[PATCH 5/6] libstdc++: Use fast_float in std::from_chars for binary32/64

[Jonathan Wakely]

On Sun, 16 Jan 2022 at 18:09, Patrick Palka via Libstdc++ <
libstdc++@gcc.gnu.org> wrote:

> This makes our std::from_chars implementation use fast_float for parsing
> chars_format::scientific/fixed/general parsing into binary32/64 values.
> For other floating-point formats we still use the fallback implementation
> that goes through the strtod family of functions.
>
> libstdc++-v3/ChangeLog:
>
>         * src/c++17/floating_from_chars.cc: (USE_LIB_FAST_FLOAT):
>         Conditionally define, and use it to conditionally include
>         fast_float.
>         (from_chars): Use fast_float for float and double when
>         USE_LIB_FAST_FLOAT.
>
>
OK for trunk.