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