On Wed, Apr 16, 2025 at 11:17 AM Jonathan Wakely <jwak...@redhat.com> wrote:
> On 16/04/25 09:13 +0200, Tomasz Kamiński wrote:
> >This patch implements formatter specializations for pair and tuple form
> >P2286R8. In addition using 'm` and range_format::map (from P2585R1) for
> >ranges are now supported.
> >
> >The formatters for pairs and tuples whose corresponding elements are the
> same
> >(after applying remove_cvref_t) derive from the same __tuple_formatter
> class.
> >This reduce the code duplication, as most of the parsing and formatting
> is the
> >same in such cases. We use a custom reduced implementation of the tuple
> >(__formatters_storage) to store the elements formatters.
>
> This is a nice solution, the code for __formatters_storage and
> __indexed_formatter_storage is clear and concise.
>
> >Handling of the padding (width and fill) options, is extracted to
> >__format::__format_padded function, that is used both by
> __tuple_formatter and
> >range_formatter. To reduce number of instantations range_formatter::format
> >triggers, we cast incoming range to __format::__maybe_const_range<_Rg,
> _CharT>&,
> >before formatting it.
> >
> >As in the case of previous commits, the signatures of the user-facing
> parse
> >and format methods of the provided formatters deviate from the standard by
> >constraining types of parameters:
> >* _CharT is constrained __formatter::__char
> >* basic_format_parse_context<_CharT> for parse argument
> >* basic_format_context<_Out, _CharT> for format second argument
> >The standard specifies last three of above as unconstrained types.
> >
> >Finally, test for tuple-like std::array and std::ranges::subrange,
> >that illustrate that they remain formatted as ranges.
> >
> > PR libstdc++/PR109162
> >
> >libstdc++-v3/ChangeLog:
> >
> > * include/std/format (__formatter_int::_M_format_character_escaped)
> > (__formatter_str::format): Use __sink.out() to produce _Sink_iter.
> > (__format::__format_padded, __format::maybe_const)
> > (__format::__indexed_formatter_storage,
> __format::__tuple_formatter)
> > (std::formatter<pair<_Fp, _Sp>, _CharT>>)
> > (std::formatter<tuple<_Tps...>, _CharT): Define.
> > (std::formatter<_Rg, _CharT>::format): Cast incoming range to
> > __format::__maybe_const_range<_Rg, _CharT>&.
> > (std::formatter<_Rg, _CharT>::_M_format): Extracted from format,
> > and use __format_padded.
> > (std::formatter<_Rg, _CharT>::_M_format_no_padding): Rename...
> > (std::formatter<_Rg, _CharT>::_M_format_elems): ...to this.
> > (std::formatter<_Rg, _CharT>::_M_format_with_padding): Extracted as
> > __format_padded.
> > * testsuite/util/testsuite_iterators.h (test_input_range_nocopy):
> > Define.
> > * testsuite/std/format/ranges/formatter.cc: Tests for `m`
> specifier.
> > * testsuite/std/format/ranges/sequence.cc: Tests for array and
> subrange.
> > * testsuite/std/format/ranges/map.cc: New test.
> > * testsuite/std/format/tuple.cc: New test.
> >---
> >Testing on x86_64-linux, tests matched by `*format*` passes.
> >OK for trunk? Should I wait for 16?
>
> A few minor comments below ...
>
> > libstdc++-v3/include/std/format | 357 +++++++++++++++---
> > .../testsuite/std/format/ranges/formatter.cc | 6 +-
> > .../testsuite/std/format/ranges/map.cc | 209 ++++++++++
> > .../testsuite/std/format/ranges/sequence.cc | 52 ++-
> > libstdc++-v3/testsuite/std/format/tuple.cc | 259 +++++++++++++
> > .../testsuite/util/testsuite_iterators.h | 3 +
> > 6 files changed, 806 insertions(+), 80 deletions(-)
> > create mode 100644 libstdc++-v3/testsuite/std/format/ranges/map.cc
> > create mode 100644 libstdc++-v3/testsuite/std/format/tuple.cc
> >
> >diff --git a/libstdc++-v3/include/std/format
> b/libstdc++-v3/include/std/format
> >index 096dda4f989..5b93eb8bc2d 100644
> >--- a/libstdc++-v3/include/std/format
> >+++ b/libstdc++-v3/include/std/format
> >@@ -1350,8 +1350,7 @@ namespace __format
> > __fc, _M_spec);
> >
> > __format::_Str_sink<_CharT> __sink;
> >- __format::_Sink_iter<_CharT> __out(__sink);
> >- __format::__write_escaped(__out, __s, __term);
> >+ __format::__write_escaped(__sink.out(), __s, __term);
> > basic_string_view<_CharT> __escaped(__sink.view().data(),
> > __sink.view().size());
> > const size_t __escaped_width = _S_trunc(__escaped, __prec);
> >@@ -1387,13 +1386,13 @@ namespace __format
> > {
> > ranges::iterator_t<_Rg> __first = ranges::begin(__rg);
> > ranges::subrange __sub(__first, __first + __n);
> >- return format(_String(from_range, __sub), __fc);
> >+ return format(_String(from_range, __sub), __fc);
> > }
> > else
> > {
> > // N.B. preserve the computed size
> > ranges::subrange __sub(__rg, __n);
> >- return format(_String(from_range, __sub), __fc);
> >+ return format(_String(from_range, __sub), __fc);
> > }
> > }
> > else
> >@@ -1698,7 +1697,7 @@ namespace __format
> > template<typename _Out>
> > typename basic_format_context<_Out, _CharT>::iterator
> > _M_format_character_escaped(_CharT __c,
> >- basic_format_context<_Out, _CharT>&
> __fc) const
> >+ basic_format_context<_Out, _CharT>&
> __fc) const
> > {
> > using _Esc = _Escapes<_CharT>;
> > constexpr auto __term = __format::_Term_char::_Tc_apos;
> >@@ -1708,8 +1707,7 @@ namespace __format
> >
> > _CharT __buf[12];
> > __format::_Fixedbuf_sink<_CharT> __sink(__buf);
> >- __format::_Sink_iter<_CharT> __out(__sink);
> >- __format::__write_escaped(__out, __in, __term);
> >+ __format::__write_escaped(__sink.out(), __in, __term);
> >
> > const basic_string_view<_CharT> __escaped = __sink.view();
> > size_t __estimated_width;
> >@@ -5209,6 +5207,237 @@ namespace __format
> > /// @cond undocumented
> > namespace __format
> > {
> >+ template<typename _CharT, typename _Out, typename _Callback>
> >+ typename basic_format_context<_Out, _CharT>::iterator
> >+ __format_padded(basic_format_context<_Out, _CharT>& __fc,
> >+ const _Spec<_CharT>& __spec,
> >+ _Callback&& __call)
> >+ {
> >+ // This is required to implement formatting with padding,
> >+ // as we need to format to temporary buffer, using the same
> iterator.
> >+ static_assert(is_same_v<_Out, __format::_Sink_iter<_CharT>>);
> >+
> >+ if (__spec._M_get_width(__fc) == 0)
> >+ return __call(__fc);
> >+
> >+ struct _Restore_out
> >+ {
> >+ _Restore_out(basic_format_context<_Sink_iter<_CharT>, _CharT>&
> __fc)
> >+ : _M_ctx(addressof(__fc)), _M_out(__fc.out())
> >+ { }
> >+
> >+ void trigger()
> >+ {
> >+ if (_M_ctx)
> >+ _M_ctx->advance_to(_M_out);
> >+ _M_ctx = nullptr;
> >+ }
> >+
> >+ ~_Restore_out()
> >+ { trigger(); }
> >+
> >+ private:
> >+ basic_format_context<_Sink_iter<_CharT>, _CharT>* _M_ctx;
> >+ _Sink_iter<_CharT> _M_out;
> >+ };
> >+
> >+ _Restore_out __restore(__fc);
> >+ // TODO Consider double sinking, first buffer of width
> >+ // size and then original sink, if first buffer is overun
> >+ // we do not need to align
> >+ _Str_sink<_CharT> __buf;
> >+ __fc.advance_to(__buf.out());
> >+ __call(__fc);
> >+ __restore.trigger();
> >+
> >+ basic_string_view<_CharT> __str(__buf.view());
> >+ size_t __width;
> >+ if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
> >+ __width = __unicode::__field_width(__str);
> >+ else
> >+ __width = __str.size();
> >+
> >+ return __format::__write_padded_as_spec(__str, __width, __fc,
> __spec);
> >+ }
> >+
> >+ template<typename _Tp, typename _CharT>
> >+ using __maybe_const
> >+ = conditional_t<formattable<const _Tp, _CharT>, const _Tp, _Tp>;
>
> __conditional_t is cheaper to instantiate than std::conditional_t.
>
I wil apply this also to __maybe_const_range.
>
> >+
> >+ template<size_t _Pos, typename _Tp, typename _CharT>
> >+ struct __indexed_formatter_storage : formatter<_Tp, _CharT>
> >+ {
> >+ constexpr void
> >+ _M_parse()
> >+ {
> >+ basic_format_parse_context<_CharT> __pc({});
> >+ if (_M_formatter.parse(__pc) != __pc.end())
> >+ __format::__failed_to_parse_format_spec();
> >+ }
> >+
> >+ template<typename _Out>
> >+ void
> >+ _M_format(__maybe_const<_Tp, _CharT>& __elem,
> >+ basic_format_context<_Out, _CharT>& __fc,
> >+ basic_string_view<_CharT> __sep) const
> >+ {
> >+ if constexpr (_Pos != 0)
> >+ __fc.advance_to(__format::__write(__fc.out(), __sep));
> >+ __fc.advance_to(_M_formatter.format(__elem, __fc));
> >+ }
> >+
> >+ [[__gnu__::__always_inline__]]
> >+ constexpr void
> >+ set_debug_format()
> >+ {
> >+ if constexpr (__has_debug_format<formatter<_Tp, _CharT>>)
> >+ _M_formatter.set_debug_format();
> >+ }
> >+
> >+ private:
> >+ formatter<_Tp, _CharT> _M_formatter;
> >+ };
> >+
> >+ template<typename _CharT, typename... _Tps>
> >+ class __tuple_formatter
> >+ {
> >+ using _String_view = basic_string_view<_CharT>;
> >+ using _Seps = __format::_Separators<_CharT>;
> >+
> >+ public:
> >+ constexpr void
> >+ set_separator(basic_string_view<_CharT> __sep) noexcept
> >+ { _M_sep = __sep; }
> >+
> >+ constexpr void
> >+ set_brackets(basic_string_view<_CharT> __open,
> >+ basic_string_view<_CharT> __close) noexcept
> >+ {
> >+ _M_open = __open;
> >+ _M_close = __close;
> >+ }
> >+
> >+ // We deviate from standard, that declares this as template
> accepting
> >+ // unconstrained ParseContext type, which seems unimplementable.
> >+ constexpr typename basic_format_parse_context<_CharT>::iterator
> >+ parse(basic_format_parse_context<_CharT>& __pc)
> >+ {
> >+ auto __first = __pc.begin();
> >+ const auto __last = __pc.end();
> >+ __format::_Spec<_CharT> __spec{};
> >+
> >+ auto __finished = [&]
> >+ {
> >+ if (__first != __last && *__first != '}')
> >+ return false;
> >+
> >+ _M_spec = __spec;
> >+ _M_felems._M_parse();
> >+ _M_felems.set_debug_format();
> >+ return true;
> >+ };
> >+
> >+ if (__finished())
> >+ return __first;
> >+
> >+ __first = __spec._M_parse_fill_and_align(__first, __last, "{:");
> >+ if (__finished())
> >+ return __first;
> >+
> >+ __first = __spec._M_parse_width(__first, __last, __pc);
> >+ if (__finished())
> >+ return __first;
> >+
> >+ if (*__first == 'n')
> >+ {
> >+ ++__first;
> >+ _M_open = _M_close = _String_view();
> >+ }
> >+ else if (*__first == 'm')
> >+ {
> >+ ++__first;
> >+ if constexpr (sizeof...(_Tps) == 2)
> >+ {
> >+ _M_sep = _Seps::_S_colon();
> >+ _M_open = _M_close = _String_view();
> >+ }
> >+ else
> >+ __throw_format_error("format error: 'm' specifier requires
> range"
> >+ " of pair of tuple of two elements");
>
> s/pair of tuple/pair or tuple/
>
> >+ }
> >+
> >+ if (__finished())
> >+ return __first;
> >+
> >+ __format::__failed_to_parse_format_spec();
> >+ }
> >+
> >+ protected:
> >+ template<typename _Tuple, typename _Out, size_t... _Ids>
> >+ 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>
> >+ typename basic_format_context<_Out, _CharT>::iterator
> >+ _M_format_elems(__maybe_const<_Tps, _CharT>&... __elems,
> >+ basic_format_context<_Out, _CharT>& __fc) const
> >+ {
> >+ return __format::__format_padded(
> >+ __fc, _M_spec,
> >+ [this, &__elems...](basic_format_context<_Out, _CharT>&
> __nfc)
> >+ {
> >+ __nfc.advance_to(__format::__write(__nfc.out(),
> _M_open));
> >+ _M_felems._M_format(__elems..., __nfc, _M_sep);
> >+ return __format::__write(__nfc.out(), _M_close);
> >+ });
> >+ }
> >+
> >+ private:
> >+ template<size_t... _Ids>
> >+ struct __formatters_storage
> >+ : __indexed_formatter_storage<_Ids, _Tps, _CharT>...
> >+ {
> >+ template<size_t _Id, typename _Up>
> >+ using _Base = __indexed_formatter_storage<_Id, _Up, _CharT>;
> >+
> >+ constexpr void
> >+ _M_parse()
> >+ {
> >+ (_Base<_Ids, _Tps>::_M_parse(), ...);
> >+ }
> >+
> >+ template<typename _Out>
> >+ void
> >+ _M_format(__maybe_const<_Tps, _CharT>&... __elems,
> >+ basic_format_context<_Out, _CharT>& __fc,
> >+ _String_view __sep) const
> >+ {
> >+ (_Base<_Ids, _Tps>::_M_format(__elems, __fc, __sep), ...);
> >+ }
> >+
> >+ constexpr void
> >+ set_debug_format()
> >+ {
> >+ (_Base<_Ids, _Tps>::set_debug_format(), ...);
> >+ }
> >+ };
> >+
> >+ template<size_t... _Ids>
> >+ static auto
> >+ _S_create_storage(index_sequence<_Ids...>)
> >+ -> __formatters_storage<_Ids...>;
> >+ using _Formatters
> >+ = decltype(_S_create_storage(index_sequence_for<_Tps...>()));
> >+
> >+ _Spec<_CharT> _M_spec{};
> >+ _String_view _M_open = _Seps::_S_parens().substr(0, 1);
> >+ _String_view _M_close = _Seps::_S_parens().substr(1, 1);
> >+ _String_view _M_sep = _Seps::_S_comma();
> >+ _Formatters _M_felems;
> >+ };
> >+
> > template<typename _Tp>
> > concept __is_map_formattable
> > = __is_pair<_Tp> || (__is_tuple_v<_Tp> && tuple_size_v<_Tp> == 2);
> >@@ -5216,6 +5445,48 @@ namespace __format
> > } // namespace __format
> > /// @endcond
> >
> >+ // [format.tuple] Tuple formatter
> >+ template<__format::__char _CharT, formattable<_CharT> _Fp,
> >+ formattable<_CharT> _Sp>
> >+ struct formatter<pair<_Fp, _Sp>, _CharT>
> >+ : __format::__tuple_formatter<_CharT, remove_cvref_t<_Fp>,
> >+ remove_cvref_t<_Sp>>
> >+ {
> >+ private:
> >+ using __maybe_const_pair
> >+ = conditional_t<formattable<const _Fp, _CharT>
>
> This can use __conditional_t too.
>
> >+ && formattable<const _Sp, _CharT>,
> >+ const pair<_Fp, _Sp>, pair<_Fp, _Sp>>;
> >+ public:
> >+ // We deviate from standard, that declares this as template
> accepting
> >+ // unconstrained FormatContext type, which seems unimplementable.
> >+ template<typename _Out>
> >+ typename basic_format_context<_Out, _CharT>::iterator
> >+ format(__maybe_const_pair& __p,
> >+ basic_format_context<_Out, _CharT>& __fc) const
> >+ { return this->_M_format_elems(__p.first, __p.second, __fc); }
> >+ };
> >+
> >+ template<__format::__char _CharT, formattable<_CharT>... _Tps>
> >+ struct formatter<tuple<_Tps...>, _CharT>
> >+ : __format::__tuple_formatter<_CharT, remove_cvref_t<_Tps>...>
> >+ {
> >+ private:
> >+ using __maybe_const_tuple
> >+ = conditional_t<(formattable<const _Tps, _CharT> && ...),
>
> And here.
>
> >+ const tuple<_Tps...>, tuple<_Tps...>>;
> >+ public:
> >+ // We deviate from standard, that declares this as template
> accepting
> >+ // unconstrained FormatContext type, which seems unimplementable.
> >+ template<typename _Out>
> >+ typename basic_format_context<_Out, _CharT>::iterator
> >+ format(__maybe_const_tuple& __t,
> >+ basic_format_context<_Out, _CharT>& __fc) const
> >+ {
> >+ return this->_M_format(__t, index_sequence_for<_Tps...>(), __fc);
> >+ }
> >+ };
> >+
> > // [format.range.formatter], class template range_formatter
> > template<typename _Tp, __format::__char _CharT = char>
> > requires same_as<remove_cvref_t<_Tp>, _Tp> && formattable<_Tp,
> _CharT>
> >@@ -5369,9 +5640,16 @@ namespace __format
> > typename basic_format_context<_Out, _CharT>::iterator
> > format(_Rg&& __rg, basic_format_context<_Out, _CharT>& __fc) const
> > {
> >- // This is required to implement formatting with padding,
> >- // as we need to format to temporary buffer, using the same
> iterator.
> >- static_assert(is_same_v<_Out, __format::_Sink_iter<_CharT>>);
> >+ using __maybe_const_range
> >+ = __format::__maybe_const_range<_Rg, _CharT>;
> >+ return _M_format(static_cast<__maybe_const_range&>(__rg), __fc);
>
> Should this be const_cast not static_cast?
> It's either casting an _Rg lvalue to const _Rg& or _Rg&, right?
> If we don't need any type conversion, just potential cv-qualification,
> then I think const_cast is safer/clearer.
>
I connect const_cast with removing constness, which is not happening here.
So I always think of it as "less" safe.
>
> >+ }
> >+
> >+ private:
> >+ template<ranges::input_range _Rg, typename _Out>
> >+ typename basic_format_context<_Out, _CharT>::iterator
> >+ _M_format(_Rg& __rg, basic_format_context<_Out, _CharT>& __fc)
> const
> >+ {
> > if constexpr (same_as<_Tp, _CharT>)
> > if (_M_spec._M_type == __format::_Pres_str
> > || _M_spec._M_type == __format::_Pres_esc)
> >@@ -5379,16 +5657,17 @@ namespace __format
> > __format::__formatter_str __fstr(_M_spec);
> > return __fstr._M_format_range(__rg, __fc);
> > }
> >- if (_M_spec._M_get_width(__fc) > 0)
> >- return _M_format_with_padding(__rg, __fc);
> >- return _M_format_no_padding(__rg, __fc);
> >+ return __format::__format_padded(
> >+ __fc, _M_spec,
> >+ [this, &__rg](basic_format_context<_Out, _CharT>& __nfc)
> >+ { return _M_format_elems(__rg, __nfc); });
> > }
> >
> >- private:
> >+
> > template<ranges::input_range _Rg, typename _Out>
> > typename basic_format_context<_Out, _CharT>::iterator
> >- _M_format_no_padding(_Rg& __rg,
> >- basic_format_context<_Out, _CharT>& __fc)
> const
> >+ _M_format_elems(_Rg& __rg,
> >+ basic_format_context<_Out, _CharT>& __fc) const
> > {
> > auto __out = __format::__write(__fc.out(), _M_open);
> >
> >@@ -5409,50 +5688,6 @@ namespace __format
> > return __format::__write(__out, _M_close);
> > }
> >
> >- template<ranges::input_range _Rg, typename _Out>
> >- typename basic_format_context<_Out, _CharT>::iterator
> >- _M_format_with_padding(_Rg& __rg,
> >- basic_format_context<_Out, _CharT>& __fc)
> const
> >- {
> >- struct _Restore_out
> >- {
> >- _Restore_out(basic_format_context<_Out, _CharT>& __fc)
> >- : _M_ctx(addressof(__fc)), _M_out(__fc.out())
> >- { }
> >-
> >- void trigger()
> >- {
> >- if (_M_ctx)
> >- _M_ctx->advance_to(_M_out);
> >- _M_ctx = nullptr;
> >- }
> >-
> >- ~_Restore_out()
> >- { trigger(); }
> >-
> >- private:
> >- basic_format_context<_Out, _CharT>* _M_ctx;
> >- __format::_Sink_iter<_CharT> _M_out;
> >- };
> >-
> >- _Restore_out __restore{__fc};
> >- // TODO Consider double sinking, first buffer of width
> >- // size and then original sink, if first buffer is overrun
> >- // we do not need to align
> >- __format::_Str_sink<_CharT> __buf;
> >- __fc.advance_to(__format::_Sink_iter<_CharT>(__buf));
> >- _M_format_no_padding(__rg, __fc);
> >- __restore.trigger();
> >-
> >- _String_view __s(__buf.view());
> >- size_t __width;
> >- if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
> >- __width = __unicode::__field_width(__s);
> >- else
> >- __width = __s.size();
> >- return __format::__write_padded_as_spec(__s, __width, __fc,
> _M_spec);
> >- }
> >-
> > __format::_Spec<_CharT> _M_spec{};
> > _String_view _M_open = _Seps::_S_squares().substr(0, 1);
> > _String_view _M_close = _Seps::_S_squares().substr(1, 1);
> >@@ -5537,7 +5772,7 @@ namespace __format
> > return _M_under._M_format_range(__rg, __fc);
> > else
> > return _M_under.format(__rg, __fc);
> >- }
> >+ }
> >
> > private:
> > using _Formatter_under
> >diff --git a/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
> b/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
> >index 2045b51547a..a4f5d9210dd 100644
> >--- a/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
> >+++ b/libstdc++-v3/testsuite/std/format/ranges/formatter.cc
> >@@ -97,6 +97,7 @@ void
> > test_override()
> > {
> > MyVector<_CharT, Formatter> vc{'a', 'b', 'c', 'd'};
> >+ MyVector<std::pair<int, int>, Formatter> vp{{1, 11}, {2, 21}};
> > std::basic_string<_CharT> res;
> >
> > res = std::format(WIDEN("{:s}"), vc);
> >@@ -106,7 +107,10 @@ test_override()
> > res = std::format(WIDEN("{:+^6s}"), vc);
> > VERIFY( res == WIDEN("+abcd+") );
> >
> >- // TODO test map
> >+ res = std::format(WIDEN("{:m}"), vp);
> >+ VERIFY( res == WIDEN("{1: 11, 2: 21}") );
> >+ res = std::format(WIDEN("{:=^20m}"), vp);
> >+ VERIFY( res == WIDEN("==={1: 11, 2: 21}===") );
> > }
> >
> > template<template<typename, typename> class Formatter>
> >diff --git a/libstdc++-v3/testsuite/std/format/ranges/map.cc
> b/libstdc++-v3/testsuite/std/format/ranges/map.cc
> >new file mode 100644
> >index 00000000000..34c5ed554b8
> >--- /dev/null
> >+++ b/libstdc++-v3/testsuite/std/format/ranges/map.cc
> >@@ -0,0 +1,209 @@
> >+// { dg-do run { target c++23 } }
> >+
> >+#include <flat_map>
> >+#include <format>
> >+#include <list>
> >+#include <map>
> >+#include <span>
> >+#include <testsuite_hooks.h>
> >+#include <testsuite_iterators.h>
> >+#include <vector>
> >+
> >+struct NotFormattable
> >+{
> >+ friend auto operator<=>(NotFormattable, NotFormattable) = default;
> >+};
> >+
> >+static_assert( !std::formattable<std::map<int, NotFormattable>, char> );
> >+static_assert( !std::formattable<std::map<NotFormattable, int>, wchar_t>
> );
> >+
> >+template<typename... Args>
> >+bool
> >+is_format_string_for(const char* str, Args&&... args)
> >+{
> >+ try {
> >+ (void) std::vformat(str, std::make_format_args(args...));
> >+ return true;
> >+ } catch (const std::format_error&) {
> >+ return false;
> >+ }
> >+}
> >+
> >+template<typename... Args>
> >+bool
> >+is_format_string_for(const wchar_t* str, Args&&... args)
> >+{
> >+ try {
> >+ (void) std::vformat(str, std::make_wformat_args(args...));
> >+ return true;
> >+ } catch (const std::format_error&) {
> >+ return false;
> >+ }
> >+}
> >+
> >+template<typename Rg, typename CharT>
> >+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;
> >+ std::basic_format_parse_context<CharT> pc(spec);
> >+ try {
> >+ (void)fmt.parse(pc);
> >+ return true;
> >+ } catch (const std::format_error&) {
> >+ return false;
> >+ }
> >+}
> >+
> >+#define WIDEN_(C, S) ::std::__format::_Widen<C>(S, L##S)
> >+#define WIDEN(S) WIDEN_(_CharT, S)
> >+
> >+void
> >+test_format_string()
> >+{
> >+ // only pair<T, U> amd tuple<T, U> value types are supported
> >+ VERIFY( !is_range_formatter_spec_for("m", std::vector<int>()) );
> >+ VERIFY( !is_format_string_for("{:m}", std::vector<int>()) );
> >+ VERIFY( !is_range_formatter_spec_for("m", std::vector<std::tuple<int,
> int, int>>()) );
> >+ VERIFY( !is_format_string_for("{:m}", std::vector<std::tuple<int, int,
> int>>()) );
> >+
> >+ // invalid format stringss
> >+ VERIFY( !is_range_formatter_spec_for("?m", std::vector<std::pair<int,
> int>>()) );
> >+ VERIFY( !is_format_string_for("{:?m}", std::vector<std::pair<int,
> int>>()) );
> >+ VERIFY( !is_range_formatter_spec_for("m:", std::vector<std::pair<int,
> int>>()) );
> >+ VERIFY( !is_format_string_for("{:m:}", std::vector<std::pair<int,
> int>>()) );
> >+
> >+ // precision is not supported
> >+ VERIFY( !is_range_formatter_spec_for(".10m",
> std::vector<std::pair<int, int>>()) );
> >+ VERIFY( !is_format_string_for("{:.10m}", std::vector<std::pair<int,
> int>>()) );
> >+ VERIFY( !is_format_string_for("{:.{}m}", std::vector<std::pair<int,
> int>>(), 10) );
> >+
> >+ // width needs to be integer type
> >+ VERIFY( !is_format_string_for("{:{}m}", std::vector<std::pair<int,
> int>>(), 1.0f) );
> >+}
> >+
> >+template<typename _CharT, typename Range>
> >+void test_output(bool mapIsDefault)
> >+{
> >+ using Sv = std::basic_string_view<_CharT>;
> >+ using Pt = std::ranges::range_value_t<Range>;
> >+ using Ft = std::remove_cvref_t<std::tuple_element_t<0, Pt>>;
> >+ using St = std::remove_cvref_t<std::tuple_element_t<1, Pt>>;
> >+ auto makeRange = [](std::span<Pt> s) {
> >+ return Range(s.data(), s.data() + s.size());
> >+ };
> >+
> >+ std::basic_string<_CharT> res;
> >+ size_t size = 0;
> >+
> >+ Ft f1[]{1, 2, 3};
> >+ St s1[]{11, 22, 33};
> >+ Pt v1[]{{f1[0], s1[0]}, {f1[1], s1[1]}, {f1[2], s1[2]}};
> >+
> >+ res = std::format(WIDEN("{}"), makeRange(v1));
> >+ if (mapIsDefault)
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33}") );
> >+ else
> >+ VERIFY( res == WIDEN("[(1, 11), (2, 22), (3, 33)]") );
> >+
> >+ res = std::format(WIDEN("{:m}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33}") );
> >+ res = std::format(WIDEN("{:nm}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("1: 11, 2: 22, 3: 33") );
> >+
> >+ res = std::format(WIDEN("{:3m}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33}") );
> >+
> >+ res = std::format(WIDEN("{:25m}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33} ") );
> >+
> >+ res = std::format(WIDEN("{:{}m}"), makeRange(v1), 25);
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33} ") );
> >+
> >+ res = std::format(WIDEN("{1:{0}m}"), 25, makeRange(v1));
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33} ") );
> >+
> >+ res = std::format(WIDEN("{:25nm}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("1: 11, 2: 22, 3: 33 ") );
> >+
> >+ res = std::format(WIDEN("{:*<23m}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("{1: 11, 2: 22, 3: 33}**") );
> >+
> >+ res = std::format(WIDEN("{:->24m}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("---{1: 11, 2: 22, 3: 33}") );
> >+
> >+ res = std::format(WIDEN("{:=^25m}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("=={1: 11, 2: 22, 3: 33}==") );
> >+
> >+ res = std::format(WIDEN("{:=^25nm}"), makeRange(v1));
> >+ VERIFY( res == WIDEN("===1: 11, 2: 22, 3: 33===") );
> >+
> >+ size = std::formatted_size(WIDEN("{:m}"), makeRange(v1));
> >+ VERIFY( size == Sv(WIDEN("{1: 11, 2: 22, 3: 33}")).size() );
> >+
> >+ size = std::formatted_size(WIDEN("{:3m}"), makeRange(v1));
> >+ VERIFY( size == Sv(WIDEN("{1: 11, 2: 22, 3: 33}")).size() );
> >+
> >+ size = std::formatted_size(WIDEN("{:25m}"), makeRange(v1));
> >+ VERIFY( size == 25 );
> >+}
> >+
> >+template<class Range>
> >+void test_output_c(bool mapIsDefault = false)
> >+{
> >+ test_output<char, Range>(mapIsDefault);
> >+ test_output<wchar_t, Range>(mapIsDefault);
> >+}
> >+
> >+template<template<typename> class RangeT>
> >+void test_output_pc()
> >+{
> >+ test_output_c<RangeT<std::pair<int, int>>>();
> >+ test_output_c<RangeT<std::pair<const int, int>>>();
> >+ test_output_c<RangeT<std::tuple<const int&, int&>>>();
> >+}
> >+
> >+void
> >+test_outputs()
> >+{
> >+ using namespace __gnu_test;
> >+ test_output_c<std::map<int, int>>(true);
> >+ test_output_c<std::flat_map<int, int>>(true);
> >+
> >+ test_output_pc<std::vector>();
> >+ test_output_pc<std::list>();
> >+ test_output_pc<std::span>();
> >+
> >+ test_output_pc<test_forward_range>();
> >+ test_output_pc<test_input_range>();
> >+ test_output_pc<test_input_range_nocopy>();
> >+}
> >+
> >+void
> >+test_nested()
> >+{
> >+ std::vector<std::map<int, std::string>> vm{
> >+ {{1, "one"}, {2, "two"}},
> >+ {{1, "jeden"}, {2, "dwa"}},
> >+ };
> >+ std::string res;
> >+
> >+ res = std::format("{}", vm);
> >+ VERIFY( res == R"([{1: "one", 2: "two"}, {1: "jeden", 2: "dwa"}])" );
> >+ res = std::format("{:n:n}", vm);
> >+ VERIFY( res == R"(1: "one", 2: "two", 1: "jeden", 2: "dwa")" );
> >+
> >+ std::map<std::string, std::vector<std::string>> mv{
> >+ {"english", {"zero", "one", "two"}},
> >+ {"polish", {"zero", "jeden", "dwa"}},
> >+ };
> >+ res = std::format("{}", mv);
> >+ VERIFY( res == R"({"english": ["zero", "one", "two"], "polish":
> ["zero", "jeden", "dwa"]})" );
> >+}
> >+
> >+int main()
> >+{
> >+ test_format_string();
> >+ test_outputs();
> >+ test_nested();
> >+}
> >diff --git a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> >index 06574379ed5..61fc68ea252 100644
> >--- a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> >+++ b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> >@@ -1,7 +1,9 @@
> > // { dg-do run { target c++23 } }
> >
> >+#include <array>
> > #include <format>
> > #include <list>
> >+#include <ranges>
> > #include <span>
> > #include <testsuite_hooks.h>
> > #include <testsuite_iterators.h>
> >@@ -73,19 +75,23 @@ test_format_string()
> > #define WIDEN_(C, S) ::std::__format::_Widen<C>(S, L##S)
> > #define WIDEN(S) WIDEN_(_CharT, S)
> >
> >-template<typename _CharT, typename Range>
> >+template<typename _CharT, typename Range, typename Storage>
> > void test_output()
> > {
> > using Sv = std::basic_string_view<_CharT>;
> > using T = std::ranges::range_value_t<Range>;
> >- auto makeRange = [](std::span<T> s) {
> >- return Range(s.data(), s.data() + s.size());
> >+ auto makeRange = [](Storage& s) -> Range {
> >+ if constexpr (std::is_same_v<std::remove_cvref_t<Range>, Storage>)
> >+ return s;
> >+ else
> >+ return Range(std::ranges::data(s),
> >+ std::ranges::data(s) + std::ranges::size(s));
> > };
> >
> > std::basic_string<_CharT> res;
> > size_t size = 0;
> >
> >- T v1[]{1, 2, 3};
> >+ Storage v1{1, 2, 3};
> > res = std::format(WIDEN("{}"), makeRange(v1));
> > VERIFY( res == WIDEN("[1, 2, 3]") );
> > res = std::format(WIDEN("{:}"), makeRange(v1));
> >@@ -143,27 +149,37 @@ void test_output()
> > VERIFY( size == 25 );
> > }
> >
> >-template<typename Range>
> >-void test_output_c()
> >+template<typename Cont>
> >+void test_output_cont()
> > {
> >- test_output<char, Range>();
> >- test_output<wchar_t, Range>();
> >+ test_output<char, Cont&, Cont>();
> >+ test_output<wchar_t, Cont const&, Cont>();
> >+}
> >+
> >+template<typename View>
> >+void test_output_view()
> >+{
> >+ test_output<char, View, int[3]>();
> >+ test_output<wchar_t, View, int[3]>();
> > }
> >
> > void
> > test_outputs()
> > {
> > using namespace __gnu_test;
> >- test_output_c<std::vector<int>>();
> >- test_output_c<std::list<int>>();
> >- test_output_c<std::span<int>>();
> >-
> >- test_output_c<test_forward_range<int>>();
> >- test_output_c<test_input_range<int>>();
> >- test_output_c<test_range_nocopy<int, input_iterator_wrapper_nocopy>>();
> >-
> >- test_output_c<std::span<const int>>();
> >- test_output_c<test_forward_range<const int>>();
> >+ test_output_cont<std::vector<int>>();
> >+ test_output_cont<std::list<int>>();
> >+ test_output_cont<std::array<int, 3>>();
> >+
> >+ test_output_view<std::span<int>>();
> >+ test_output_view<std::ranges::subrange<int*>>();
> >+ test_output_view<test_forward_range<int>>();
> >+ test_output_view<test_input_range<int>>();
> >+ test_output_view<test_input_range_nocopy<int>>();
> >+
> >+ test_output_view<std::span<const int>>();
> >+ test_output_view<std::ranges::subrange<const int*>>();
> >+ test_output_view<test_forward_range<const int>>();
> > }
> >
> > void
> >diff --git a/libstdc++-v3/testsuite/std/format/tuple.cc
> b/libstdc++-v3/testsuite/std/format/tuple.cc
> >new file mode 100644
> >index 00000000000..62f9d293aab
> >--- /dev/null
> >+++ b/libstdc++-v3/testsuite/std/format/tuple.cc
> >@@ -0,0 +1,259 @@
> >+// { dg-do run { target c++23 } }
> >+
> >+#include <format>
> >+#include <string>
> >+#include <testsuite_hooks.h>
> >+#include <tuple>
> >+#include <utility>
> >+
> >+struct NotFormattable
> >+{};
> >+
> >+static_assert( !std::formattable<std::pair<int, NotFormattable>, char> );
> >+static_assert( !std::formattable<std::tuple<int, NotFormattable, int>,
> wchar_t> );
> >+
> >+template<typename... Args>
> >+bool
> >+is_format_string_for(const char* str, Args&&... args)
> >+{
> >+ try {
> >+ (void) std::vformat(str, std::make_format_args(args...));
> >+ return true;
> >+ } catch (const std::format_error&) {
> >+ return false;
> >+ }
> >+}
> >+
> >+template<typename... Args>
> >+bool
> >+is_format_string_for(const wchar_t* str, Args&&... args)
> >+{
> >+ try {
> >+ (void) std::vformat(str, std::make_wformat_args(args...));
> >+ return true;
> >+ } catch (const std::format_error&) {
> >+ return false;
> >+ }
> >+}
> >+
> >+#define WIDEN_(C, S) ::std::__format::_Widen<C>(S, L##S)
> >+#define WIDEN(S) WIDEN_(_CharT, S)
> >+
> >+void
> >+test_format_string()
> >+{
> >+ // invalid format stringss
> >+ VERIFY( !is_format_string_for("{:p}", std::tuple<>()) );
> >+ VERIFY( !is_format_string_for("{:nm}", std::tuple<>()) );
> >+
> >+ // 'm' is only valid for 2 elemenst
> >+ VERIFY( !is_format_string_for("{:m}", std::tuple<>()) );
> >+ VERIFY( !is_format_string_for("{:m}", std::tuple<int, int, int>()) );
> >+
> >+ // element specifier is not supported
> >+ VERIFY( !is_format_string_for("{::}", std::tuple<>()) );
> >+
> >+ // precision is not supported
> >+ VERIFY( !is_format_string_for("{:.10}", std::tuple<>()) );
> >+
> >+ // width needs to be integer type
> >+ VERIFY( !is_format_string_for("{:{}}", std::tuple<>(), 1.0f) );
> >+}
> >+
> >+template<typename _CharT>
> >+void test_multi()
> >+{
> >+ using Sv = std::basic_string_view<_CharT>;
> >+ using Str = std::basic_string<_CharT>;
> >+
> >+ std::basic_string<_CharT> res;
> >+ std::size_t size = 0;
> >+ std::tuple<int, Str, float> t1(1, WIDEN("test"), 2.1);
> >+
> >+ res = std::format(WIDEN("{}"), t1);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1))") );
> >+ res = std::format(WIDEN("{:}"), t1);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1))") );
> >+ res = std::format(WIDEN("{:n}"), t1);
> >+ VERIFY( res == WIDEN(R"(1, "test", 2.1)") );
> >+
> >+ res = std::format(WIDEN("{:3}"), t1);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1))") );
> >+
> >+ res = std::format(WIDEN("{:20}"), t1);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1) )") );
> >+
> >+ res = std::format(WIDEN("{:{}}"), t1, 20);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1) )") );
> >+
> >+ res = std::format(WIDEN("{1:{0}}"), 20, t1);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1) )") );
> >+
> >+ res = std::format(WIDEN("{:^>17}"), t1);
> >+ VERIFY( res == WIDEN(R"(^(1, "test", 2.1))") );
> >+
> >+ res = std::format(WIDEN("{:$<18}"), t1);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1)$$)") );
> >+
> >+ res = std::format(WIDEN("{:+^19}"), t1);
> >+ VERIFY( res == WIDEN(R"(+(1, "test", 2.1)++)") );
> >+
> >+ res = std::format(WIDEN("{:|^19n}"), t1);
> >+ VERIFY( res == WIDEN(R"(||1, "test", 2.1|||)") );
> >+
> >+ size = std::formatted_size(WIDEN("{}"), t1);
> >+ VERIFY( size == Sv(WIDEN(R"((1, "test", 2.1))")).size() );
> >+
> >+ size = std::formatted_size(WIDEN("{:3}"), t1);
> >+ VERIFY( size == Sv(WIDEN(R"((1, "test", 2.1))")).size() );
> >+
> >+ size = std::formatted_size(WIDEN("{:20}"), t1);
> >+ VERIFY( size == 20 );
> >+
> >+ std::tuple<int&, Str&, float&> t2 = t1;
> >+ res = std::format(WIDEN("{}"), t2);
> >+ VERIFY( res == WIDEN(R"((1, "test", 2.1))") );
> >+
> >+ std::tuple<int, int, int, int> t3(1, 2, 3, 4);
> >+ res = std::format(WIDEN("{}"), t3);
> >+ VERIFY( res == WIDEN(R"((1, 2, 3, 4))") );
> >+
> >+}
> >+
> >+template<typename _CharT, typename Tuple>
> >+void test_empty()
> >+{
> >+ std::basic_string<_CharT> res;
> >+
> >+ Tuple e1;
> >+ res = std::format(WIDEN("{}"), e1);
> >+ VERIFY( res == WIDEN(R"(())") );
> >+
> >+ res = std::format(WIDEN("{:}"), e1);
> >+ VERIFY( res == WIDEN(R"(())") );
> >+
> >+ res = std::format(WIDEN("{:n}"), e1);
> >+ VERIFY( res == WIDEN(R"()") );
> >+
> >+ res = std::format(WIDEN("{:^>6}"), e1);
> >+ VERIFY( res == WIDEN(R"(^^^^())") );
> >+}
> >+
> >+template<typename _CharT, typename Pair>
> >+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>>;
> >+
> >+ std::basic_string<_CharT> res;
> >+
> >+ Ft f1 = 1;
> >+ St s1 = WIDEN("abc");
> >+ Pair p1(f1, s1);
> >+
> >+ res = std::format(WIDEN("{}"), p1);
> >+ VERIFY( res == WIDEN(R"((1, "abc"))") );
> >+
> >+ res = std::format(WIDEN("{:}"), p1);
> >+ VERIFY( res == WIDEN(R"((1, "abc"))") );
> >+
> >+ res = std::format(WIDEN("{:m}"), p1);
> >+ VERIFY( res == WIDEN(R"(1: "abc")") );
> >+
> >+ res = std::format(WIDEN("{:|^12m}"), p1);
> >+ VERIFY( res == WIDEN(R"(||1: "abc"||)") );
> >+}
> >+
> >+template<typename CharT, template<typename, typename> class PairT>
> >+void test_pair_e()
> >+{
> >+ test_pair<CharT, PairT<int, std::basic_string<CharT>>>();
> >+ test_pair<CharT, PairT<int, const CharT*>>();
> >+ test_pair<CharT, PairT<const int, std::basic_string<CharT>>>();
> >+ test_pair<CharT, PairT<int&, std::basic_string<CharT>&>>();
> >+ test_pair<CharT, PairT<const int&, const std::basic_string<CharT>&>>();
> >+}
> >+
> >+template<typename Pair>
> >+struct MyPair : Pair
> >+{
> >+ using Pair::Pair;
> >+};
> >+
> >+template<typename Pair, typename CharT>
> >+struct std::formatter<MyPair<Pair>, CharT>
> >+{
> >+ constexpr formatter() noexcept
> >+ {
> >+ using _CharT = CharT;
> >+ _formatter.set_brackets(WIDEN("<"), WIDEN(">"));
> >+ _formatter.set_separator(WIDEN("; "));
> >+ }
> >+
> >+ constexpr std::basic_format_parse_context<CharT>::iterator
> >+ parse(std::basic_format_parse_context<CharT>& pc)
> >+ { return _formatter.parse(pc); }
> >+
> >+ template<typename Out>
> >+ 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); }
> >+
> >+private:
> >+ std::formatter<Pair, CharT> _formatter;
> >+};
> >+
> >+template<typename _CharT, template<typename, typename> class PairT>
> >+void test_custom()
> >+{
> >+ std::basic_string<_CharT> res;
> >+ MyPair<PairT<int, const _CharT*>> c1(1, WIDEN("abc"));
> >+
> >+ res = std::format(WIDEN("{}"), c1);
> >+ VERIFY( res == WIDEN(R"(<1; "abc">)") );
> >+
> >+ res = std::format(WIDEN("{:}"), c1);
> >+ VERIFY( res == WIDEN(R"(<1; "abc">)") );
> >+
> >+ res = std::format(WIDEN("{:n}"), c1);
> >+ VERIFY( res == WIDEN(R"(1; "abc")") );
> >+
> >+ res = std::format(WIDEN("{:m}"), c1);
> >+ VERIFY( res == WIDEN(R"(1: "abc")") );
> >+
> >+ res = std::format(WIDEN("{:|^14}"), c1);
> >+ VERIFY( res == WIDEN(R"(||<1; "abc">||)") );
> >+}
> >+
> >+template<typename CharT>
> >+void test_outputs()
> >+{
> >+ test_multi<CharT>();
> >+ test_empty<CharT, std::tuple<>>();
> >+ test_pair_e<CharT, std::pair>();
> >+ test_pair_e<CharT, std::tuple>();
> >+ test_custom<CharT, std::pair>();
> >+ test_custom<CharT, std::tuple>();
> >+}
> >+
> >+void test_nested()
> >+{
> >+ std::string res;
> >+ std::tuple<std::tuple<>, std::pair<int, std::string>> tt{{}, {1,
> "abc"}};
> >+
> >+ res = std::format("{}", tt);
> >+ VERIFY( res == R"(((), (1, "abc")))" );
> >+ res = std::format("{:n}", tt);
> >+ VERIFY( res == R"((), (1, "abc"))" );
> >+ res = std::format("{:m}", tt);
> >+ VERIFY( res == R"((): (1, "abc"))" );
> >+}
> >+
> >+int main()
> >+{
> >+ test_format_string();
> >+ test_outputs<char>();
> >+ test_outputs<wchar_t>();
> >+ test_nested();
> >+}
> >diff --git a/libstdc++-v3/testsuite/util/testsuite_iterators.h
> b/libstdc++-v3/testsuite/util/testsuite_iterators.h
> >index 20539ecaca6..74a87395cd7 100644
> >--- a/libstdc++-v3/testsuite/util/testsuite_iterators.h
> >+++ b/libstdc++-v3/testsuite/util/testsuite_iterators.h
> >@@ -891,6 +891,9 @@ namespace __gnu_test
> > template<typename T>
> > using test_input_range
> > = test_range<T, input_iterator_wrapper>;
> >+ template<typename T>
> >+ using test_input_range_nocopy
> >+ = test_range_nocopy<T, input_iterator_wrapper_nocopy>;
> > template<typename T>
> > using test_output_range
> > = test_range<T, output_iterator_wrapper>;
> >--
> >2.49.0
> >
> >
>
>
