Tested x86_64-linux. Richi confirmed this fixes rx-elf bootstrap. Pushed to trunk.
-- >8 -- If the faster std::from_chars is not supported for floating-point types then just extract the value from the stream using operator>>. This fixes a build error for targets where __cpp_lib_to_chars is not defined. libstdc++-v3/ChangeLog: PR libstdc++/114633 * include/bits/chrono_io.h (_Parser::operator()) <'S'>: Use stream extraction if std::from_chars is not available. --- libstdc++-v3/include/bits/chrono_io.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h index b9eb3d2be53..3b34992b42a 100644 --- a/libstdc++-v3/include/bits/chrono_io.h +++ b/libstdc++-v3/include/bits/chrono_io.h @@ -3685,6 +3685,7 @@ namespace __detail if (!__is_failed(__err)) [[likely]] { long double __val{}; +#if __cpp_lib_to_chars string __str = std::move(__buf).str(); auto __first = __str.data(); auto __last = __first + __str.size(); @@ -3694,6 +3695,9 @@ namespace __detail if ((bool)ec || ptr != __last) [[unlikely]] __err |= ios_base::failbit; else +#else + if (__buf >> __val) +#endif { duration<long double> __fs(__val); if constexpr (__is_floating) -- 2.44.0