Em Sex, 2009-02-20 às 11:19 +1100, Timothy S. Nelson escreveu:
> if(! defined($footree.root)) { warn "Unrooted tree"; }
There are some other very interesting possibilities:
unless ($footree.can(root)) { warn "Unrooted tree"; }
or even better
unless ($footree ~~ RootedTree) { warn "Unrooted tree"; }
or yet even better
my RootedTree $footree = something()
and it fails automatically...
*That's* what Roles are for...
daniel
