- overwriting any other kind of magic. It returns true on success or when
- $wiz magic is already present, and false on error.
-
- # Casts $wiz to $x
+ overwriting any other kind of magic. You can also supply the numeric
+ signature $sig instead of $wiz. It returns true on success or when $wiz
+ magic is already present, 0 on error, and "undef" when no magic
+ corresponds to the given signature (in case $sig was supplied). All
+ extra arguments specified after $wiz are passed to the private data
+ constructor.
+
+ # Casts $wiz onto $x. If $wiz isn't a signature, undef can't be returned.