Test::Identity provides a single testing function, identical. It asserts that a
given reference is as expected; that is, it either refers to the same object or
is undef. It is similar to Test::More::is except that it uses refaddr, ensuring
that it behaves correctly even if the references under test are objects that
overload stringification or numification.

It also provides better diagnostics if the test fails.

WWW: http://search.cpan.org/dist/Test-Identity/