title: How do I wrap a C++ interface (abstract class) in C++/CLI?
body: <p>I have some C++ code:</p>
  
  <pre><code>namespace Compute {   
    class __declspec(dllexport) IProgressCB {   
    public:     
      virtual void progress(int percentCompleted) = 0;   
    };    
    double __declspec(dllexport) compute(IProgressCB *progressCB, ...); 
  }
  </code></pre>
  
  <p>that I need to call from C#.<br>
  Therefore I want to wrap this C++ code in C++/CLI. </p>
  
  <p>I understand how to wrap the compute() function,
  but how do I wrap the IProgress interface?</p>
  
  <p>(It seems it is not possible for a .Net class to inherit a C++ class?)</p>