title: c# extension for indexer
body: <p>I would like to write an extension for DataRow indexer so I can do something like this:</p>
  
  <pre><code>MyCustomClass myClass;
  DataRow[myClass] = 5;
  </code></pre>
  
  <p>I found this related question: <a href="https://stackoverflow.com/questions/7286181/c-sharp-extend-indexer">C# extend indexer?</a></p>
  
  <p>However the question was asked 7 years ago and maybe we can extend indexers now?</p>
  
  <p>Also in the <a href="https://blog.todotnet.com/2017/09/sneak-peek-at-c-8/" rel="nofollow noreferrer">C# 8 sneak preview</a> they mentioned "Extension Everything"</p>
  
  <blockquote>
    <p>For version 8 some features are in prototype status, some are just
    concepts. The first four features that should make it to version 8 of
    C# are:</p>
  
  <pre><code>* Nullable Reference Types
  * Async Streams
  * Default Interface Methods
  * Extension Everything
  </code></pre>
  </blockquote>
  
  <p>Maybe I should wait for C# 8 to hit?</p>