title: kotlin generics and operator overloading
body: <p>I want to do some thing like this</p>
  
  <pre><code>data class TestGen&lt;T: Number&gt;(var x : T, var y : T)
  
  public operator&lt;T:Number&gt; fun Int.plus(p:TestGen&lt;T&gt;) = TestGen(this+p.x,p.y)
  </code></pre>
  
  <p>so how i can do it? or any other idea to do the same thing?
  becouse i want to do some thing like this</p>
  
  <pre><code>public operator fun Int.plus(p:TestGen&lt;Float&gt;) = TestGen(this+p.x,p.y)
  public operator fun Int.plus(p:TestGen&lt;Double&gt;) = TestGen(this+p.x,p.y)
  </code></pre>