=over =item __SUB__ X<__SUB__> A special token that returns a reference to the current subroutine, or L<C<undef>|/undef EXPR> outside of a subroutine. The behaviour of L<C<__SUB__>|/__SUB__> within a regex code block (such as C</(?{...})/>) is subject to change. This token is only available under C<use v5.16> or the L<C<"current_sub"> feature|feature/The 'current_sub' feature>. See L<feature>. =back