https://gcc.gnu.org/g:70bd97e89ddf8fcb8c14e84a8fd580404536eeb1
commit r16-2107-g70bd97e89ddf8fcb8c14e84a8fd580404536eeb1 Author: Tomasz KamiĆski <tkami...@redhat.com> Date: Tue Jul 8 10:04:41 2025 +0200 libstdc++: Do not expose set_brackets/set_separator for formatter with format_kind other than sequence [PR119861] The standard defines separate specializations of range-default-formatter, out of which only one for range_format::sequence provide the set_brackets and set_separator methods. We implemented it as one specialization and exposed this method for range_format other than string or debug_string, i.e. when range_formatter was used as underlying formatter. PR libstdc++/119861 libstdc++-v3/ChangeLog: * include/std/format (formatter<_Rg, _CharT>::set_separator) (formatter<_Rg, _CharT>::set_brackets): Constrain with (format_kind<_Rg> == range_format::sequence). * testsuite/std/format/ranges/pr119861_neg.cc: New test. Diff: --- libstdc++-v3/include/std/format | 4 +- .../testsuite/std/format/ranges/pr119861_neg.cc | 52 ++++++++++++++++++++++ 2 files changed, 54 insertions(+), 2 deletions(-) diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 5749aa1995a9..d584b81c78a1 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -6030,13 +6030,13 @@ namespace __format constexpr void set_separator(basic_string_view<_CharT> __sep) noexcept - requires (!_S_range_format_is_string) + requires (format_kind<_Rg> == range_format::sequence) { _M_under.set_separator(__sep); } constexpr void set_brackets(basic_string_view<_CharT> __open, basic_string_view<_CharT> __close) noexcept - requires (!_S_range_format_is_string) + requires (format_kind<_Rg> == range_format::sequence) { _M_under.set_brackets(__open, __close); } // We deviate from standard, that declares this as template accepting diff --git a/libstdc++-v3/testsuite/std/format/ranges/pr119861_neg.cc b/libstdc++-v3/testsuite/std/format/ranges/pr119861_neg.cc new file mode 100644 index 000000000000..9a6ed16393ee --- /dev/null +++ b/libstdc++-v3/testsuite/std/format/ranges/pr119861_neg.cc @@ -0,0 +1,52 @@ +// { dg-do compile { target c++23 } } + +#include <format> +#include <vector> + +// only format_kind::sequence provides set_brackets and set_separator methods + +template<std::range_format fk, typename T> +struct MyCont : std::vector<T> +{ + using std::vector<T>::vector; +}; + +template<std::range_format fk, typename T> +constexpr std::range_format std::format_kind<MyCont<fk, T>> = fk; + +void test_sequence() +{ + std::formatter<MyCont<std::range_format::sequence, int>, char> fmtter; + fmtter.set_brackets("{", "}"); + fmtter.set_separator(","); +} + +void test_map() +{ + std::formatter<MyCont<std::range_format::map, std::pair<int, int>>, char> fmtter; + fmtter.set_brackets("{", "}"); // { dg-error "here" } + fmtter.set_separator(","); // { dg-error "here" } +} + +void test_set() +{ + std::formatter<MyCont<std::range_format::set, int>, char> fmtter; + fmtter.set_brackets("{", "}"); // { dg-error "here" } + fmtter.set_separator(","); // { dg-error "here" } +} + +void test_string() +{ + std::formatter<MyCont<std::range_format::string, char>, char> fmtter; + fmtter.set_brackets("{", "}"); // { dg-error "here" } + fmtter.set_separator(","); // { dg-error "here" } +} + +void test_debug_string() +{ + std::formatter<MyCont<std::range_format::debug_string, char>, char> fmtter; + fmtter.set_brackets("{", "}"); // { dg-error "here" } + fmtter.set_separator(","); // { dg-error "here" } +} + +// { dg-error "no matching function for call to 'std::formatter<" "" { target *-*-* } 0 }