$ perl -MO=Deparse,-p -e 'sub ff($$){ qq{@_} } my %f = ( 12 => ff 1,2, 34 => ff 3,4 );'
Too many arguments for main::ff at -e line 1, near "4 )"
-e had compilation errors.
sub ff ($$) {
    "@_";
}
(my(%f) = (12, &ff(1, 2, 34, ff(3, 4))));