https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119246
Bug ID: 119246
Summary: Result basic_format_arg::check_dynamic_spec is
incorrect for extended floating point types
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: tkaminsk at gcc dot gnu.org
Target Milestone: ---
Currently for parse_con `ctx.check_dynamic_spec<float>(n)` returns true,
if the argument at the position n have std::bfloat16_t, std::float16_t
(_Float16), std::float32_t (_Float32).
Similary `ctx.check_dynamic_spec<double>(n)` returns true for the
std::float64_t (_Float64).
Code example (https://godbolt.org/z/Enc5WzaKn):
```
#include <format>
template<unsigned pos, class Type>
struct Tester {};
template<unsigned pos, class Type>
struct std::formatter<Tester<pos, Type>, char> {
constexpr format_parse_context::iterator parse(format_parse_context& ctx)
const {
ctx.check_dynamic_spec<Type>(pos);
return ctx.begin();
}
template<typename Out>
Out format(Tester<pos, Type>, basic_format_context<Out, char>& ctx) const {
return ctx.out();
}
};
static_assert(std::formattable<Tester<1, float>, char>);
int main() {
(void)std::format("{}{}", Tester<1, float>{}, _Float16{});
(void)std::format("{}{}", Tester<1, double>{}, _Float64{});
//std::format("{}{}", Tester<1, int>{}, _Float16{});
}
```
