PCRE2 is a re-working of the original PCRE (Perl-compatible regular
expression) library to provide an entirely new API.

PCRE2 is written in C, and it has its own API. There are three sets of
functions, one for the 8-bit library, which processes strings of bytes, one
for the 16-bit library, which processes strings of 16-bit values, and one for
the 32-bit library, which processes strings of 32-bit values. There are no C++
wrappers.

The distribution does contain a set of C wrapper functions for the 8-bit
library that are based on the POSIX regular expression API (see the pcre2posix
man page). These can be found in a library called libpcre2posix. Note that
this just provides a POSIX calling interface to PCRE2; the regular expressions
themselves still follow Perl syntax and semantics. The POSIX API is
restricted, and does not give full access to all of PCRE2's facilities.