title: declaration or statement expected javascript/typescript
body: <p>I am using Typescript 1.7 and React 0.14 with the new ES6 systax and I'm having the following destructuring assignment, as explained <a href="https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment" rel="noreferrer">here</a> as well. </p>
  
  <pre><code>let x0, x1, y0, y1;
  if(this.props.viewport) {
      {x0, x1, y0, y1} = this.props.viewport;
  }
  </code></pre>
  
  <p>However, I'm getting the <code>Declaration or statement expected</code> error. What am I doing wrong?</p>
  
  <p>Thanks</p>