*mysub = sub : prototype(\@\@) ($left,$right) { ... };

##</code><code>##

use strict;
use warnings;
no warnings 'experimental::signatures';
use feature qw/say signatures/;
use List::Util qw(all);

BEGIN {
  
  ( *array_numeq,*array_streq )
    = map {
      my $compare = $_;
      sub :prototype(\@\@) ($l,$r) {
        @$l == @$r &&
        all { $compare->($l->[$_],$r->[$_]) } 0 .. $#$l
      }
    } sub { shift == shift }, sub { shift eq shift }

}

my @left  = ( 1, 2, 3 );
my @right = ( 1, 2, 3 );

{
  local $" = ',';
  say "(@left) ",
      ( array_numeq @left, @right ) ? "matches" : "doesn't match",
      " (@right)";
}

##</code><code>##

Array found where operator expected at mytest2.pl line 14, at end of line
	(Missing operator before ?)
syntax error at mytest2.pl line 14, near "@\@) "
Global symbol "$l" requires explicit package name at mytest2.pl line 14.
Global symbol "$r" requires explicit package name at mytest2.pl line 14.
Global symbol "$l" requires explicit package name at mytest2.pl line 15.
Global symbol "$r" requires explicit package name at mytest2.pl line 15.
Global symbol "$l" requires explicit package name at mytest2.pl line 16.
Global symbol "$r" requires explicit package name at mytest2.pl line 16.
Global symbol "$l" requires explicit package name at mytest2.pl line 17.
BEGIN not safe after errors--compilation aborted at mytest2.pl line 17.

##</code><code>##

use strict;
use warnings;
no warnings 'experimental::signatures';
use feature qw/say signatures/;
use List::Util qw(all);

BEGIN {
  
  ( *array_numeq,*array_streq )
    = map {
      my $compare = $_;
      + sub :prototype(\@\@) ($l,$r) {
        @$l == @$r &&
        all { $compare->($l->[$_],$r->[$_]) } 0 .. $#$l
      }
    } sub { shift == shift }, sub { shift eq shift }

}

my @left  = ( 1, 2, 3 );
my @right = ( 1, 2, 3 );

{
  local $" = ',';
  say "(@left) ",
      ( array_numeq @left, @right ) ? "matches" : "doesn't match",
      " (@right)";
}

##</code><code>##

my $subref = do{
  sub : prototype($) ($s) { return $s; };  # Perl thinks sub: is a label here.
};