operation is not found. Three different cases are possible depending on
the value of C<"fallback">:
-=head2 Smart Match
-
-The key C<"~~"> allows you to override the smart matching used by
-the switch construct. See L<feature>.
-
=over 16
=item * C<undef>
B<Note.> C<"fallback"> inheritance via @ISA is not carved in stone
yet, see L<"Inheritance and overloading">.
+=head2 Smart Match
+
+The key C<"~~"> allows you to override the smart matching used by
+the switch construct. See L<feature>.
+
=head2 Copy Constructor
The value for C<"="> is a reference to a function with three