the required major version
the required minor version
the required micro version
%NULL if the GLib library is compatible with the given version, or a string describing the version mismatch. The returned string is owned by GLib and must not be modified or freed.
2.6
Checks that the GLib library in use is compatible with the given version. Generally you would pass in the constants #GLIB_MAJOR_VERSION, #GLIB_MINOR_VERSION, #GLIB_MICRO_VERSION as the three arguments to this function; that produces a check that the library in use is compatible with the version of GLib the application or module was compiled against.
Compatibility is defined by two things: first the version of the running library is newer than the version @required_major.required_minor.@required_micro. Second the running library must be binary compatible with the version @required_major.required_minor.@required_micro (same major version.)