Niels Lohmann 4cad4e08a4 Replace snprintf with a branch-free writer for \uXXXX escapes ...

dump_escaped called std::snprintf(..., "\u%04x", ...) once per escaped
code point in the string serialization hot path. snprintf re-parses
the format string and pulls in locale/printf machinery on every call,
which is far heavier than the fixed 6-/12-byte output warrants. This
is hot for any string containing control characters, and for all
non-ASCII text when ensure_ascii is set.

Replace it with write_u_escape, a small helper that writes the escape
directly into string_buffer via a nibble-to-hex lookup table, mirroring
the existing hand-rolled dump_integer fast path in the same file.

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

2026-07-06 08:33:47 +02:00

..

json_fwd.hpp

🦉 adjust year (#5044)

2026-01-01 20:00:39 +01:00

json.hpp

Replace snprintf with a branch-free writer for \uXXXX escapes

2026-07-06 08:33:47 +02:00