package Sub::Prototype::Util;
+use 5.006;
+
use strict;
use warnings;
Flattens the array C<@args> according to the prototype C<$proto>.
When C<@args> is what C<@_> is after calling a subroutine with prototype C<$proto>, C<flatten> returns the list of what C<@_> would have been if there were no prototype.
+It croaks if the arguments can't possibly match the required prototype, e.g. when a reference type is wrong or when not enough elements were provided.
=cut