Array elements are addressed by a plain index of up to 9 digits in nearly
all flattened documents. Parse it straight from the key instead of copying
the token into a string and converting that. A new container whose first
child has the token 0 is an array by definition, so the hash set of array
prefixes is only consulted for other first children.
unflatten() (instructions on macOS, Linux Ir GCC 13 / Clang 18): canada 188.4M ->
161.1M, 151.3M -> 128.1M / 162.3M -> 138.0M; citm_catalog 45.0M -> 43.3M, 40.3M
-> 38.9M / 41.1M -> 39.6M; twitter unchanged. Output and exceptions are
identical to develop over the differential check.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
Niels Lohmann
f2c0e8b6f9