title: Typescript Type Exclusion?
body: <p>I know of type union &amp; type intersection in type script but I couldn't find a syntax or workaround to use type exclusion. Is there a way to do that?</p>
  
  <pre><code>type ValidIndices = string ^ '_reservedProperty'; // All strings but '_reservedProperty'
  interface MyInterface {
      [property: ValidIndices]: number;
      _reservedProperty: any;
  }
  </code></pre>