Looks good to me, even with core modules. =)

Yes, Tie::Handle and Tie::StdHandle aren't too bad, they're just not necessarily consistent across Perl versions. For example, Tie::StdHandle::BINMODE didn't handle a "layer" argument until I patched it (this fix wasn't included until v5.32.0). Also, its sub WRITE still doesn't return the length of the data written, like syswrite normally would. Tie::Handle::Base works the same all the way down to Perl 5.8.1 (of course I have lots of tests :-) ).