The latest release of Devel::TypeCheck adds typing of functions (without polymorphism) as well as numerous bug fixes:
The uploaded file Devel-TypeCheck-1.2.tar.gz has entered CPAN as file: $CPAN/authors/id/B/BA/BARGLE/Devel-TypeCheck-1.2.tar.gz size: 37304 bytes md5: 04369069c2a307c85bbe54ee5a267c9b -- Gary