Are there any services similar to codepad that will allow you to test Perl constructs on old versions of perl?
Ideally, a system where you could enter an expression and it will tell you the oldest version of perl that it will work with.
Of course it’s possible to use CPANTS for this, but that seems like an abuse of the service (if only for making the BackPan bigger). And it could take several days/weeks to get decent test coverage on old versions.
You might find Perl::MinimumVersion helpful. Use the provided perlver utility to scan your code.