diff --git a/libstdc++-v3/include/std/format b/libstdc++-v3/include/std/format index 7c52cce5dbb..58cd310db4d 100644 --- a/libstdc++-v3/include/std/format +++ b/libstdc++-v3/include/std/format @@ -3220,10 +3220,14 @@ namespace __format return type_identity<__format::__float128_t>(); # endif #endif - else if constexpr (__is_specialization_of<_Td, basic_string_view>) - return type_identity>(); - else if constexpr (__is_specialization_of<_Td, basic_string>) - return type_identity>(); + else if constexpr (__is_specialization_of<_Td, basic_string_view> + || __is_specialization_of<_Td, basic_string>) + { + if constexpr (is_same_v) + return type_identity>(); + else + return type_identity(); + } else if constexpr (is_same_v, const _CharT*>) return type_identity(); else if constexpr (is_same_v, _CharT*>) diff --git a/libstdc++-v3/testsuite/std/format/arguments/112607.cc b/libstdc++-v3/testsuite/std/format/arguments/112607.cc new file mode 100644 index 00000000000..19eec765ea5 --- /dev/null +++ b/libstdc++-v3/testsuite/std/format/arguments/112607.cc @@ -0,0 +1,30 @@ +// { dg-do compile { target c++20 } } + +// PR libstdc++/112607 +// _Normalize does not consider char_type for the basic_string_view case + +#include + +template +struct Alloc +{ + using value_type = T; + Alloc() = default; + template + Alloc(const Alloc&) { } + T* allocate(std::size_t); + void deallocate(T*, std::size_t); + bool operator==(const Alloc&) const; +}; + +template +using String = std::basic_string, Alloc>; + +template<> +struct std::formatter> : std::formatter { + auto format(const String&, auto& ctx) const { + return std::formatter::format(" ", ctx); + } +}; + +std::string str = std::format("{}", String{});