use strict; use warnings; use Test::More tests => 9; { package root; sub base { "do" } package foo; @foo::ISA = 'root'; sub new { bless {@_[1 .. $#_]}, $_[0] } sub hey { 'yo' } } sub add_method_to_class { my($cls, $name, $meth) = @_; no strict 'refs'; *{"$cls\::$name"} = $meth; } sub add_method_to_obj { my($obj, $name, $meth) = @_; my $class = ref $obj; (my $objcls = "$obj") =~ s/[^A-Z0-9]//ig; { no strict 'refs'; *{"$objcls\::ISA"} = [ @{"$class\::ISA"}, $class ]; } $_[0] = bless { %$obj }, $objcls; add_method_to_class($objcls, $name, $meth); } can_ok foo => 'hey'; can_ok foo => 'base'; eval { foo->new->yay } or pass "foo can't yay"; add_method_to_class('foo', yay => sub { "yay!" }); can_ok foo => 'yay'; my $o = foo->new; eval { $o->woo } or pass "\$o can't woo"; add_method_to_obj($o, woo => sub { "woo!" }); can_ok $o => 'woo'; eval { foo->new->woo } or pass "foo can't woo"; can_ok $o => 'base'; can_ok $o => 'hey';