sub mk_data_accessors3 {
	my $path = shift;
	for my $name (@_) {
		my $accessor = sub {
			carp "Warning: '$name' takes at most 2 arguments...\n" if @_ > 2;
			my $self = shift;
			$self->{$path}{$name} = shift if @_;
			return $self->{$path}{$name};
		};
		# keep the scope of "no strict" as small as possible
		no strict 'refs';  # needed for *$name
		*$name = $accessor;  # install the sub
	}
}

mk_data_accessors3('data','bar');

print bar({data=>{bar=>456}}), "\n";  # 456