title: How to union two array references containing array references in perl?
body: <p>Let's say I have an array reference which looks like -</p>
  
  <pre><code>my $arrayref1 = [[1,2], [3,4], [5,6]];
  </code></pre>
  
  <p>and, I have another array reference as -</p>
  
  <pre><code>my $arrayref2 = [[1,2], [3,4], [7,8]];
  </code></pre>
  
  <p>How do I achieve something like this -</p>
  
  <pre><code>push @{$arrayref1}, @{$arrayref2};
  </code></pre>
  
  <p>such that arrayref1 will look like this (excluding array references containing common elements) -</p>
  
  <pre><code>$arrayref2 = [[1,2], [3,4], [5,6], [7,8]];
  </code></pre>