title: Inheritance impossible in Windows Runtime Component?
body: <p>Scenario:<br>
  I have 3 classes (A,B,C) in my Windows Runtime Component project. </p>
  
  <pre><code>class A{}
  public sealed class B : A {}
  public sealed class C : A {}
  </code></pre>
  
  <p>On compiling the above code, I get the following <strong>error</strong>:  </p>
  
  <blockquote>
    <p>"Inconsistent accessibility: base class 'A' is less accessible than
    class 'C'."</p>
  </blockquote>
  
  <p>If I make class A public, it gives a <strong>compile error</strong> :  </p>
  
  <blockquote>
    <p>"Exporting unsealed types is not supported. Please mark type
    'MyProject.A' as sealed."</p>
  </blockquote>
  
  <p>But now, if I make A as sealed, then B and C cannot inherit from it.<br/></p>
  
  <p>Considering the fact that only WinRT types are allowed for inheritance, is it anyhow possible to use custom/user-defined classes for inheritance? If not, is there any workaround to achieve the same? </p>