title: Type '{}' is not assignable to type 'string'
body: <p>I am using <strong>ngrx/router</strong>.</p>
  
  <p>When I open <code>http://localhost/set-new-password/abc</code>, the <code>RouteParams</code> works well. I can get the string <code>token</code> I want.</p>
  
  <pre><code>const landingRouter: Routes = [
    { path: '/set-new-password/:token', component: SetNewPasswordComponent },
  ];
  
  export class SetNewPasswordComponent implements OnInit {
    token: string = '';
  
    constructor(private _routeParams$: RouteParams) {}
  
    ngOnInit()
    {
      this._routeParams$
        .pluck('token')
        .subscribe(token =&gt; {
          console.log(typeof token); // Console: "string"
          console.log(token);        // Console: "abc"
          this.token = token;        // Terminal: Type '{}' is not assignable to type 'string'.
        });
    }
  }
  </code></pre>
  
  <p>However, I got this warning in my terminal:</p>
  
  <blockquote>
    <p>Type '{}' is not assignable to type 'string'.</p>
  </blockquote>
  
  <p>I know I can use <code>this.token = String(token);</code> to get rid of it.</p>
  
  <p>But why does this warning show? Can someone explain a little bit for me?  Thanks</p>