This function builds a set of character tables for character values less than
256. These can be passed to pcre2_compile() in a compile context in order
to override the internal, built-in tables (which were either defaulted or made
by pcre2_maketables() when PCRE2 was compiled). See the
page. You might want to do this if you are using a non-standard locale.
If the argument is NULL, malloc() is used to get memory for the tables.
Otherwise it must point to a general context, which can supply pointers to a
custom memory manager. The function yields a pointer to the tables.
There is a complete description of the PCRE2 native API in the
page and a description of the POSIX API in the