title: Typescript: Retrieve element type information from array type
body: <p>Say I have some array type <code>T[]</code>, is it possible to extract the type <code>T</code> within another alias / interface? For example my (fake) ideal code would be as follows: </p>
  
  <pre><code>// for illustration only...
  
  type ArrayElement&lt;T[]&gt; = T;
  
  // then, ArrayElement&lt;string[]&gt; === string
  </code></pre>
  
  <p>If no, are there general type theory reasons for not allowing such an operator? If no again, I might suggest it be added.</p>
  
  <p>Thanks!</p>