Comment: I regularly take advantage of the runtime has(). (Score 1) on 2010.08.03 10:37
Theoretically, Moose could use Hooks::EndOfScope like namespace::clean, but having a dividing line in the middle of a module can be useful.
If someone would get his act together, we'd have a non-dev release of Perl::Critic::Moose out that can check a lot of this stuff for you, e.g. that you don't use with() multiple times.
