This makes fast_float handle the situation where std::from_chars is specified to return result_out_of_range, i.e. when the parsed value is outside the representable range of the floating-point type.
libstdc++-v3/ChangeLog: * src/c++17/fast_float/LOCAL_PATCHES: Update. * src/c++17/fast_float/parse_number.h (from_chars_advanced): In case of over/underflow, return errc::result_out_of_range and don't modify 'value'. --- libstdc++-v3/src/c++17/fast_float/LOCAL_PATCHES | 1 + libstdc++-v3/src/c++17/fast_float/parse_number.h | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/libstdc++-v3/src/c++17/fast_float/LOCAL_PATCHES b/libstdc++-v3/src/c++17/fast_float/LOCAL_PATCHES index e9d7bba6195..1f90f9d1d85 100644 --- a/libstdc++-v3/src/c++17/fast_float/LOCAL_PATCHES +++ b/libstdc++-v3/src/c++17/fast_float/LOCAL_PATCHES @@ -1 +1,2 @@ r12-???? +r12-???? diff --git a/libstdc++-v3/src/c++17/fast_float/parse_number.h b/libstdc++-v3/src/c++17/fast_float/parse_number.h index 86dea2287b4..57b3585c2fe 100644 --- a/libstdc++-v3/src/c++17/fast_float/parse_number.h +++ b/libstdc++-v3/src/c++17/fast_float/parse_number.h @@ -99,6 +99,16 @@ from_chars_result from_chars_advanced(const char *first, const char *last, // If we called compute_float<binary_format<T>>(pns.exponent, pns.mantissa) and we have an invalid power (am.power2 < 0), // then we need to go the long way around again. This is very uncommon. if(am.power2 < 0) { am = digit_comp<T>(pns, am); } + + if((pns.mantissa != 0 && am.mantissa == 0 && am.power2 == 0) || am.power2 == binary_format<T>::infinite_power()) { + // In case of over/underflow, return result_out_of_range and don't modify value, + // as per [charconv.from.chars]/1. + // + // If LWG 3081 gets adopted, then we'll need to call to_float in this case too. + answer.ec = std::errc::result_out_of_range; + return answer; + } + to_float(pns.negative, am, value); return answer; } -- 2.34.0