title: Pairs as hash keys
body: <p>Does anyone know how to make a hash with pairs of strings serving as keys in perl?</p>
  
  <p>Something like...</p>
  
  <pre><code>{
      ($key1, $key2) =&gt; $value1;
      ($key1, $key3) =&gt; $value2;
      ($key2, $key3) =&gt; $value3;
  </code></pre>
  
  <p>etc....</p>