The nng_version() function returns a human readable version number
for the nng library.
This is intended for output in programs, and so forth.
Additionally, compile time version information is available via some predefined macros:
NNG_MAJOR_VERSION-
Major version number.
NNG_MINOR_VERSION-
Minor version number.
NNG_PATCH_VERSION-
Patch version number.
The nng library is developed and released using Semantic Versioning 2.0, and the version numbers reported refer to both the API and the library itself. (The ABI — application binary interface — between the library and the application is controlled in a similar, but different manner depending upon the link options and how the library is built.)