When using B this way, I like to guard against bad input. For instance, if you pass an array ref, with the above you'll croak with: Can't locate object method "STASH" via package "B::AV". Rather than check with ref or reftype or can or check what type of object svref_2object returns, I just wrap it in an eval and return undef if something goes wrong:

use B;
sub cv2name {
   eval {
      my $obj = B::svref_2object( shift() );
      $obj->STASH->NAME . "::" . $obj->GV->NAME;
   } || undef;
}
[download]