CharT>::_Reservation
>> + _GLIBCXX26_CONSTEXPR typename _Sink<_CharT>::_Reservation
>> _M_reserve(size_t __n) final
>> {
>> auto __avail = this->_M_unused();
>> @@ -3767,7 +3813,7 @@ namespace __format
>>
>> private:
>> template<typename _IterDifference>
>> - static size_t
>> + static _GLIBCXX26_CONSTEXPR size_t
>> _S_trim_max(_IterDifference __max)
>> {
>> if (__max < 0)
>> @@ -3780,7 +3826,7 @@ namespace __format
>> }
>>
>> [[__gnu__::__always_inline__]]
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_rebuf(_CharT* __ptr, size_t __total, size_t __inuse = 0)
>> {
>> std::span<_CharT> __span(__ptr, __total);
>> @@ -3788,7 +3834,7 @@ namespace __format
>> }
>>
>> public:
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Ptr_sink(_CharT* __ptr, size_t __n = _S_no_limit) noexcept
>> : _Sink<_CharT>(_M_buf), _M_max(__n)
>> {
>> @@ -3813,13 +3859,13 @@ namespace __format
>> }
>>
>> template<contiguous_iterator _OutIter>
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Ptr_sink(_OutIter __out, iter_difference_t<_OutIter> __n = -1)
>> : _Ptr_sink(std::to_address(__out), _S_trim_max(__n))
>> { }
>>
>> template<contiguous_iterator _OutIter>
>> - format_to_n_result<_OutIter>
>> + _GLIBCXX26_CONSTEXPR format_to_n_result<_OutIter>
>> _M_finish(_OutIter __first) const
>> {
>> auto __s = this->_M_used();
>> @@ -3861,12 +3907,12 @@ namespace __format
>> size_t _M_printwidth;
>>
>> [[__gnu__::__always_inline__]]
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_ignoring() const
>> { return _M_printwidth >= _M_maxwidth; }
>>
>> [[__gnu__::__always_inline__]]
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_buffering() const
>> {
>> if (_M_printwidth < _M_padwidth)
>> @@ -3876,7 +3922,7 @@ namespace __format
>> return false;
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_sync_discarding()
>> {
>> if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
>> @@ -3884,7 +3930,7 @@ namespace __format
>> _M_maxwidth = _M_printwidth;
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_flush()
>> {
>> span<_CharT> __new = this->_M_used();
>> @@ -3894,7 +3940,7 @@ namespace __format
>> this->_M_rewind();
>> }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_force_update()
>> {
>> auto __str = this->view();
>> @@ -3922,7 +3968,7 @@ namespace __format
>> return false;
>> }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_update(size_t __new)
>> {
>> _M_printwidth += __new;
>> @@ -3932,7 +3978,7 @@ namespace __format
>> return true;
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_overflow() override
>> {
>> // Ignore characters in buffer, and override it.
>> @@ -3947,11 +3993,11 @@ namespace __format
>> _Str_sink<_CharT>::_M_overflow();
>> }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_discarding() const override
>> { return _M_ignoring(); }
>>
>> - typename _Sink<_CharT>::_Reservation
>> + _GLIBCXX26_CONSTEXPR typename _Sink<_CharT>::_Reservation
>> _M_reserve(size_t __n) override
>> {
>> // Ignore characters in buffer, if any.
>> @@ -3970,7 +4016,7 @@ namespace __format
>> return _Sink<_CharT>::_M_reserve(__n);
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_bump(size_t __n) override
>> {
>> // Ignore the written characters.
>> @@ -3985,19 +4031,19 @@ namespace __format
>>
>> public:
>> [[__gnu__::__always_inline__]]
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Padding_sink(_Out __out, size_t __padwidth, size_t __maxwidth)
>> : _M_padwidth(__padwidth), _M_maxwidth(__maxwidth),
>> _M_out(std::move(__out)), _M_printwidth(0)
>> { _M_sync_discarding(); }
>>
>> [[__gnu__::__always_inline__]]
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Padding_sink(_Out __out, size_t __padwidth)
>> : _Padding_sink(std::move(__out), __padwidth, (size_t)-1)
>> { }
>>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> _M_finish(_Align __align, char32_t __fill_char)
>> {
>> // Handle any characters in the buffer.
>> @@ -4036,14 +4082,14 @@ namespace __format
>> unsigned _M_prev_escape : 1;
>> unsigned _M_out_discards : 1;
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_sync_discarding()
>> {
>> if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
>> _M_out_discards = _M_out._M_discarding();
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_write()
>> {
>> span<_CharT> __bytes = this->_M_used();
>> @@ -4069,7 +4115,7 @@ namespace __format
>> _M_sync_discarding();
>> }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_overflow() override
>> {
>> if (_M_out_discards)
>> @@ -4078,13 +4124,13 @@ namespace __format
>> _M_write();
>> }
>>
>> - bool
>> + _GLIBCXX26_CONSTEXPR bool
>> _M_discarding() const override
>> { return _M_out_discards; }
>>
>> public:
>> [[__gnu__::__always_inline__]]
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Escaping_sink(_Out __out, _Term_char __term)
>> : _M_out(std::move(__out)), _M_term(__term),
>> _M_prev_escape(true), _M_out_discards(false)
>> @@ -4093,7 +4139,7 @@ namespace __format
>> _M_sync_discarding();
>> }
>>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> _M_finish()
>> {
>> if (_M_out_discards)
>> @@ -4141,7 +4187,7 @@ namespace __format
>> const _Tp, _Tp>;
>>
>> template<typename _Tq>
>> - static void
>> + static _GLIBCXX26_CONSTEXPR void
>> _S_format(basic_format_parse_context<_CharT>& __parse_ctx,
>> _Context& __format_ctx, const void* __ptr)
>> {
>> @@ -4154,7 +4200,7 @@ namespace __format
>>
>> template<typename _Tp>
>> requires (!is_same_v<remove_cv_t<_Tp>, _Handle>)
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> _Handle(_Tp& __val) noexcept
>> : _M_ptr(__builtin_addressof(__val))
>> , _M_func(&_S_format<__maybe_const_t<_Tp>>)
>> @@ -4169,7 +4215,7 @@ namespace __format
>> _Handle& operator=(const _Handle&) = default;
>>
>> [[__gnu__::__always_inline__]]
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> format(basic_format_parse_context<_CharT>& __pc, _Context& __fc)
>> const
>> { _M_func(__pc, __fc, this->_M_ptr); }
>>
>> @@ -4226,10 +4272,12 @@ namespace __format
>> };
>>
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> _Arg_value() : _M_none() { }
>>
>> #if 0
>> template<typename _Tp>
>> + _GLIBCXX26_CONSTEXPR
>> _Arg_value(in_place_type_t<_Tp>, _Tp __val)
>> { _S_get<_Tp>() = __val; }
>> #endif
>> @@ -4238,7 +4286,7 @@ namespace __format
>> // Value of second argument (if provided), is assigned to that
>> member.
>> template<typename _Tp, typename _Self, typename... _Value>
>> [[__gnu__::__always_inline__]]
>> - static auto&
>> + static _GLIBCXX26_CONSTEXPR auto&
>> _S_access(_Self& __u, _Value... __value) noexcept
>> {
>> static_assert(sizeof...(_Value) <= 1);
>> @@ -4302,23 +4350,24 @@ namespace __format
>> else if constexpr (is_same_v<_Tp, _Handle<_Context>>)
>> return (__u._M_handle = ... = __value);
>> // Otherwise, ill-formed.
>> + __builtin_unreachable();
>> }
>>
>> template<typename _Tp>
>> [[__gnu__::__always_inline__]]
>> - auto&
>> + _GLIBCXX26_CONSTEXPR auto&
>> _M_get() noexcept
>> { return _S_access<_Tp>(*this); }
>>
>> template<typename _Tp>
>> [[__gnu__::__always_inline__]]
>> - const auto&
>> + _GLIBCXX26_CONSTEXPR const auto&
>> _M_get() const noexcept
>> { return _S_access<_Tp>(*this); }
>>
>> template<typename _Tp>
>> [[__gnu__::__always_inline__]]
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_set(_Tp __v) noexcept
>> {
>> if constexpr (is_same_v<_Tp, basic_string_view<_CharT>>)
>> @@ -4335,7 +4384,8 @@ namespace __format
>> class _Arg_store;
>>
>> template<typename _Visitor, typename _Ctx>
>> - decltype(auto) __visit_format_arg(_Visitor&&,
>> basic_format_arg<_Ctx>);
>> + _GLIBCXX26_CONSTEXPR decltype(auto)
>> + __visit_format_arg(_Visitor&&, basic_format_arg<_Ctx>);
>>
>> template<typename _Ch, typename _Tp>
>> consteval _Arg_t
>> @@ -4351,20 +4401,21 @@ namespace __format
>> public:
>> using handle = __format::_Handle<_Context>;
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> basic_format_arg() noexcept : _M_type(__format::_Arg_none) { }
>>
>> [[nodiscard,__gnu__::__always_inline__]]
>> - explicit operator bool() const noexcept
>> + explicit _GLIBCXX26_CONSTEXPR operator bool() const noexcept
>> { return _M_type != __format::_Arg_none; }
>>
>> #if __cpp_lib_format >= 202306L // >= C++26
>> template<typename _Visitor>
>> - decltype(auto)
>> + _GLIBCXX26_CONSTEXPR decltype(auto)
>> visit(this basic_format_arg __arg, _Visitor&& __vis)
>> { return __arg._M_visit_user(std::forward<_Visitor>(__vis),
>> __arg._M_type); }
>>
>> template<typename _Res, typename _Visitor>
>> - _Res
>> + _GLIBCXX26_CONSTEXPR _Res
>> visit(this basic_format_arg __arg, _Visitor&& __vis)
>> { return __arg._M_visit_user(std::forward<_Visitor>(__vis),
>> __arg._M_type); }
>> #endif
>> @@ -4541,7 +4592,7 @@ namespace __format
>> }
>>
>> template<typename _Tp>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_set(_Tp __v) noexcept
>> {
>> _M_type = _S_to_enum<_Tp>();
>> @@ -4550,7 +4601,7 @@ namespace __format
>>
>> template<typename _Tp>
>> requires __format::__formattable_with<_Tp, _Context>
>> - explicit
>> + _GLIBCXX26_CONSTEXPR explicit
>> basic_format_arg(_Tp& __v) noexcept
>> {
>> using _Td = _Normalize<_Tp>;
>> @@ -4564,15 +4615,15 @@ namespace __format
>> }
>>
>> template<typename _Ctx, typename... _Argz>
>> - friend auto
>> + friend _GLIBCXX26_CONSTEXPR auto
>> make_format_args(_Argz&...) noexcept;
>>
>> template<typename _Visitor, typename _Ctx>
>> - friend decltype(auto)
>> + friend _GLIBCXX26_CONSTEXPR decltype(auto)
>> visit_format_arg(_Visitor&& __vis, basic_format_arg<_Ctx>);
>>
>> template<typename _Visitor, typename _Ctx>
>> - friend decltype(auto)
>> + friend _GLIBCXX26_CONSTEXPR decltype(auto)
>> __format::__visit_format_arg(_Visitor&&, basic_format_arg<_Ctx>);
>>
>> template<typename _Ch, typename _Tp>
>> @@ -4580,7 +4631,7 @@ namespace __format
>> __format::__to_arg_t_enum() noexcept;
>>
>> template<typename _Visitor>
>> - decltype(auto)
>> + _GLIBCXX26_CONSTEXPR decltype(auto)
>> _M_visit(_Visitor&& __vis, __format::_Arg_t __type)
>> {
>> using namespace __format;
>> @@ -4655,7 +4706,7 @@ namespace __format
>> }
>>
>> template<typename _Visitor>
>> - decltype(auto)
>> + _GLIBCXX26_CONSTEXPR decltype(auto)
>> _M_visit_user(_Visitor&& __vis, __format::_Arg_t __type)
>> {
>> return _M_visit([&__vis]<typename _Tp>(_Tp& __val) ->
>> decltype(auto)
>> @@ -4679,7 +4730,7 @@ namespace __format
>>
>> template<typename _Visitor, typename _Context>
>> _GLIBCXX26_DEPRECATED_SUGGEST("std::basic_format_arg::visit")
>> - inline decltype(auto)
>> + inline _GLIBCXX26_CONSTEXPR decltype(auto)
>> visit_format_arg(_Visitor&& __vis, basic_format_arg<_Context> __arg)
>> {
>> return __arg._M_visit_user(std::forward<_Visitor>(__vis),
>> __arg._M_type);
>> @@ -4689,7 +4740,7 @@ namespace __format
>> namespace __format
>> {
>> template<typename _Visitor, typename _Ctx>
>> - inline decltype(auto)
>> + inline _GLIBCXX26_CONSTEXPR decltype(auto)
>> __visit_format_arg(_Visitor&& __vis, basic_format_arg<_Ctx> __arg)
>> {
>> return __arg._M_visit(std::forward<_Visitor>(__vis),
>> __arg._M_type);
>> @@ -4698,7 +4749,7 @@ namespace __format
>> struct _WidthPrecVisitor
>> {
>> template<typename _Tp>
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> operator()(_Tp& __arg) const
>> {
>> if constexpr (is_same_v<_Tp, monostate>)
>> @@ -4724,7 +4775,7 @@ namespace __format
>> #pragma GCC diagnostic push
>> #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
>> template<typename _Context>
>> - inline size_t
>> + inline _GLIBCXX26_CONSTEXPR size_t
>> __int_from_arg(const basic_format_arg<_Context>& __arg)
>> { return __format::__visit_format_arg(_WidthPrecVisitor(), __arg); }
>>
>> @@ -4772,11 +4823,11 @@ namespace __format
>> const _Format_arg* _M_args; // Active when _M_packed_size
>> == 0
>> };
>>
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> _M_size() const noexcept
>> { return _M_packed_size ? _M_packed_size : _M_unpacked_size; }
>>
>> - typename __format::_Arg_t
>> + _GLIBCXX26_CONSTEXPR typename __format::_Arg_t
>> _M_type(size_t __i) const noexcept
>> {
>> uint64_t __t = _M_unpacked_size >> (__i * _S_packed_type_bits);
>> @@ -4784,7 +4835,7 @@ namespace __format
>> }
>>
>> template<typename _Ctx, typename... _Args>
>> - friend auto
>> + friend _GLIBCXX26_CONSTEXPR auto
>> make_format_args(_Args&...) noexcept;
>>
>> // An array of _Arg_t enums corresponding to _Args...
>> @@ -4795,10 +4846,11 @@ namespace __format
>>
>> public:
>> template<typename... _Args>
>> + _GLIBCXX26_CONSTEXPR
>> basic_format_args(const _Store<_Args...>& __store) noexcept;
>>
>> [[nodiscard,__gnu__::__always_inline__]]
>> - basic_format_arg<_Context>
>> + _GLIBCXX26_CONSTEXPR basic_format_arg<_Context>
>> get(size_t __i) const noexcept
>> {
>> basic_format_arg<_Context> __arg;
>> @@ -4820,7 +4872,7 @@ namespace __format
>> -> basic_format_args<_Context>;
>>
>> template<typename _Context, typename... _Args>
>> - auto
>> + _GLIBCXX26_CONSTEXPR auto
>> make_format_args(_Args&... __fmt_args) noexcept;
>>
>> // An array of type-erased formatting arguments.
>> @@ -4830,7 +4882,7 @@ namespace __format
>> friend std::basic_format_args<_Context>;
>>
>> template<typename _Ctx, typename... _Argz>
>> - friend auto std::
>> + friend _GLIBCXX26_CONSTEXPR auto std::
>> #if _GLIBCXX_INLINE_VERSION
>> __8:: // Needed for PR c++/59256
>> #endif
>> @@ -4849,7 +4901,7 @@ namespace __format
>> _Element_t _M_args[sizeof...(_Args)];
>>
>> template<typename _Tp>
>> - static _Element_t
>> + static _GLIBCXX26_CONSTEXPR _Element_t
>> _S_make_elt(_Tp& __v)
>> {
>> using _Tq = remove_const_t<_Tp>;
>> @@ -4875,6 +4927,7 @@ namespace __format
>> template<typename... _Tp>
>> requires (sizeof...(_Tp) == sizeof...(_Args))
>> [[__gnu__::__always_inline__]]
>> + _GLIBCXX26_CONSTEXPR
>> _Arg_store(_Tp&... __a) noexcept
>> : _M_args{_S_make_elt(__a)...}
>> { }
>> @@ -4886,7 +4939,7 @@ namespace __format
>>
>> template<typename _Context>
>> template<typename... _Args>
>> - inline
>> + inline _GLIBCXX26_CONSTEXPR
>> basic_format_args<_Context>::
>> basic_format_args(const _Store<_Args...>& __store) noexcept
>> {
>> @@ -4920,7 +4973,7 @@ namespace __format
>> /// Capture formatting arguments for use by `std::vformat`.
>> template<typename _Context = format_context, typename... _Args>
>> [[nodiscard,__gnu__::__always_inline__]]
>> - inline auto
>> + inline _GLIBCXX26_CONSTEXPR auto
>> make_format_args(_Args&... __fmt_args) noexcept
>> {
>> using _Fmt_arg = basic_format_arg<_Context>;
>> @@ -4933,7 +4986,7 @@ namespace __format
>> /// Capture formatting arguments for use by `std::vformat` (for wide
>> output).
>> template<typename... _Args>
>> [[nodiscard,__gnu__::__always_inline__]]
>> - inline auto
>> + inline _GLIBCXX26_CONSTEXPR auto
>> make_wformat_args(_Args&... __args) noexcept
>> { return std::make_format_args<wformat_context>(__args...); }
>> #endif
>> @@ -4942,13 +4995,13 @@ namespace __format
>> namespace __format
>> {
>> template<typename _Out, typename _CharT, typename _Context>
>> - _Out
>> + _GLIBCXX26_CONSTEXPR _Out
>> __do_vformat_to(_Out, basic_string_view<_CharT>,
>> const basic_format_args<_Context>&,
>> const locale* = nullptr);
>>
>> template<typename _Out, typename _CharT>
>> - format_to_n_result<_Out>
>> + _GLIBCXX26_CONSTEXPR format_to_n_result<_Out>
>> __do_vformat_to_n(_Out, iter_difference_t<_Out>,
>> basic_string_view<_CharT>,
>> const type_identity_t<
>> @@ -4982,11 +5035,13 @@ namespace __format
>> _Out _M_out;
>> __format::_Optional_locale _M_loc;
>>
>> + _GLIBCXX26_CONSTEXPR
>> basic_format_context(basic_format_args<basic_format_context>
>> __args,
>> _Out __out)
>> : _M_args(__args), _M_out(std::move(__out))
>> { }
>>
>> + _GLIBCXX26_CONSTEXPR
>> basic_format_context(basic_format_args<basic_format_context>
>> __args,
>> _Out __out, const std::locale& __loc)
>> : _M_args(__args), _M_out(std::move(__out)), _M_loc(__loc)
>> @@ -4999,7 +5054,7 @@ namespace __format
>> basic_format_context& operator=(const basic_format_context&) =
>> delete;
>>
>> template<typename _Out2, typename _CharT2, typename _Context2>
>> - friend _Out2
>> + friend _GLIBCXX26_CONSTEXPR _Out2
>> __format::__do_vformat_to(_Out2, basic_string_view<_CharT2>,
>> const basic_format_args<_Context2>&,
>> const locale*);
>> @@ -5015,7 +5070,7 @@ namespace __format
>> using formatter_type = formatter<_Tp, _CharT>;
>>
>> [[nodiscard]]
>> - basic_format_arg<basic_format_context>
>> + _GLIBCXX26_CONSTEXPR basic_format_arg<basic_format_context>
>> arg(size_t __id) const noexcept
>> { return _M_args.get(__id); }
>>
>> @@ -5023,9 +5078,11 @@ namespace __format
>> std::locale locale() { return _M_loc.value(); }
>>
>> [[nodiscard]]
>> - iterator out() { return std::move(_M_out); }
>> + _GLIBCXX26_CONSTEXPR iterator
>> + out() { return std::move(_M_out); }
>>
>> - void advance_to(iterator __it) { _M_out = std::move(__it); }
>> + _GLIBCXX26_CONSTEXPR void
>> + advance_to(iterator __it) { _M_out = std::move(__it); }
>> };
>>
>>
>> @@ -5164,6 +5221,7 @@ namespace __format
>> class _Formatting_scanner : public _Scanner<_CharT>
>> {
>> public:
>> + _GLIBCXX26_CONSTEXPR
>> _Formatting_scanner(basic_format_context<_Out, _CharT>& __fc,
>> basic_string_view<_CharT> __str)
>> : _Scanner<_CharT>(__str), _M_fc(__fc)
>> @@ -5271,7 +5329,7 @@ namespace __format
>> };
>>
>> template<typename _Out, typename _CharT, typename _Context>
>> - inline _Out
>> + inline _GLIBCXX26_CONSTEXPR _Out
>> __do_vformat_to(_Out __out, basic_string_view<_CharT> __fmt,
>> const basic_format_args<_Context>& __args,
>> const locale* __loc)
>> @@ -5291,7 +5349,7 @@ namespace __format
>> const char* __chars[] = { "false", "true" };
>> if (auto __res = __out._M_reserve(__len))
>> {
>> - __builtin_memcpy(__res.get(), __chars[__arg],
>> __len);
>> + ranges::copy_n(__chars[__arg], __len,
>> __res.get());
>> __res._M_bump(__len);
>> __done = true;
>> }
>> @@ -5329,7 +5387,7 @@ namespace __format
>> string_view __sv = __arg;
>> if (auto __res = __out._M_reserve(__sv.size()))
>> {
>> - __builtin_memcpy(__res.get(), __sv.data(),
>> __sv.size());
>> + ranges::copy(__sv, __res.get());
>> __res._M_bump(__sv.size());
>> __done = true;
>> }
>> @@ -5347,14 +5405,16 @@ namespace __format
>> __scanner._M_scan();
>> return __out;
>> }
>> - else if constexpr (__contiguous_char_iter<_CharT, _Out>)
>> - {
>> - _Ptr_sink<_CharT> __sink(__out);
>> - __format::__do_vformat_to(__sink.out(), __fmt, __args, __loc);
>> - return std::move(__sink)._M_finish(__out).out;
>> - }
>> else
>> {
>> + if constexpr (__contiguous_char_iter<_CharT, _Out>)
>> + if (!std::is_constant_evaluated())
>> + {
>> + _Ptr_sink<_CharT> __sink(__out);
>> + __format::__do_vformat_to(__sink.out(), __fmt, __args,
>> __loc);
>> + return std::move(__sink)._M_finish(__out).out;
>> + }
>> +
>> _Iter_sink<_CharT, _Out> __sink(std::move(__out));
>> __format::__do_vformat_to(__sink.out(), __fmt, __args, __loc);
>> return std::move(__sink)._M_finish().out;
>> @@ -5362,7 +5422,7 @@ namespace __format
>> }
>>
>> template<typename _Out, typename _CharT>
>> - format_to_n_result<_Out>
>> + _GLIBCXX26_CONSTEXPR format_to_n_result<_Out>
>> __do_vformat_to_n(_Out __out, iter_difference_t<_Out> __n,
>> basic_string_view<_CharT> __fmt,
>> const type_identity_t<
>> @@ -5402,7 +5462,11 @@ namespace __format
>> if constexpr (sizeof...(_Ts) != 0)
>> {
>> using _Parse_ctx = __format::_Scanner<_CharT>::_Parse_context;
>> - auto __arg = static_cast<_Parse_ctx*>(this)->_M_types[__id];
>> + auto* __args = static_cast<_Parse_ctx*>(this)->_M_types;
>> + // formatting scanner
>> + if (!__args)
>> + return;
>> + auto __arg = __args[__id];
>> __format::_Arg_t __types[] = {
>> __format::__to_arg_t_enum<_CharT, _Ts>()...
>> };
>> @@ -5432,14 +5496,14 @@ namespace __format
>>
>> template<typename _Out> requires output_iterator<_Out, const char&>
>> [[__gnu__::__always_inline__]]
>> - inline _Out
>> + inline _GLIBCXX26_CONSTEXPR _Out
>> vformat_to(_Out __out, string_view __fmt, format_args __args)
>> { return __format::__do_vformat_to(std::move(__out), __fmt, __args);
>> }
>>
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> template<typename _Out> requires output_iterator<_Out, const wchar_t&>
>> [[__gnu__::__always_inline__]]
>> - inline _Out
>> + inline _GLIBCXX26_CONSTEXPR _Out
>> vformat_to(_Out __out, wstring_view __fmt, wformat_args __args)
>> { return __format::__do_vformat_to(std::move(__out), __fmt, __args);
>> }
>> #endif
>> @@ -5465,7 +5529,7 @@ namespace __format
>> #endif
>>
>> [[nodiscard]]
>> - inline string
>> + inline _GLIBCXX26_CONSTEXPR string
>> vformat(string_view __fmt, format_args __args)
>> {
>> __format::_Str_sink<char> __buf;
>> @@ -5475,7 +5539,7 @@ namespace __format
>>
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> [[nodiscard]]
>> - inline wstring
>> + inline _GLIBCXX26_CONSTEXPR wstring
>> vformat(wstring_view __fmt, wformat_args __args)
>> {
>> __format::_Str_sink<wchar_t> __buf;
>> @@ -5506,14 +5570,14 @@ namespace __format
>>
>> template<typename... _Args>
>> [[nodiscard]]
>> - inline string
>> + inline _GLIBCXX26_CONSTEXPR string
>> format(format_string<_Args...> __fmt, _Args&&... __args)
>> { return std::vformat(__fmt.get(),
>> std::make_format_args(__args...)); }
>>
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> template<typename... _Args>
>> [[nodiscard]]
>> - inline wstring
>> + inline _GLIBCXX26_CONSTEXPR wstring
>> format(wformat_string<_Args...> __fmt, _Args&&... __args)
>> { return std::vformat(__fmt.get(),
>> std::make_wformat_args(__args...)); }
>> #endif
>> @@ -5542,7 +5606,7 @@ namespace __format
>>
>> template<typename _Out, typename... _Args>
>> requires output_iterator<_Out, const char&>
>> - inline _Out
>> + inline _GLIBCXX26_CONSTEXPR _Out
>> format_to(_Out __out, format_string<_Args...> __fmt, _Args&&...
>> __args)
>> {
>> return std::vformat_to(std::move(__out), __fmt.get(),
>> @@ -5552,7 +5616,7 @@ namespace __format
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> template<typename _Out, typename... _Args>
>> requires output_iterator<_Out, const wchar_t&>
>> - inline _Out
>> + inline _GLIBCXX26_CONSTEXPR _Out
>> format_to(_Out __out, wformat_string<_Args...> __fmt, _Args&&...
>> __args)
>> {
>> return std::vformat_to(std::move(__out), __fmt.get(),
>> @@ -5584,7 +5648,7 @@ namespace __format
>>
>> template<typename _Out, typename... _Args>
>> requires output_iterator<_Out, const char&>
>> - inline format_to_n_result<_Out>
>> + inline _GLIBCXX26_CONSTEXPR format_to_n_result<_Out>
>> format_to_n(_Out __out, iter_difference_t<_Out> __n,
>> format_string<_Args...> __fmt, _Args&&... __args)
>> {
>> @@ -5596,7 +5660,7 @@ namespace __format
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> template<typename _Out, typename... _Args>
>> requires output_iterator<_Out, const wchar_t&>
>> - inline format_to_n_result<_Out>
>> + inline _GLIBCXX26_CONSTEXPR format_to_n_result<_Out>
>> format_to_n(_Out __out, iter_difference_t<_Out> __n,
>> wformat_string<_Args...> __fmt, _Args&&... __args)
>> {
>> @@ -5638,10 +5702,11 @@ namespace __format
>> class _Counting_sink final : public _Ptr_sink<_CharT>
>> {
>> public:
>> + _GLIBCXX26_CONSTEXPR
>> _Counting_sink() : _Ptr_sink<_CharT>(nullptr, 0) { }
>>
>> [[__gnu__::__always_inline__]]
>> - size_t
>> + _GLIBCXX26_CONSTEXPR size_t
>> count() const
>> { return this->_M_count + this->_M_used().size(); }
>> };
>> @@ -5676,7 +5741,7 @@ namespace __format
>>
>> template<typename... _Args>
>> [[nodiscard]]
>> - inline size_t
>> + inline _GLIBCXX26_CONSTEXPR size_t
>> formatted_size(format_string<_Args...> __fmt, _Args&&... __args)
>> {
>> __format::_Counting_sink<char> __buf;
>> @@ -5688,7 +5753,7 @@ namespace __format
>> #ifdef _GLIBCXX_USE_WCHAR_T
>> template<typename... _Args>
>> [[nodiscard]]
>> - inline size_t
>> + inline _GLIBCXX26_CONSTEXPR size_t
>> formatted_size(wformat_string<_Args...> __fmt, _Args&&... __args)
>> {
>> __format::_Counting_sink<wchar_t> __buf;
>> @@ -5759,6 +5824,7 @@ namespace __format
>> namespace __format
>> {
>> template<typename _CharT, typename _Out, typename _Callback>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> __format_padded(basic_format_context<_Out, _CharT>& __fc,
>> const _Spec<_CharT>& __spec,
>> @@ -5778,14 +5844,16 @@ namespace __format
>>
>> struct _Restore_out
>> {
>> + _GLIBCXX26_CONSTEXPR
>> _Restore_out(basic_format_context<_Sink_iter<_CharT>, _CharT>&
>> __fc)
>> : _M_ctx(std::addressof(__fc)), _M_out(__fc.out())
>> { }
>>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_disarm()
>> { _M_ctx = nullptr; }
>>
>> + _GLIBCXX26_CONSTEXPR
>> ~_Restore_out()
>> {
>> if (_M_ctx)
>> @@ -5819,7 +5887,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_format(__maybe_const<_Tp, _CharT>& __elem,
>> basic_format_context<_Out, _CharT>& __fc,
>> basic_string_view<_CharT> __sep) const
>> @@ -5917,12 +5985,14 @@ namespace __format
>>
>> protected:
>> template<typename _Tuple, typename _Out, size_t... _Ids>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> _M_format(_Tuple& __tuple, index_sequence<_Ids...>,
>> basic_format_context<_Out, _CharT>& __fc) const
>> { return _M_format_elems(std::get<_Ids>(__tuple)..., __fc); }
>>
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> _M_format_elems(__maybe_const<_Tps, _CharT>&... __elems,
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -5952,7 +6022,7 @@ namespace __format
>> }
>>
>> template<typename _Out>
>> - void
>> + _GLIBCXX26_CONSTEXPR void
>> _M_format(__maybe_const<_Tps, _CharT>&... __elems,
>> basic_format_context<_Out, _CharT>& __fc,
>> _String_view __sep) const
>> @@ -5968,7 +6038,7 @@ namespace __format
>> };
>>
>> template<size_t... _Ids>
>> - static auto
>> + static _GLIBCXX26_CONSTEXPR auto
>> _S_create_storage(index_sequence<_Ids...>)
>> -> __formatters_storage<_Ids...>;
>> using _Formatters
>> @@ -6004,6 +6074,7 @@ namespace __format
>> // We deviate from standard, that declares this as template
>> accepting
>> // unconstrained FormatContext type, which seems unimplementable.
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(__maybe_const_pair& __p,
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -6031,6 +6102,7 @@ namespace __format
>> // We deviate from standard, that declares this as template
>> accepting
>> // unconstrained FormatContext type, which seems unimplementable.
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(__maybe_const_tuple& __t,
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -6194,6 +6266,7 @@ namespace __format
>> template<ranges::input_range _Rg, typename _Out>
>> requires formattable<ranges::range_reference_t<_Rg>, _CharT> &&
>> same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>,
>> _Tp>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(_Rg&& __rg, basic_format_context<_Out, _CharT>& __fc) const
>> {
>> @@ -6206,6 +6279,7 @@ namespace __format
>>
>> private:
>> template<ranges::input_range _Rg, typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> _M_format(_Rg& __rg, basic_format_context<_Out, _CharT>& __fc)
>> const
>> {
>> @@ -6223,6 +6297,7 @@ namespace __format
>>
>>
>> template<ranges::input_range _Rg, typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> _M_format_elems(_Rg& __rg,
>> basic_format_context<_Out, _CharT>& __fc) const
>> @@ -6322,6 +6397,7 @@ namespace __format
>> // We deviate from standard, that declares this as template
>> accepting
>> // unconstrained FormatContext type, which seems unimplementable.
>> template<typename _Out>
>> + _GLIBCXX26_CONSTEXPR
>> typename basic_format_context<_Out, _CharT>::iterator
>> format(__format::__maybe_const_range<_Rg, _CharT>& __rg,
>> basic_format_context<_Out, _CharT>& __fc) const
>> diff --git a/libstdc++-v3/testsuite/std/format/constexpr.cc
>> b/libstdc++-v3/testsuite/std/format/constexpr.cc
>> new file mode 100644
>> index 00000000000..675641cdbcb
>> --- /dev/null
>> +++ b/libstdc++-v3/testsuite/std/format/constexpr.cc
>> @@ -0,0 +1,126 @@
>> +// { dg-do compile { target c++26 } }
>> +
>> +#include <format>
>> +#include <string>
>> +#include <string_view>
>> +#include <tuple>
>> +#include <vector>
>> +#include <testsuite_hooks.h>
>> +
>> +constexpr void
>> +test_format()
>> +{
>> + using namespace std;
>> + string res;
>> +
>> + res = format("{}", 'c');
>> + VERIFY( res == "c" );
>> + res = format("{1} {0} {0}", 'a', 'b');
>> + VERIFY( res == "b a a" );
>> + res = format("{:?}", '\n');
>> + VERIFY( res == "'\\n'" );
>> + res = format("{:.^10}", "hello");
>> + VERIFY( res == "..hello..." );
>> + res = format("{:.>{}}", "world", 8);
>> + VERIFY( res == "...world" );
>> + res = format("{:+#06X}", 0xa);
>> + VERIFY( res == "+0X00A" );
>> + res = format("{:p}", nullptr);
>> + VERIFY( res == "0x0" );
>> + res = format("{:07P}", nullptr);
>> + VERIFY( res == "0X00000" );
>> + res = format("{} {}", true, false);
>> + VERIFY( res == "true false" );
>> + res = format("{:+#06b}", true);
>> + VERIFY( res == "+0b001" );
>> + res = format("{} {} {} {}", "abc", +"def", string_view("ghi"),
>> string("jkl"));
>> + VERIFY( res == "abc def ghi jkl" );
>> + res = format("{:?}", "hello\nworld");
>> + VERIFY( res == "\"hello\\nworld\"" );
>> + res = format("{}", tuple(1, true));
>> + VERIFY( res == "(1, true)" );
>> + res = format("{:t<12m}", tuple('a', "bc"));
>> + VERIFY( res == "'a': \"bc\"ttt" );
>> + res = format("{:n}", tuple(nullptr, -1, 1));
>> + VERIFY( res == "0x0, -1, 1" );
>> + res = format("{}", vector{1, 2, 3, 4});
>> + VERIFY( res == "[1, 2, 3, 4]" );
>> + res = format("{:?s}", vector{'a', '\n', 'b'});
>> + VERIFY( res == "\"a\\nb\"" );
>> + res = format("{:n:+}", vector{1, 2, 3});
>> + VERIFY( res == "+1, +2, +3" );
>> +}
>> +
>> +constexpr void
>> +test_format_to()
>> +{
>> + using namespace std;
>> + char buf[100];
>> + char* out;
>> +
>> + out = format_to(buf, "{:.^5}", "foo");
>> + VERIFY( string_view(buf, out) == ".foo." );
>> + out = format_to(buf, "{} {}", nullptr, true);
>> + VERIFY( string_view(buf, out) == "0x0 true" );
>> +}
>> +
>> +constexpr void
>> +test_vformat()
>> +{
>> + using namespace std;
>> + string res;
>> +
>> + int arg1 = 1;
>> + char arg2 = 'a';
>> + bool arg3 = true;
>> + res = vformat("{} {:?} {}", make_format_args(arg1, arg2, arg3));
>> + VERIFY( res == "1 'a' true" );
>> +}
>> +
>> +constexpr void
>> +test_vformat_to()
>> +{
>> + using namespace std;
>> + char buf[100];
>> + char* out;
>> +
>> + nullptr_t arg1 = nullptr;
>> + string arg2 = "foo";
>> + tuple<int, int> arg3{-3, 5};
>> + out = vformat_to(buf, "{} {:?} {}", make_format_args(arg1, arg2,
>> arg3));
>> + VERIFY( string_view(buf, out) == "0x0 \"foo\" (-3, 5)" );
>> +}
>> +
>> +constexpr void
>> +test_format_to_n()
>> +{
>> + using namespace std;
>> + char buf[100];
>> + format_to_n_result<char*> out;
>> + int n;
>> +
>> + n = 100;
>> + out = format_to_n(buf, n, "{:+} {:?} {}", 1, "\n\n", vector{1, 2, 3});
>> + VERIFY( out.size <= n );
>> + VERIFY( out.out - buf == out.size );
>> + VERIFY( string_view(buf, out.size) == "+1 \"\\n\\n\" [1, 2, 3]" );
>> + n = 12;
>> + out = format_to_n(buf, n, "{} {} {}", true, nullptr, "long string");
>> + VERIFY( out.size > n );
>> + VERIFY( out.out - buf == n );
>> + VERIFY( string_view(buf, out.out) == "true 0x0 lon" );
>> +}
>> +
>> +constexpr bool
>> +all_tests()
>> +{
>> + test_format();
>> + test_format_to();
>> + test_vformat();
>> + test_vformat_to();
>> + test_format_to_n();
>> +
>> + return true;
>> +}
>> +
>> +static_assert(all_tests());
>> diff --git a/libstdc++-v3/testsuite/std/format/debug.cc
>> b/libstdc++-v3/testsuite/std/format/debug.cc
>> index 43e930c579e..c45659d0d69 100644
>> --- a/libstdc++-v3/testsuite/std/format/debug.cc
>> +++ b/libstdc++-v3/testsuite/std/format/debug.cc
>> @@ -1,14 +1,20 @@
>> -// { dg-options "-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32LE
>> -DUNICODE_ENC" { target le } }
>> -// { dg-options "-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32BE
>> -DUNICODE_ENC" { target be } }
>> +// { dg-options "-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32LE
>> -DUNICODE_ENC -fconstexpr-ops-limit=500000000" { target le } }
>> +// { dg-options "-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32BE
>> -DUNICODE_ENC -fconstexpr-ops-limit=500000000" { target be } }
>> // { dg-do run { target c++23 } }
>> // { dg-require-effective-target 4byte_wchar_t }
>> // { dg-add-options no_pch }
>> // { dg-timeout-factor 2 }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <format>
>> #include <testsuite_hooks.h>
>>
>> -std::string
>> +constexpr26 std::string
>> fdebug(char t)
>> { return std::format("{:?}", t); }
>>
>> @@ -16,7 +22,7 @@ std::wstring
>> fdebug(wchar_t t)
>> { return std::format(L"{:?}", t); }
>>
>> -std::string
>> +constexpr26 std::string
>> fdebug(std::string_view t)
>> { return std::format("{:?}", t); }
>>
>> @@ -29,7 +35,7 @@ fdebug(std::wstring_view t)
>> #define WIDEN(S) WIDEN_(CharT, S)
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_basic_escapes()
>> {
>> std::basic_string<CharT> res;
>> @@ -72,7 +78,7 @@ test_basic_escapes()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_ascii_escapes()
>> {
>> std::basic_string<CharT> res;
>> @@ -89,7 +95,7 @@ test_ascii_escapes()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_extended_ascii()
>> {
>> std::basic_string<CharT> res;
>> @@ -117,7 +123,7 @@ test_extended_ascii()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_unicode_escapes()
>> {
>> #if UNICODE_ENC
>> @@ -166,7 +172,7 @@ test_unicode_escapes()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_grapheme_extend()
>> {
>> #if UNICODE_ENC
>> @@ -192,7 +198,7 @@ test_grapheme_extend()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_replacement_char()
>> {
>> #if UNICODE_ENC
>> @@ -206,7 +212,7 @@ test_replacement_char()
>> #endif // UNICODE_ENC
>> }
>>
>> -void
>> +constexpr26 void
>> test_ill_formed_utf8_seq()
>> {
>> #if UNICODE_ENC
>> @@ -269,7 +275,7 @@ test_ill_formed_utf32()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_fill()
>> {
>> std::basic_string<CharT> res;
>> @@ -315,7 +321,7 @@ test_fill()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_prec()
>> {
>> std::basic_string<CharT> res;
>> @@ -341,7 +347,8 @@ test_prec()
>> #endif // UNICODE_ENC
>> }
>>
>> -bool strip_quote(std::string_view& v)
>> +constexpr26 bool
>> +strip_quote(std::string_view& v)
>> {
>> if (!v.starts_with('"'))
>> return false;
>> @@ -349,7 +356,8 @@ bool strip_quote(std::string_view& v)
>> return true;
>> }
>>
>> -bool strip_quotes(std::string_view& v)
>> +constexpr26 bool
>> +strip_quotes(std::string_view& v)
>> {
>> if (!v.starts_with('"') || !v.ends_with('"'))
>> return false;
>> @@ -358,7 +366,8 @@ bool strip_quotes(std::string_view& v)
>> return true;
>> }
>>
>> -bool strip_prefix(std::string_view& v, size_t n, char c)
>> +constexpr26 bool
>> +strip_prefix(std::string_view& v, size_t n, char c)
>> {
>> size_t pos = v.find_first_not_of(c);
>> if (pos == std::string_view::npos)
>> @@ -369,7 +378,8 @@ bool strip_prefix(std::string_view& v, size_t n, char
>> c)
>> return true;
>> }
>>
>> -void test_padding()
>> +constexpr26 void
>> +test_padding()
>> {
>> std::string res;
>> std::string_view resv;
>> @@ -751,8 +761,9 @@ struct std::formatter<DebugWrapper<T>, CharT>
>> }
>>
>> template<typename Out>
>> - Out format(DebugWrapper<T> const& t,
>> - std::basic_format_context<Out, CharT>& fc) const
>> + constexpr26 Out
>> + format(DebugWrapper<T> const& t,
>> + std::basic_format_context<Out, CharT>& fc) const
>> { return under.format(t.val, fc); }
>>
>> private:
>> @@ -760,7 +771,7 @@ private:
>> };
>>
>> template<typename CharT, typename StrT>
>> -void
>> +constexpr26 void
>> test_formatter_str()
>> {
>> CharT buf[]{ 'a', 'b', 'c', 0 };
>> @@ -770,7 +781,7 @@ test_formatter_str()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_formatter_arr()
>> {
>> std::basic_string<CharT> res;
>> @@ -786,7 +797,7 @@ test_formatter_arr()
>> }
>>
>> template<typename CharT, typename SrcT>
>> -void
>> +constexpr26 void
>> test_formatter_char()
>> {
>> DebugWrapper<SrcT> in{ 'a' };
>> @@ -795,7 +806,7 @@ test_formatter_char()
>> }
>>
>> template<typename CharT>
>> -void
>> +constexpr26 void
>> test_formatters()
>> {
>> test_formatter_char<CharT, CharT>();
>> @@ -806,38 +817,60 @@ test_formatters()
>> test_formatter_arr<CharT>();
>> }
>>
>> -void
>> +constexpr26 void
>> test_formatters_c()
>> {
>> test_formatters<char>();
>> - test_formatters<wchar_t>();
>> - test_formatter_char<wchar_t, char>();
>> + if (!std::is_constant_evaluated())
>> + {
>> + test_formatters<wchar_t>();
>> + test_formatter_char<wchar_t, char>();
>> + }
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> test_basic_escapes<char>();
>> - test_basic_escapes<wchar_t>();
>> test_ascii_escapes<char>();
>> - test_ascii_escapes<wchar_t>();
>> test_extended_ascii<char>();
>> - test_extended_ascii<wchar_t>();
>>
>> test_unicode_escapes<char>();
>> - test_unicode_escapes<wchar_t>();
>> test_grapheme_extend<char>();
>> - test_grapheme_extend<wchar_t>();
>> test_replacement_char<char>();
>> - test_replacement_char<wchar_t>();
>> test_ill_formed_utf8_seq();
>> - test_ill_formed_utf32();
>>
>> test_fill<char>();
>> - test_fill<wchar_t>();
>> test_prec<char>();
>> - test_prec<wchar_t>();
>> +
>> + // constexpr wide formatting not yet implemented
>> + if (!std::is_constant_evaluated())
>> + {
>> + test_basic_escapes<wchar_t>();
>> + test_ascii_escapes<wchar_t>();
>> + test_extended_ascii<wchar_t>();
>> +
>> + test_unicode_escapes<wchar_t>();
>> + test_grapheme_extend<wchar_t>();
>> + test_replacement_char<wchar_t>();
>> + test_ill_formed_utf32();
>> +
>> + test_fill<wchar_t>();
>> + test_prec<wchar_t>();
>> + }
>>
>> test_padding();
>>
>> test_formatters_c();
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/functions/format.cc
>> b/libstdc++-v3/testsuite/std/format/functions/format.cc
>> index d342114083e..9d921d59d5f 100644
>> --- a/libstdc++-v3/testsuite/std/format/functions/format.cc
>> +++ b/libstdc++-v3/testsuite/std/format/functions/format.cc
>> @@ -3,6 +3,12 @@
>> // { dg-add-options no_pch }
>> // { dg-additional-options "-DUNICODE" { target 4byte_wchar_t } }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <format>
>>
>> #ifndef __cpp_lib_format
>> @@ -41,7 +47,7 @@
>> #include <cstdio>
>> #include <testsuite_hooks.h>
>>
>> -void
>> +constexpr26 void
>> test_no_args()
>> {
>> std::string s;
>> @@ -55,6 +61,7 @@ test_no_args()
>> VERIFY( s == "128bpm }" );
>> }
>>
>> +// not constexpr because of PR124145
>> void
>> test_unescaped()
>> {
>> @@ -78,7 +85,7 @@ struct brit_punc : std::numpunct<char>
>> std::string do_falsename() const override { return "nah bruv"; }
>> };
>>
>> -void
>> +constexpr26 void
>> test_std_examples()
>> {
>> using namespace std;
>> @@ -125,10 +132,13 @@ test_std_examples()
>> VERIFY(s0 == "1,+1,1, 1");
>> string s1 = format("{0:},{0:+},{0:-},{0: }", -1);
>> VERIFY(s1 == "-1,-1,-1,-1");
>> - string s2 = format("{0:},{0:+},{0:-},{0: }", inf);
>> - VERIFY(s2 == "inf,+inf,inf, inf");
>> - string s3 = format("{0:},{0:+},{0:-},{0: }", nan);
>> - VERIFY(s3 == "nan,+nan,nan, nan");
>> + if (!std::is_constant_evaluated())
>> + {
>> + string s2 = format("{0:},{0:+},{0:-},{0: }", inf);
>> + VERIFY(s2 == "inf,+inf,inf, inf");
>> + string s3 = format("{0:},{0:+},{0:-},{0: }", nan);
>> + VERIFY(s3 == "nan,+nan,nan, nan");
>> + }
>> }
>>
>> // alternate form and zero fill
>> @@ -143,34 +153,35 @@ test_std_examples()
>> }
>>
>> // integer presentation types
>> - {
>> - // Change global locale so "{:L}" adds digit separators.
>> - std::locale::global(std::locale({}, new brit_punc));
>> -
>> - string s0 = format("{}", 42);
>> - VERIFY(s0 == "42");
>> - string s1 = format("{0:b} {0:d} {0:o} {0:x}", 42);
>> - VERIFY(s1 == "101010 42 52 2a");
>> - string s2 = format("{0:#x} {0:#X}", 42);
>> - VERIFY(s2 == "0x2a 0X2A");
>> - string s3 = format("{:L}", 1234);
>> - VERIFY(s3 == "1,234");
>> -
>> - // Test locale's "byte-and-a-half" grouping (Imperial word?
>> tribble?).
>> - string s4 = format("{:#Lx}", 0xfffff);
>> - VERIFY(s4 == "0xff,fff");
>> -
>> - // Restore
>> - std::locale::global(std::locale::classic());
>> -
>> - string s5 = format("{}", -100); // PR libstdc++/114325
>> - VERIFY(s5 == "-100");
>> - string s6 = format("{:d} {:d}", -123, 999);
>> - VERIFY(s6 == "-123 999");
>> - }
>> + if (!std::is_constant_evaluated())
>> + {
>> + // Change global locale so "{:L}" adds digit separators.
>> + std::locale::global(std::locale({}, new brit_punc));
>> +
>> + string s0 = format("{}", 42);
>> + VERIFY(s0 == "42");
>> + string s1 = format("{0:b} {0:d} {0:o} {0:x}", 42);
>> + VERIFY(s1 == "101010 42 52 2a");
>> + string s2 = format("{0:#x} {0:#X}", 42);
>> + VERIFY(s2 == "0x2a 0X2A");
>> + string s3 = format("{:L}", 1234);
>> + VERIFY(s3 == "1,234");
>> +
>> + // Test locale's "byte-and-a-half" grouping (Imperial word?
>> tribble?).
>> + string s4 = format("{:#Lx}", 0xfffff);
>> + VERIFY(s4 == "0xff,fff");
>> +
>> + // Restore
>> + std::locale::global(std::locale::classic());
>> +
>> + string s5 = format("{}", -100); // PR libstdc++/114325
>> + VERIFY(s5 == "-100");
>> + string s6 = format("{:d} {:d}", -123, 999);
>> + VERIFY(s6 == "-123 999");
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_alternate_forms()
>> {
>> std::string s;
>> @@ -180,23 +191,26 @@ test_alternate_forms()
>> s = std::format("{0:#b} {0:+#B} {0:#o} {0:#x} {0:+#X} {0: #d}", 0);
>> VERIFY( s == "0b0 +0B0 0 0x0 +0X0 0" );
>>
>> - s = std::format("{0:+#012g} {0:+#014g} {0:+#014g}", 1234.0);
>> - VERIFY( s == "+00001234.00 +0000001234.00 +0000001234.00" );
>> - s = std::format("{0:+#0{1}g} {0:+#0{2}g} {0:+#0{2}g}", 1234.5, 12, 14);
>> - VERIFY( s == "+00001234.50 +0000001234.50 +0000001234.50" );
>> -
>> - s = std::format("{:#.2g}", -0.0);
>> - VERIFY( s == "-0.0" );
>> -
>> - // PR libstdc++/108046
>> - s = std::format("{0:#.0} {0:#.1} {0:#.0g}", 10.0);
>> - VERIFY( s == "1.e+01 1.e+01 1.e+01" );
>> -
>> - // PR libstdc++/113512
>> - s = std::format("{:#.3g}", 0.025);
>> - VERIFY( s == "0.0250" );
>> - s = std::format("{:#07.3g}", 0.02);
>> - VERIFY( s == "00.0200" );
>> + if (!std::is_constant_evaluated())
>> + {
>> + s = std::format("{0:+#012g} {0:+#014g} {0:+#014g}", 1234.0);
>> + VERIFY( s == "+00001234.00 +0000001234.00 +0000001234.00" );
>> + s = std::format("{0:+#0{1}g} {0:+#0{2}g} {0:+#0{2}g}", 1234.5, 12,
>> 14);
>> + VERIFY( s == "+00001234.50 +0000001234.50 +0000001234.50" );
>> +
>> + s = std::format("{:#.2g}", -0.0);
>> + VERIFY( s == "-0.0" );
>> +
>> + // PR libstdc++/108046
>> + s = std::format("{0:#.0} {0:#.1} {0:#.0g}", 10.0);
>> + VERIFY( s == "1.e+01 1.e+01 1.e+01" );
>> +
>> + // PR libstdc++/113512
>> + s = std::format("{:#.3g}", 0.025);
>> + VERIFY( s == "0.0250" );
>> + s = std::format("{:#07.3g}", 0.02);
>> + VERIFY( s == "00.0200" );
>> + }
>> }
>>
>> void
>> @@ -275,7 +289,7 @@ test_locale()
>> std::locale::global(cloc);
>> }
>>
>> -void
>> +constexpr26 void
>> test_width()
>> {
>> std::string s;
>> @@ -294,30 +308,34 @@ test_width()
>> s = std::format("DR {0:{1}}: allow width {1} from arg-id", 3721, 0);
>> VERIFY( s == "DR 3721: allow width 0 from arg-id" );
>>
>> - try {
>> - s = std::format("Negative width is an error: {0:{1}}", 123, -1);
>> - VERIFY(false);
>> - } catch (const std::format_error&) {
>> - }
>> -
>> - try {
>> - bool no = false, yes = true;
>> - auto args = std::make_format_args(no, yes);
>> - s = std::vformat("DR 3720: restrict type of width arg-id {0:{1}}",
>> args);
>> - VERIFY(false);
>> - } catch (const std::format_error&) {
>> - }
>> -
>> - try {
>> - char wat = '?', bang = '!';
>> - auto args = std::make_format_args(wat, bang);
>> - s = std::vformat("DR 3720: restrict type of width arg-id {0:{1}}",
>> args);
>> - VERIFY(false);
>> - } catch (const std::format_error&) {
>> - }
>> + // not constexpr because of PR124145
>> + if (!std::is_constant_evaluated())
>> + {
>> + try {
>> + s = std::format("Negative width is an error: {0:{1}}", 123, -1);
>> + VERIFY(false);
>> + } catch (const std::format_error&) {
>> + }
>> +
>> + try {
>> + bool no = false, yes = true;
>> + auto args = std::make_format_args(no, yes);
>> + s = std::vformat("DR 3720: restrict type of width arg-id
>> {0:{1}}", args);
>> + VERIFY(false);
>> + } catch (const std::format_error&) {
>> + }
>> +
>> + try {
>> + char wat = '?', bang = '!';
>> + auto args = std::make_format_args(wat, bang);
>> + s = std::vformat("DR 3720: restrict type of width arg-id
>> {0:{1}}", args);
>> + VERIFY(false);
>> + } catch (const std::format_error&) {
>> + }
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_char()
>> {
>> std::string s;
>> @@ -347,6 +365,7 @@ test_char()
>> VERIFY( s == "11110000 11110000 240 360 f0 F0" );
>> }
>>
>> +// constexpr wide formatting not yet implemented
>> void
>> test_wchar()
>> {
>> @@ -395,7 +414,7 @@ test_wchar()
>> VERIFY( ws == L"0.5" );
>> }
>>
>> -void
>> +constexpr26 void
>> test_minmax()
>> {
>> auto check = []<typename T, typename U = std::make_unsigned_t<T>>(T, U
>> = 0) {
>> @@ -422,7 +441,7 @@ test_minmax()
>> #endif
>> }
>>
>> -void
>> +constexpr26 void
>> test_p1652r1() // printf corner cases in std::format
>> {
>> std::string s;
>> @@ -436,27 +455,33 @@ test_p1652r1() // printf corner cases in std::format
>> s = std::format("{:c}", c);
>> VERIFY( s == "A" );
>>
>> - // Problem 3: "-000nan" is not a floating point value
>> - double nan = std::numeric_limits<double>::quiet_NaN();
>> - try {
>> - s = std::vformat("{:0=6}", std::make_format_args(nan));
>> - VERIFY( false );
>> - } catch (const std::format_error&) {
>> - }
>> -
>> - s = std::format("{:06}", nan);
>> - VERIFY( s == " nan" );
>> + if (!std::is_constant_evaluated())
>> + {
>> + // Problem 3: "-000nan" is not a floating point value
>> + double nan = std::numeric_limits<double>::quiet_NaN();
>> + try {
>> + s = std::vformat("{:0=6}", std::make_format_args(nan));
>> + VERIFY( false );
>> + } catch (const std::format_error&) {
>> + }
>> +
>> + s = std::format("{:06}", nan);
>> + VERIFY( s == " nan" );
>> + }
>>
>> // Problem 4: bool needs a type format specifier
>> s = std::format("{:s}", true);
>> VERIFY( s == "true" );
>>
>> - // Problem 5: double does not roundtrip float
>> - s = std::format("{}", 3.31f);
>> - VERIFY( s == "3.31" );
>> + if (!std::is_constant_evaluated())
>> + {
>> + // Problem 5: double does not roundtrip float
>> + s = std::format("{}", 3.31f);
>> + VERIFY( s == "3.31" );
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_pointer()
>> {
>> void* p = nullptr;
>> @@ -477,28 +502,31 @@ test_pointer()
>> s = std::format("{:o<4},{:o>5},{:o^7}", p, pc, nullptr); //
>> fill+align+width
>> VERIFY( s == "0x0o,oo0x0,oo0x0oo" );
>>
>> - pc = p = &s;
>> - str_int = std::format("{:#x}", reinterpret_cast<std::uintptr_t>(p));
>> - s = std::format("{} {} {}", p, pc, nullptr);
>> - VERIFY( s == (str_int + ' ' + str_int + " 0x0") );
>> - str_int = std::format("{:#20x}", reinterpret_cast<std::uintptr_t>(p));
>> - s = std::format("{:20} {:20p}", p, pc);
>> - VERIFY( s == (str_int + ' ' + str_int) );
>> + if (!std::is_constant_evaluated())
>> + {
>> + pc = p = &s;
>> + str_int = std::format("{:#x}",
>> reinterpret_cast<std::uintptr_t>(p));
>> + s = std::format("{} {} {}", p, pc, nullptr);
>> + VERIFY( s == (str_int + ' ' + str_int + " 0x0") );
>> + str_int = std::format("{:#20x}",
>> reinterpret_cast<std::uintptr_t>(p));
>> + s = std::format("{:20} {:20p}", p, pc);
>> + VERIFY( s == (str_int + ' ' + str_int) );
>>
>> #if __cpp_lib_format >= 202304L
>> - // P2510R3 Formatting pointers
>> - s = std::format("{:06} {:07P} {:08p}", (void*)0, (const void*)0,
>> nullptr);
>> - VERIFY( s == "0x0000 0X00000 0x000000" );
>> - str_int = std::format("{:#016x}", reinterpret_cast<std::uintptr_t>(p));
>> - s = std::format("{:016} {:016}", p, pc);
>> - VERIFY( s == (str_int + ' ' + str_int) );
>> - str_int = std::format("{:#016X}", reinterpret_cast<std::uintptr_t>(p));
>> - s = std::format("{:016P} {:016P}", p, pc);
>> - VERIFY( s == (str_int + ' ' + str_int) );
>> + // P2510R3 Formatting pointers
>> + s = std::format("{:06} {:07P} {:08p}", (void*)0, (const void*)0,
>> nullptr);
>> + VERIFY( s == "0x0000 0X00000 0x000000" );
>> + str_int = std::format("{:#016x}",
>> reinterpret_cast<std::uintptr_t>(p));
>> + s = std::format("{:016} {:016}", p, pc);
>> + VERIFY( s == (str_int + ' ' + str_int) );
>> + str_int = std::format("{:#016X}",
>> reinterpret_cast<std::uintptr_t>(p));
>> + s = std::format("{:016P} {:016P}", p, pc);
>> + VERIFY( s == (str_int + ' ' + str_int) );
>> #endif
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_bool()
>> {
>> std::string s;
>> @@ -519,7 +547,7 @@ test_bool()
>> VERIFY( s == "0 0x1 0X0" );
>> }
>>
>> -void
>> +constexpr26 void
>> test_unicode()
>> {
>> #ifdef UNICODE
>> @@ -579,19 +607,36 @@ test_unicode()
>> #endif
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> test_no_args();
>> - test_unescaped();
>> test_std_examples();
>> test_alternate_forms();
>> - test_locale();
>> test_width();
>> test_char();
>> - test_wchar();
>> test_minmax();
>> test_p1652r1();
>> test_pointer();
>> test_bool();
>> test_unicode();
>> +
>> + if (!std::is_constant_evaluated())
>> + {
>> + test_unescaped();
>> + test_infnan();
>> + test_locale();
>> + test_wchar();
>> + }
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/functions/format_to.cc
>> b/libstdc++-v3/testsuite/std/format/functions/format_to.cc
>> index 94e6262bc66..ae6ffb3a562 100644
>> --- a/libstdc++-v3/testsuite/std/format/functions/format_to.cc
>> +++ b/libstdc++-v3/testsuite/std/format/functions/format_to.cc
>> @@ -1,5 +1,11 @@
>> // { dg-do run { target c++20 } }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <format>
>> #include <locale>
>> #include <vector>
>> @@ -11,17 +17,20 @@ struct punct : std::numpunct<char>
>> std::string do_grouping() const override { return "\2"; }
>> };
>>
>> -void
>> +constexpr26 void
>> test()
>> {
>> char buf[32] = { };
>> auto out = std::format_to(buf, "test");
>> VERIFY( out == buf+4 );
>>
>> - std::locale loc({}, new punct);
>> - auto out2 = std::format_to(buf, loc, "{:Ld}", 12345);
>> - VERIFY( out2 == buf+7 );
>> - VERIFY( std::string_view(buf, out2 - buf) == "1,23,45" );
>> + if (!std::is_constant_evaluated())
>> + {
>> + std::locale loc({}, new punct);
>> + auto out2 = std::format_to(buf, loc, "{:Ld}", 12345);
>> + VERIFY( out2 == buf+7 );
>> + VERIFY( std::string_view(buf, out2 - buf) == "1,23,45" );
>> + }
>> }
>>
>> struct wpunct : std::numpunct<wchar_t>
>> @@ -29,6 +38,7 @@ struct wpunct : std::numpunct<wchar_t>
>> std::string do_grouping() const override { return "\2"; }
>> };
>>
>> +// constexpr wide formatting not yet implemented
>> void
>> test_wchar()
>> {
>> @@ -50,20 +60,20 @@ struct move_only_iterator
>> using difference_type = iterator::difference_type;
>> using iterator_category = std::output_iterator_tag;
>>
>> - move_only_iterator(iterator b) : base_(b) { }
>> + constexpr move_only_iterator(iterator b) : base_(b) { }
>> move_only_iterator(move_only_iterator&&) = default;
>> move_only_iterator& operator=(move_only_iterator&&) = default;
>>
>> - move_only_iterator& operator++() { ++base_; return *this; }
>> - move_only_iterator operator++(int) { auto tmp = *this; ++base_; return
>> tmp; }
>> + constexpr move_only_iterator& operator++() { ++base_; return *this; }
>> + constexpr move_only_iterator operator++(int) { auto tmp = *this;
>> ++base_; return tmp; }
>>
>> - decltype(auto) operator*() { return *base_; }
>> + constexpr decltype(auto) operator*() { return *base_; }
>>
>> private:
>> iterator base_;
>> };
>>
>> -void
>> +constexpr26 void
>> test_move_only()
>> {
>> std::string str;
>> @@ -72,14 +82,17 @@ test_move_only()
>> = std::format_to(std::move(mo), "for{:.3} that{:c}", "matte",
>> (int)'!');
>> VERIFY( str == "format that!" );
>>
>> - std::vector<wchar_t> vec;
>> - move_only_iterator wmo(std::back_inserter(vec));
>> - [[maybe_unused]] auto wres
>> - = std::format_to(std::move(wmo), L"for{:.3} hat{:c}", L"matte",
>> (long)L'!');
>> - VERIFY( std::wstring_view(vec.data(), vec.size()) == L"format hat!" );
>> + if (!std::is_constant_evaluated())
>> + {
>> + std::vector<wchar_t> vec;
>> + move_only_iterator wmo(std::back_inserter(vec));
>> + [[maybe_unused]] auto wres
>> + = std::format_to(std::move(wmo), L"for{:.3}
>> hat{:c}", L"matte", (long)L'!');
>> + VERIFY( std::wstring_view(vec.data(), vec.size()) == L"format
>> hat!" );
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_pr110917()
>> {
>> // PR libstdc++/110917
>> @@ -90,10 +103,24 @@ test_pr110917()
>> VERIFY( ! std::memcmp(buf, "abc 123", 7) );
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> test();
>> - test_wchar();
>> test_move_only();
>> test_pr110917();
>> +
>> + if (!std::is_constant_evaluated())
>> + test_wchar();
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/functions/size.cc
>> b/libstdc++-v3/testsuite/std/format/functions/size.cc
>> index 1ece4108d85..24220f632fe 100644
>> --- a/libstdc++-v3/testsuite/std/format/functions/size.cc
>> +++ b/libstdc++-v3/testsuite/std/format/functions/size.cc
>> @@ -1,10 +1,16 @@
>> // { dg-do run { target c++20 } }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <format>
>> #include <string>
>> #include <testsuite_hooks.h>
>>
>> -void
>> +constexpr26 void
>> test()
>> {
>> auto n = std::formatted_size("");
>> @@ -44,8 +50,20 @@ test_wchar()
>> VERIFY( n == 5 );
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> test();
>> - test_wchar();
>> + if (!std::is_constant_evaluated())
>> + test_wchar();
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/ranges/format_kind.cc
>> b/libstdc++-v3/testsuite/std/format/ranges/format_kind.cc
>> index 1450fbaebc5..48795440d13 100644
>> --- a/libstdc++-v3/testsuite/std/format/ranges/format_kind.cc
>> +++ b/libstdc++-v3/testsuite/std/format/ranges/format_kind.cc
>> @@ -1,5 +1,11 @@
>> // { dg-do run { target c++23 } }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <deque>
>> #include <flat_map>
>> #include <flat_set>
>> @@ -64,7 +70,8 @@ struct CustFormat : std::vector<T>
>> template<typename T, std::range_format rf>
>> constexpr auto std::format_kind<CustFormat<T, rf>> = rf;
>>
>> -void test_override()
>> +constexpr26 bool
>> +test_override()
>> {
>> CustFormat<int, std::range_format::disabled> disabledf;
>> static_assert( !std::formattable<decltype(disabledf), char> );
>> @@ -88,8 +95,14 @@ void test_override()
>> VERIFY( std::format("{}", debugf) == R"("abcd")" );
>> // Support precision as string do
>> VERIFY( std::format("{:.3}", debugf) == R"("ab)" );
>> +
>> + return true;
>> }
>>
>> +#if __cplusplus >= 202400L
>> +static_assert(test_override());
>> +#endif
>> +
>> int main()
>> {
>> test_override();
>> diff --git a/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
>> b/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
>> index a50c5b1033f..3bd5f37403e 100644
>> --- a/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
>> +++ b/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
>> @@ -1,5 +1,11 @@
>> // { dg-do run { target c++23 } }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <flat_map>
>> #include <format>
>> #include <testsuite_hooks.h>
>> @@ -32,7 +38,7 @@ struct std::formatter<MyVector<T, Formatter>, CharT>
>> { return _formatter.parse(pc); }
>>
>> template<typename Out>
>> - typename std::basic_format_context<Out, CharT>::iterator
>> + constexpr26 std::basic_format_context<Out, CharT>::iterator
>> format(const MyVector<T, Formatter>& mv,
>> std::basic_format_context<Out, CharT>& fc) const
>> { return _formatter.format(mv, fc); }
>> @@ -42,7 +48,7 @@ private:
>> };
>>
>> template<typename CharT, template<typename, typename> class Formatter>
>> -void
>> +constexpr26 void
>> test_default()
>> {
>> MyVector<int, Formatter> vec{1, 2, 3};
>> @@ -94,7 +100,7 @@ test_default()
>> }
>>
>> template<typename CharT, template<typename, typename> class Formatter>
>> -void
>> +constexpr26 void
>> test_override()
>> {
>> MyVector<CharT, Formatter> vc{'a', 'b', 'c', 'd'};
>> @@ -115,15 +121,20 @@ test_override()
>> }
>>
>> template<template<typename, typename> class Formatter>
>> -void test_outputs()
>> +constexpr26 void
>> +test_outputs()
>> {
>> test_default<char, Formatter>();
>> - test_default<wchar_t, Formatter>();
>> test_override<char, Formatter>();
>> - test_override<wchar_t, Formatter>();
>> + // constexpr wide formatting not yet implemented
>> + if (!std::is_constant_evaluated())
>> + {
>> + test_default<wchar_t, Formatter>();
>> + test_override<wchar_t, Formatter>();
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_nested()
>> {
>> MyVector<MyVector<int>> v
>> @@ -152,7 +163,8 @@ struct std::formatter<MyFlatMap, CharT>
>> : std::range_formatter<MyFlatMap::reference>
>> {};
>>
>> -void test_const_ref_type_mismatch()
>> +constexpr26 void
>> +test_const_ref_type_mismatch()
>> {
>> MyFlatMap m{{1, 11}, {2, 22}};
>> std::string res = std::format("{:m}", m);
>> @@ -163,13 +175,15 @@ template<typename T, typename CharT>
>> using VectorFormatter = std::formatter<std::vector<T>, CharT>;
>>
>> template<template<typename> typename Range>
>> -void test_nonblocking()
>> +constexpr26 void
>> +test_nonblocking()
>> {
>> static_assert(!std::enable_nonlocking_formatter_optimization<
>> Range<int>>);
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> test_outputs<std::range_formatter>();
>> test_outputs<VectorFormatter>();
>> @@ -179,4 +193,15 @@ int main()
>> test_nonblocking<std::span>();
>> test_nonblocking<std::vector>();
>> test_nonblocking<MyVector>();
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
>> b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
>> index 7fb65f9c551..da1fe7e0df7 100644
>> --- a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
>> +++ b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
>> @@ -1,7 +1,13 @@
>> // { dg-do run { target c++23 } }
>> -// { dg-options "-fexec-charset=UTF-8" }
>> +// { dg-options "-fexec-charset=UTF-8 -fconstexpr-ops-limit=5000000000" }
>> // { dg-timeout-factor 2 }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <array>
>> #include <format>
>> #include <list>
>> @@ -19,7 +25,7 @@
>> static_assert(!std::formattable<std::vector<NotFormattable>, char>);
>> static_assert(!std::formattable<std::span<NotFormattable>, wchar_t>);
>>
>> template<typename... Args>
>> -bool
>> +constexpr26 bool
>> is_format_string_for(const char* str, Args&&... args)
>> {
>> try {
>> @@ -31,7 +37,7 @@ is_format_string_for(const char* str, Args&&... args)
>> }
>>
>> template<typename... Args>
>> -bool
>> +constexpr26 bool
>> is_format_string_for(const wchar_t* str, Args&&... args)
>> {
>> try {
>> @@ -43,7 +49,8 @@ is_format_string_for(const wchar_t* str, Args&&... args)
>> }
>>
>> template<typename Rg, typename CharT>
>> -bool is_range_formatter_spec_for(CharT const* spec, Rg&& rg)
>> +constexpr26 bool
>> +is_range_formatter_spec_for(CharT const* spec, Rg&& rg)
>> {
>> using V = std::remove_cvref_t<std::ranges::range_reference_t<Rg>>;
>> std::range_formatter<V, CharT> fmt;
>> @@ -56,6 +63,7 @@ bool is_range_formatter_spec_for(CharT const* spec,
>> Rg&& rg)
>> }
>> }
>>
>> +// not constexpr because of PR124145
>> void
>> test_format_string()
>> {
>> @@ -79,7 +87,8 @@ test_format_string()
>> #define WIDEN(S) WIDEN_(CharT, S)
>>
>> template<typename CharT, typename Range, typename Storage>
>> -void test_output()
>> +constexpr26 void
>> +test_output()
>> {
>> using Sv = std::basic_string_view<CharT>;
>> using T = std::ranges::range_value_t<Range>;
>> @@ -153,25 +162,32 @@ void test_output()
>> }
>>
>> template<typename Cont>
>> -void test_output_cont()
>> +constexpr26 void
>> +test_output_cont()
>> {
>> test_output<char, Cont&, Cont>();
>> - test_output<wchar_t, Cont const&, Cont>();
>> + if (!std::is_constant_evaluated())
>> + test_output<wchar_t, Cont const&, Cont>();
>> }
>>
>> template<typename View>
>> -void test_output_view()
>> +constexpr26 void
>> +test_output_view()
>> {
>> test_output<char, View, int[3]>();
>> - test_output<wchar_t, View, int[3]>();
>> + if (!std::is_constant_evaluated())
>> + test_output<wchar_t, View, int[3]>();
>> }
>>
>> -void
>> +constexpr26 void
>> test_outputs()
>> {
>> using namespace __gnu_test;
>> test_output_cont<std::vector<int>>();
>> - test_output_cont<std::list<int>>();
>> +
>> + if (!std::is_constant_evaluated())
>> + test_output_cont<std::list<int>>();
>> +
>> test_output_cont<std::array<int, 3>>();
>>
>> test_output_view<std::span<int>>();
>> @@ -185,7 +201,7 @@ test_outputs()
>> test_output_view<test_forward_range<const int>>();
>> }
>>
>> -void
>> +constexpr26 void
>> test_nested()
>> {
>> std::vector<std::vector<int>> v
>> @@ -201,7 +217,8 @@ test_nested()
>> VERIFY( res == "+[01, 02, 11, 12]+" );
>> }
>>
>> -bool strip_quote(std::string_view& v)
>> +constexpr26 bool
>> +strip_quote(std::string_view& v)
>> {
>> if (!v.starts_with('"'))
>> return false;
>> @@ -209,7 +226,8 @@ bool strip_quote(std::string_view& v)
>> return true;
>> }
>>
>> -bool strip_prefix(std::string_view& v, std::string_view expected, bool
>> quoted = false)
>> +constexpr26 bool
>> +strip_prefix(std::string_view& v, std::string_view expected, bool quoted
>> = false)
>> {
>> if (quoted && !strip_quote(v))
>> return false;
>> @@ -221,7 +239,8 @@ bool strip_prefix(std::string_view& v,
>> std::string_view expected, bool quoted =
>> return true;
>> }
>>
>> -bool strip_squares(std::string_view& v)
>> +constexpr26 bool
>> +strip_squares(std::string_view& v)
>> {
>> if (!v.starts_with('[') || !v.ends_with(']'))
>> return false;
>> @@ -230,7 +249,8 @@ bool strip_squares(std::string_view& v)
>> return true;
>> }
>>
>> -bool strip_prefix(std::string_view& v, size_t n, char c)
>> +constexpr26 bool
>> +strip_prefix(std::string_view& v, size_t n, char c)
>> {
>> size_t pos = v.find_first_not_of(c);
>> if (pos == std::string_view::npos)
>> @@ -241,7 +261,8 @@ bool strip_prefix(std::string_view& v, size_t n, char
>> c)
>> return true;
>> }
>>
>> -void test_padding()
>> +constexpr26 void
>> +test_padding()
>> {
>> std::string res;
>> std::string_view resv;
>> @@ -323,10 +344,24 @@ void test_padding()
>> VERIFY( check_elems(resv, false) );
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> - test_format_string();
>> test_outputs();
>> test_nested();
>> test_padding();
>> +
>> + if (!std::is_constant_evaluated())
>> + test_format_string();
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/runtime_format.cc
>> b/libstdc++-v3/testsuite/std/format/runtime_format.cc
>> index f2bfa5b434d..6bb402a4108 100644
>> --- a/libstdc++-v3/testsuite/std/format/runtime_format.cc
>> +++ b/libstdc++-v3/testsuite/std/format/runtime_format.cc
>> @@ -3,7 +3,7 @@
>> #include <format>
>> #include <testsuite_hooks.h>
>>
>> -void
>> +constexpr void
>> test_char()
>> {
>> std::string fmt = "{}";
>> @@ -19,7 +19,7 @@ test_wchar()
>> VERIFY( s == L"0710" );
>> }
>>
>> -void
>> +constexpr void
>> test_internal_api()
>> {
>> // Using _Runtime_format_string directly works even in C++20 mode.
>> @@ -40,9 +40,19 @@ static_assert(
>> !std::is_constructible_v<std::format_string<>,
>> static_assert( !std::is_constructible_v<std::wformat_string<>,
>>
>> decltype(std::runtime_format(L""))&&> );
>>
>> -int main()
>> +constexpr bool
>> +test_all()
>> {
>> test_char();
>> - test_wchar();
>> + if (!std::is_constant_evaluated())
>> + test_wchar();
>> test_internal_api();
>> + return true;
>> +}
>> +
>> +static_assert(test_all());
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/string.cc
>> b/libstdc++-v3/testsuite/std/format/string.cc
>> index ee987a15ec3..90222db90aa 100644
>> --- a/libstdc++-v3/testsuite/std/format/string.cc
>> +++ b/libstdc++-v3/testsuite/std/format/string.cc
>> @@ -1,10 +1,16 @@
>> // { dg-do run { target c++20 } }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <format>
>> #include <testsuite_hooks.h>
>>
>> template<typename... Args>
>> -bool
>> +constexpr26 bool
>> is_format_string_for(const char* str, Args&&... args)
>> {
>> try {
>> @@ -16,7 +22,7 @@ is_format_string_for(const char* str, Args&&... args)
>> }
>>
>> template<typename... Args>
>> -bool
>> +constexpr26 bool
>> is_format_string_for(const wchar_t* str, Args&&... args)
>> {
>> try {
>> @@ -27,28 +33,37 @@ is_format_string_for(const wchar_t* str, Args&&...
>> args)
>> }
>> }
>>
>> -void
>> +constexpr26 void
>> test_no_args()
>> {
>> VERIFY( is_format_string_for("") );
>> VERIFY( is_format_string_for("chars") );
>> VERIFY( is_format_string_for(" The Great Escape {{}} ") );
>>
>> - VERIFY( ! is_format_string_for("{") );
>> - VERIFY( ! is_format_string_for("}") );
>> - VERIFY( ! is_format_string_for("}{") );
>> - VERIFY( ! is_format_string_for("{{}") );
>> - VERIFY( ! is_format_string_for("{{{") );
>> - VERIFY( ! is_format_string_for("{{{{{") );
>> + // not constexpr because of PR124145
>> + if (!std::is_constant_evaluated())
>> + {
>> + VERIFY( ! is_format_string_for("{") );
>> + VERIFY( ! is_format_string_for("}") );
>> + VERIFY( ! is_format_string_for("}{") );
>> + VERIFY( ! is_format_string_for("{{}") );
>> + VERIFY( ! is_format_string_for("{{{") );
>> + VERIFY( ! is_format_string_for("{{{{{") );
>> + }
>> }
>>
>> -void
>> +constexpr26 void
>> test_indexing()
>> {
>> VERIFY( is_format_string_for("{} to {}", "a", "b") ); // automatic
>> indexing
>> VERIFY( is_format_string_for("{1} to {0}", "a", "b") ); // manual
>> indexing
>> - VERIFY( ! is_format_string_for("{0} to {}", "a", "b") ); // mixed
>> indexing
>> - VERIFY( ! is_format_string_for("{} to {1}", "a", "b") ); // mixed
>> indexing
>> +
>> + // not constexpr because of PR124145
>> + if (!std::is_constant_evaluated())
>> + {
>> + VERIFY( ! is_format_string_for("{0} to {}", "a", "b") ); // mixed
>> indexing
>> + VERIFY( ! is_format_string_for("{} to {1}", "a", "b") ); // mixed
>> indexing
>> + }
>>
>> VERIFY( is_format_string_for("{} {} {}", 1, 2, 3) );
>> VERIFY( is_format_string_for("{} {} {}", 1, 2, 3, 4) );
>> @@ -56,10 +71,14 @@ test_indexing()
>> VERIFY( is_format_string_for("{1} {2} {3}", 1, 2, 3, 4) );
>> VERIFY( is_format_string_for("{3} {3} {3}", 1, 2, 3, 4) );
>>
>> - VERIFY( ! is_format_string_for("{2}", 1, 2) );
>> + // not constexpr because of PR124145
>> + if (!std::is_constant_evaluated())
>> + {
>> + VERIFY( ! is_format_string_for("{2}", 1, 2) );
>>
>> - VERIFY( ! is_format_string_for("{0} {}", 1) );
>> - VERIFY( ! is_format_string_for("{} {0}", 1) );
>> + VERIFY( ! is_format_string_for("{0} {}", 1) );
>> + VERIFY( ! is_format_string_for("{} {0}", 1) );
>> + }
>> }
>>
>> #if __cpp_lib_format_ranges
>> @@ -68,7 +87,7 @@ constexpr bool escaped_strings_supported = true;
>> constexpr bool escaped_strings_supported = false;
>> #endif
>>
>> -void
>> +constexpr26 void
>> test_format_spec()
>> {
>> VERIFY( is_format_string_for("{:}", 1) );
>> @@ -78,92 +97,114 @@ test_format_spec()
>> VERIFY( is_format_string_for("{0:} {0:c}", 'c') );
>> VERIFY( is_format_string_for("{0:p} {0:}", nullptr) );
>> VERIFY( is_format_string_for("{:d} {:+d}", true, true) );
>> - VERIFY( is_format_string_for("{:0<-#03Ld}", 1) );
>> - VERIFY( is_format_string_for("{1:0<-#03.4Lf}", 1, 2.3) );
>> - VERIFY( is_format_string_for("{1:3.3f}", 1, 2.3) );
>> +
>> + if (!std::is_constant_evaluated())
>> + {
>> + VERIFY( is_format_string_for("{:0<-#03Ld}", 1) );
>> + VERIFY( is_format_string_for("{1:0<-#03.4Lf}", 1, 2.3) );
>> + VERIFY( is_format_string_for("{1:3.3f}", 1, 2.3) );
>> + }
>> +
>> VERIFY( is_format_string_for("{:#d}", 'c') );
>> VERIFY( is_format_string_for("{:#d}", true) );
>> VERIFY( is_format_string_for("{0:s} {0:?}", "str") ==
>> escaped_strings_supported );
>> VERIFY( is_format_string_for("{0:} {0:?}", 'c') ==
>> escaped_strings_supported );
>>
>> - // Invalid sign options.
>> - VERIFY( ! is_format_string_for("{:+}", "str") );
>> - VERIFY( ! is_format_string_for("{:+s}", "str") );
>> - VERIFY( ! is_format_string_for("{:+}", 'c') );
>> - VERIFY( ! is_format_string_for("{:+c}", 'c') );
>> - VERIFY( ! is_format_string_for("{:+p}", nullptr) );
>> - VERIFY( ! is_format_string_for("{:+}", true) );
>> - VERIFY( ! is_format_string_for("{:+s}", true) );
>> - VERIFY( ! is_format_string_for("{:+?}", "str") );
>> - VERIFY( ! is_format_string_for("{:+?}", 'c') );
>> -
>> - // Invalid alternate forms.
>> - VERIFY( ! is_format_string_for("{:#}", "str") );
>> - VERIFY( ! is_format_string_for("{:#s}", "str") );
>> - VERIFY( ! is_format_string_for("{:#}", 'c') );
>> - VERIFY( ! is_format_string_for("{:#c}", 'c') );
>> - VERIFY( ! is_format_string_for("{:#}", true) );
>> - VERIFY( ! is_format_string_for("{:#s}", true) );
>> - VERIFY( ! is_format_string_for("{:#}", nullptr) );
>> - VERIFY( ! is_format_string_for("{:#p}", nullptr) );
>> - VERIFY( ! is_format_string_for("{:#?}", "str") );
>> - VERIFY( ! is_format_string_for("{:#?}", 'c') );
>> -
>> - // The 0 option is not valid for charT and bool.
>> - VERIFY( ! is_format_string_for("{:0c}", 'c') );
>> - VERIFY( ! is_format_string_for("{:0s}", true) );
>> -
>> - // Dynamic width arg must be a standar integer type.
>> - VERIFY( ! is_format_string_for("{:{}d}", 1, 1.5) );
>> - VERIFY( ! is_format_string_for("{:{}d}", 1, true) );
>> - VERIFY( ! is_format_string_for("{:{}d}", 1, "str") );
>> - VERIFY( ! is_format_string_for("{:{}d}", 1, nullptr) );
>> + // not constexpr because of PR124145
>> + if (!std::is_constant_evaluated())
>> + {
>> + // Invalid sign options.
>> + VERIFY( ! is_format_string_for("{:+}", "str") );
>> + VERIFY( ! is_format_string_for("{:+s}", "str") );
>> + VERIFY( ! is_format_string_for("{:+}", 'c') );
>> + VERIFY( ! is_format_string_for("{:+c}", 'c') );
>> + VERIFY( ! is_format_string_for("{:+p}", nullptr) );
>> + VERIFY( ! is_format_string_for("{:+}", true) );
>> + VERIFY( ! is_format_string_for("{:+s}", true) );
>> + VERIFY( ! is_format_string_for("{:+?}", "str") );
>> + VERIFY( ! is_format_string_for("{:+?}", 'c') );
>> +
>> + // Invalid alternate forms.
>> + VERIFY( ! is_format_string_for("{:#}", "str") );
>> + VERIFY( ! is_format_string_for("{:#s}", "str") );
>> + VERIFY( ! is_format_string_for("{:#}", 'c') );
>> + VERIFY( ! is_format_string_for("{:#c}", 'c') );
>> + VERIFY( ! is_format_string_for("{:#}", true) );
>> + VERIFY( ! is_format_string_for("{:#s}", true) );
>> + VERIFY( ! is_format_string_for("{:#}", nullptr) );
>> + VERIFY( ! is_format_string_for("{:#p}", nullptr) );
>> + VERIFY( ! is_format_string_for("{:#?}", "str") );
>> + VERIFY( ! is_format_string_for("{:#?}", 'c') );
>> +
>> + // The 0 option is not valid for charT and bool.
>> + VERIFY( ! is_format_string_for("{:0c}", 'c') );
>> + VERIFY( ! is_format_string_for("{:0s}", true) );
>> +
>> + // Dynamic width arg must be a standar integer type.
>> + VERIFY( ! is_format_string_for("{:{}d}", 1, 1.5) );
>> + VERIFY( ! is_format_string_for("{:{}d}", 1, true) );
>> + VERIFY( ! is_format_string_for("{:{}d}", 1, "str") );
>> + VERIFY( ! is_format_string_for("{:{}d}", 1, nullptr) );
>> #ifdef __SIZEOF_INT128__
>> - VERIFY( ! is_format_string_for("{:{}d}", 1, static_cast<__int128>(1))
>> );
>> + VERIFY( ! is_format_string_for("{:{}d}", 1,
>> static_cast<__int128>(1)) );
>> #endif
>>
>> - // Precision only valid for string and floating-point types.
>> - VERIFY( ! is_format_string_for("{:.3d}", 1) );
>> - VERIFY( ! is_format_string_for("{:3.3d}", 1) );
>> + // Precision only valid for string and floating-point types.
>> + VERIFY( ! is_format_string_for("{:.3d}", 1) );
>> + VERIFY( ! is_format_string_for("{:3.3d}", 1) );
>> + }
>> +
>> VERIFY( is_format_string_for("{:3.3s}", "str") );
>> - VERIFY( ! is_format_string_for("{:3.3s}", 'c') );
>> - VERIFY( ! is_format_string_for("{:3.3p}", nullptr) );
>> -
>> - // Dynamic precision arg must be a standard integer type.
>> - VERIFY( ! is_format_string_for("{:.{}f}", 1.0, 1.5) );
>> - VERIFY( ! is_format_string_for("{:.{}f}", 1.0, true) );
>> - VERIFY( ! is_format_string_for("{:.{}f}", 1.0, "str") );
>> - VERIFY( ! is_format_string_for("{:.{}f}", 1.0, nullptr) );
>> +
>> + // not constexpr because of PR124145
>> + if (!std::is_constant_evaluated())
>> + {
>> + VERIFY( ! is_format_string_for("{:3.3s}", 'c') );
>> + VERIFY( ! is_format_string_for("{:3.3p}", nullptr) );
>> +
>> + // Dynamic precision arg must be a standard integer type.
>> + VERIFY( ! is_format_string_for("{:.{}f}", 1.0, 1.5) );
>> + VERIFY( ! is_format_string_for("{:.{}f}", 1.0, true) );
>> + VERIFY( ! is_format_string_for("{:.{}f}", 1.0, "str") );
>> + VERIFY( ! is_format_string_for("{:.{}f}", 1.0, nullptr) );
>> #ifdef __SIZEOF_INT128__
>> - VERIFY( ! is_format_string_for("{:{}f}", 1.0, static_cast<unsigned
>> __int128>(1)) );
>> + VERIFY( ! is_format_string_for("{:{}f}", 1.0, static_cast<unsigned
>> __int128>(1)) );
>> #endif
>>
>> - // Invalid presentation types for integers.
>> - VERIFY( ! is_format_string_for("{:f}", 1) );
>> - VERIFY( ! is_format_string_for("{:s}", 1) );
>> - VERIFY( ! is_format_string_for("{:g}", 1) );
>> - VERIFY( ! is_format_string_for("{:E}", 1) );
>> - VERIFY( ! is_format_string_for("{:D}", 1) );
>> + // Invalid presentation types for integers.
>> + VERIFY( ! is_format_string_for("{:f}", 1) );
>> + VERIFY( ! is_format_string_for("{:s}", 1) );
>> + VERIFY( ! is_format_string_for("{:g}", 1) );
>> + VERIFY( ! is_format_string_for("{:E}", 1) );
>> + VERIFY( ! is_format_string_for("{:D}", 1) );
>>
>> - // Invalid presentation types for floating-point types.
>> - VERIFY( ! is_format_string_for("{:d}", 1.2) );
>> - VERIFY( ! is_format_string_for("{:b}", 1.2) );
>> - VERIFY( ! is_format_string_for("{:x}", 1.2) );
>> - VERIFY( ! is_format_string_for("{:s}", 1.2) );
>> + // Invalid presentation types for floating-point types.
>> + VERIFY( ! is_format_string_for("{:d}", 1.2) );
>> + VERIFY( ! is_format_string_for("{:b}", 1.2) );
>> + VERIFY( ! is_format_string_for("{:x}", 1.2) );
>> + VERIFY( ! is_format_string_for("{:s}", 1.2) );
>>
>> - // Invalid presentation types for strings.
>> - VERIFY( ! is_format_string_for("{:S}", "str") );
>> - VERIFY( ! is_format_string_for("{:d}", "str") );
>> + // Invalid presentation types for strings.
>> + VERIFY( ! is_format_string_for("{:S}", "str") );
>> + VERIFY( ! is_format_string_for("{:d}", "str") );
>> + }
>>
>> // Maximum integer value supported for widths and precisions is
>> USHRT_MAX.
>> VERIFY( is_format_string_for("{:65535}", 1) );
>> - VERIFY( is_format_string_for(L"{:65535}", 1) );
>> - VERIFY( ! is_format_string_for("{:65536}", 1) );
>> - VERIFY( ! is_format_string_for(L"{:65536}", 1) );
>> - VERIFY( ! is_format_string_for("{:9999999}", 1) );
>> - VERIFY( ! is_format_string_for(L"{:9999999}", 1) );
>> +
>> + // constexpr wide formatting not yet implemented
>> + if (!std::is_constant_evaluated())
>> + {
>> + VERIFY( is_format_string_for(L"{:65535}", 1) );
>> + // PR124145
>> + VERIFY( ! is_format_string_for("{:65536}", 1) );
>> + VERIFY( ! is_format_string_for(L"{:65536}", 1) );
>> + VERIFY( ! is_format_string_for("{:9999999}", 1) );
>> + VERIFY( ! is_format_string_for(L"{:9999999}", 1) );
>> + }
>> }
>>
>> +// not constexpr because of PR124145
>> void
>> test_pr110862()
>> {
>> @@ -178,6 +219,7 @@ test_pr110862()
>> }
>> }
>>
>> +// not constexpr because of PR124145
>> void
>> test_pr110974()
>> {
>> @@ -197,11 +239,27 @@ test_pr110974()
>> }
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> test_no_args();
>> test_indexing();
>> test_format_spec();
>> - test_pr110862();
>> - test_pr110974();
>> +
>> + if (!std::is_constant_evaluated())
>> + {
>> + test_pr110862();
>> + test_pr110974();
>> + }
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> diff --git a/libstdc++-v3/testsuite/std/format/tuple.cc
>> b/libstdc++-v3/testsuite/std/format/tuple.cc
>> index eace82730f0..10e19149935 100644
>> --- a/libstdc++-v3/testsuite/std/format/tuple.cc
>> +++ b/libstdc++-v3/testsuite/std/format/tuple.cc
>> @@ -2,6 +2,12 @@
>> // { dg-options "-fexec-charset=UTF-8" }
>> // { dg-timeout-factor 2 }
>>
>> +#if __cplusplus >= 202400L
>> +# define constexpr26 constexpr
>> +#else
>> +# define constexpr26
>> +#endif
>> +
>> #include <format>
>> #include <string>
>> #include <testsuite_hooks.h>
>> @@ -15,7 +21,7 @@ static_assert( !std::formattable<std::pair<int,
>> NotFormattable>, char> );
>> static_assert( !std::formattable<std::tuple<int, NotFormattable, int>,
>> wchar_t> );
>>
>> template<typename... Args>
>> -bool
>> +constexpr26 bool
>> is_format_string_for(const char* str, Args&&... args)
>> {
>> try {
>> @@ -27,7 +33,7 @@ is_format_string_for(const char* str, Args&&... args)
>> }
>>
>> template<typename... Args>
>> -bool
>> +constexpr26 bool
>> is_format_string_for(const wchar_t* str, Args&&... args)
>> {
>> try {
>> @@ -41,6 +47,7 @@ is_format_string_for(const wchar_t* str, Args&&... args)
>> #define WIDEN_(C, S) ::std::__format::_Widen<C>(S, L##S)
>> #define WIDEN(S) WIDEN_(CharT, S)
>>
>> +// not constexpr because of PR124145
>> void
>> test_format_string()
>> {
>> @@ -123,7 +130,8 @@ void test_multi()
>> }
>>
>> template<typename CharT, typename Tuple>
>> -void test_empty()
>> +constexpr26 void
>> +test_empty()
>> {
>> std::basic_string<CharT> res;
>>
>> @@ -142,7 +150,8 @@ void test_empty()
>> }
>>
>> template<typename CharT, typename Pair>
>> -void test_pair()
>> +constexpr26 void
>> +test_pair()
>> {
>> using Ft = std::remove_cvref_t<std::tuple_element_t<0, Pair>>;
>> using St = std::remove_cvref_t<std::tuple_element_t<1, Pair>>;
>> @@ -167,7 +176,8 @@ void test_pair()
>> }
>>
>> template<typename CharT, template<typename, typename> class PairT>
>> -void test_pair_e()
>> +constexpr26 void
>> +test_pair_e()
>> {
>> test_pair<CharT, PairT<int, std::basic_string<CharT>>>();
>> test_pair<CharT, PairT<int, const CharT*>>();
>> @@ -196,7 +206,7 @@ struct std::formatter<MyPair<Pair>, CharT>
>> { return _formatter.parse(pc); }
>>
>> template<typename Out>
>> - typename std::basic_format_context<Out, CharT>::iterator
>> + constexpr26 typename std::basic_format_context<Out, CharT>::iterator
>> format(const MyPair<Pair>& mp,
>> std::basic_format_context<Out, CharT>& fc) const
>> { return _formatter.format(mp, fc); }
>> @@ -206,7 +216,8 @@ private:
>> };
>>
>> template<typename CharT, template<typename, typename> class PairT>
>> -void test_custom()
>> +constexpr26 void
>> +test_custom()
>> {
>> std::basic_string<CharT> res;
>> MyPair<PairT<int, const CharT*>> c1(1, WIDEN("abc"));
>> @@ -228,9 +239,12 @@ void test_custom()
>> }
>>
>> template<typename CharT>
>> -void test_outputs()
>> +constexpr26 void
>> +test_outputs()
>> {
>> - test_multi<CharT>();
>> + if (!std::is_constant_evaluated())
>> + test_multi<CharT>();
>> +
>> test_empty<CharT, std::tuple<>>();
>> test_pair_e<CharT, std::pair>();
>> test_pair_e<CharT, std::tuple>();
>> @@ -238,7 +252,8 @@ void test_outputs()
>> test_custom<CharT, std::tuple>();
>> }
>>
>> -void test_nested()
>> +constexpr26 void
>> +test_nested()
>> {
>> std::string res;
>> std::tuple<std::tuple<>, std::pair<int, std::string>> tt{{}, {1,
>> "abc"}};
>> @@ -251,7 +266,8 @@ void test_nested()
>> VERIFY( res == R"((): (1, "abc"))" );
>> }
>>
>> -bool strip_quote(std::string_view& v)
>> +constexpr26 bool
>> +strip_quote(std::string_view& v)
>> {
>> if (!v.starts_with('"'))
>> return false;
>> @@ -259,7 +275,8 @@ bool strip_quote(std::string_view& v)
>> return true;
>> }
>>
>> -bool strip_prefix(std::string_view& v, std::string_view expected, bool
>> quoted = false)
>> +constexpr26 bool
>> +strip_prefix(std::string_view& v, std::string_view expected, bool quoted
>> = false)
>> {
>> if (quoted && !strip_quote(v))
>> return false;
>> @@ -271,7 +288,8 @@ bool strip_prefix(std::string_view& v,
>> std::string_view expected, bool quoted =
>> return true;
>> }
>>
>> -bool strip_parens(std::string_view& v)
>> +constexpr26 bool
>> +strip_parens(std::string_view& v)
>> {
>> if (!v.starts_with('(') || !v.ends_with(')'))
>> return false;
>> @@ -280,7 +298,8 @@ bool strip_parens(std::string_view& v)
>> return true;
>> }
>>
>> -bool strip_prefix(std::string_view& v, size_t n, char c)
>> +constexpr26 bool
>> +strip_prefix(std::string_view& v, size_t n, char c)
>> {
>> size_t pos = v.find_first_not_of(c);
>> if (pos == std::string_view::npos)
>> @@ -291,7 +310,8 @@ bool strip_prefix(std::string_view& v, size_t n, char
>> c)
>> return true;
>> }
>>
>> -void test_padding()
>> +constexpr26 void
>> +test_padding()
>> {
>> std::string res;
>> std::string_view resv;
>> @@ -351,13 +371,14 @@ struct std::formatter<Custom, CharT>
>> { return pc.begin(); }
>>
>> template<typename Out>
>> - typename std::basic_format_context<Out, CharT>::iterator
>> + constexpr26 typename std::basic_format_context<Out, CharT>::iterator
>> format(Custom, const std::basic_format_context<Out, CharT>& fc) const
>> { return fc.out(); }
>> };
>>
>> template<template<typename...> typename Tuple>
>> -void test_nonblocking()
>> +constexpr26 void
>> +test_nonblocking()
>> {
>> static_assert(std::enable_nonlocking_formatter_optimization<
>> Tuple<int, float>>);
>> @@ -374,14 +395,31 @@ void test_nonblocking()
>> Tuple<Custom&, float&>>);
>> }
>>
>> -int main()
>> +constexpr26 bool
>> +test_all()
>> {
>> - test_format_string();
>> test_outputs<char>();
>> - test_outputs<wchar_t>();
>> test_nested();
>> test_padding();
>>
>> test_nonblocking<std::pair>();
>> test_nonblocking<std::tuple>();
>> +
>> + if (!std::is_constant_evaluated())
>> + {
>> + test_format_string();
>> + // constexpr wide formatting not yet implemented
>> + test_outputs<wchar_t>();
>> + }
>> +
>> + return true;
>> +}
>> +
>> +#if __cplusplus >= 202400L
>> +static_assert(test_all());
>> +#endif
>> +
>> +int main()
>> +{
>> + test_all();
>> }
>> --
>> 2.43.0
>>
>>
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