Moose is Not a source filter.
Although Moose does list Filter::Simple as a prerequisite, Moose itself does not use it. It's only there to support the commandline oose.pm module, which is a quick little package to make it easier to do Moosey things from the commandline. For example:
perl -Moose=Foo -e 'has bar => ( is=>q[ro], default => q[baz] ); print Foo->new->bar' # prints baz
perl 'Package Foo; use Moose; has bar => ( is=>q[ro], default => q[baz] ); print Foo->new->bar' # prints baz
So, please, don't say Moose is a source filter. It's all Perl goodness from top to bottom!
Thank you for your attention.