#!/usr/bin/perl -w
use strict;
use Data::Dumper;
my $s = {
	 foo =>'bar',
	 baz => {
		 troz  => 'zort',
		 blort => {
			   poit => 'qux',
			  }
		}
	};

print Dumper $s;
# This works in 5.6.1 and later
set($s, qw/baz blort poit/) = "Whee!";
set($s, qw/baz troz/) = "Joy!";
# In 5.6.0 (and earlier) you have to:
# set($s, qw/baz blort/)->{poit} = "Whee!";
# set($s, qw/baz/)->{troz} = "Joy!";
print Dumper $s;

sub set : lvalue {
  @_ == 1 ? $_[0] : set($_[0]{$_[1]},@_[2..$#_]);
}