This has the interesting effect of creating a function local to another
function, something not normally supported in Perl.
-=head1 WARNING
+=head1 WARNING: Don't use references as hash keys
X<reference, string context> X<reference, use as hash key>
You may not (usefully) use a reference as the key to a hash. It will be
The standard Tie::RefHash module provides a convenient workaround to this.
-=head1 Postfix Dereference Syntax
+=head2 Postfix Dereference Syntax
Beginning in v5.20.0, a postfix syntax for using references is
available. It behaves as described in L</Using References>, but instead
in interpolating strings (double quotes or the C<qq> operator), but only
if the C<postderef_qq> L<feature> is enabled.
-=head1 Assigning to References
+=head2 Assigning to References
Beginning in v5.22.0, the referencing operator can be assigned to. It
performs an aliasing operation, so that the variable name referenced on the