title: How to use mapState function in typescript syntax when using vuex?
body: <p>I'm using typescript syntax in my vuejs project that integrated with vuex.
  I want to use mapState method as computed in my .ts file but I got a syntax error.
  Currently I am using docs suggested syntax for computed function, I mean:</p>
  <pre><code> get counter() {
     return  this.$store.state.count;
   }
  </code></pre>
  <p>If you read the Vuex docs you will see that using Vuex in this way instead of using <code>mapState</code> is very repetitive. Using <code>mapState</code> is very easy and useful in large applications. I want to use <code>mapState</code> in my Typescript component and I don't know the right way. I've tried the way below to use the <code>mapState</code> function and it didn't work.</p>
  <pre><code>get mapState({
    counter:count
  });
  
  // or
  
  get mapState(['name', 'age', 'job'])
  </code></pre>
  <p>I'd be grateful if someone could help me.</p>