http://www.perlmonks.org?node_id=315715


in reply to package Foo; isa Bar; why not?

Any chance of a require? I do like it over use base even if the only thing changing between the two is that you can say isa Bar instead of use base "Bar". There is one slight catch, though:

#!/usr/bin/perl -wl our @ISA; use isa; isa Foo,Bar; # drops Bar and also spits out warning... # works same if you quote Bar, dies if Foo # is quoted or we're under strict print "@ISA"; @ISA = (); Foo->isa("Bar"); # this works but the syntax is...funky print "@ISA"; @ISA = (); UNIVERSAL::isa(qw(Foo Bar)); # kinda long, eh? print "@ISA"; @ISA = (); main->isa(qw(Foo Bar)); # makes sense... pushes itself onto # @ISA, though __END__ Useless use of a constant in void context at isa.pl line 5. Foo Foo Bar Foo Bar main Foo Bar

It doesn't do the right thing if you'd like to declare it for more than one package at a time. With base you can do as many as you want. The only ways I can think of fixing it is to actually export a version to the package that's using isa's functionality. I dunno. Works great for one package but otherwise doesn't seem to be as clean of a solution as it could be.