The new signatures are documented in perlsub since 5.20, under Signatures.

The same, or a rather similar functionality can be enabled employing a source filter, but I think that the failure modes of a source-filter (introducing hard to debug syntax errors) are not really worth the nicer syntax for older Perl versions.

In reply to Re: Using Shift with Parameters in a subroutine by Corion
in thread Using Shift with Parameters in a subroutine by perlron

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