sub typeck
{
    my ($what, $type) = @_;
    if (!UNIVERSAL::isa($type, 'ARRAY')) { croak 'Type not an array reference' }

    not grep { !$_ } ( map {
	grep { $_ }
	     ( (index($_, '/') == 1 and rindex($_, '/') == (length($_) - 1) and do
	       {
		   my $rex = substr($_, 1, length($_) - 1);
		   (ref($what) eq '') ? ($what =~ $rex) : ((Denter $what) =~ $rex);
	       }),
	      (UNIVERSAL::isa($_, 'ARRAY') &&
	       do
	       {
		   my $type = $_;
		   not grep {!$_}
		   (map { typeck ($_, $type) } ((UNIVERSAL::isa($what, 'ARRAY'))
						    ? @$what : values(%$what)));
	       }),
	      (UNIVERSAL::isa($_, 'HASH') &&
	       do
	       {
		   my $type = $_;
		   not grep {!$_}
		   (map { exists ($type->{$_}) } (keys %$what));
	       }),
	      (UNIVERSAL::isa($_, 'CODE') && $_->($what)),
	      (UNIVERSAL::isa($what, $_))) } (@$type));
}