Niels Lohmann 42e3489abd Prefer strtod_l over libc++'s std::from_chars ...

libc++'s std::from_chars for float and double is 1.3x to 2.8x slower
per number than Apple's strtod_l, and it was tried before Clinger's
fast path. With Apple clang in C++17 mode, parsing random doubles took
1.75x as long as on develop, short numbers such as 123.45 1.3x, and
mesh.json 1.2x.

Use libc++'s std::from_chars only where the C library has no strtod_l.
On Apple platforms, floats are now converted by Clinger's fast path and
strtod_l, which is 0.90x to 1.01x the time of develop.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

2026-09-30 10:12:50 +02:00

..

json_fwd.hpp

Make JSON_STRICT_NUL_HANDLING part of the ABI tag (#5560)

2026-09-25 21:54:11 +02:00

json.hpp

Prefer strtod_l over libc++'s std::from_chars

2026-09-30 10:12:50 +02:00