gtk-check-version (major minor micro)

major -- the required major version
minor -- the required minor version
micro -- the required micro version

Nil if the GTK library is compatible with the given version, or a string describing the version mismatch.

Checks that the GTK library in use is compatible with the given version.

Compatibility is defined by two things: first the version of the running library is newer than the version major.minor.micro. Second the running library must be binary compatible with the version major.minor.micro (same major version).