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.
The library is available as 32-bit and 64-bit: