title: How can I iterate over a custom literal type in TypeScript?
body: <p>I have defined a custom literal type in TypeScript:</p>
  <pre><code>export type Market = 'au'|'br'|'de';
  </code></pre>
  <p>Now I want to iterate over each possible <code>Market</code> without having to create an array of <code>Market[]</code> in the first place as it <em>feels</em> redundant and I may forget to add one option:</p>
  <pre><code>const markets: Market[] = ['au', 'br', 'de'];
  markets.forEach((market: Market) =&gt; {
      console.log(market);
  });
  </code></pre>
  <p>Is there a way to achieve that with TypeScript?</p>