If you want to override a predefined function, such as open(),
then you'll have to import the new definition from a different
-module. See L<perlsub/"Overriding Builtin Functions">. There's
+module. See L<perlsub/"Overriding Built-in Functions">. There's
also an example in L<perltoot/"Class::Template">.
If you want to overload a Perl operator, such as C<+> or C<**>,