title: Can managed and unmanaged C++/MFC be mixed in one dll?
body: <p>Previously we had software in MFC (VC6), VB6 and C# applications that needed to call the same engine written in C++ (and MFC).  The engine required C++ for speed.  At the time we decided to use COM as the interface because all three could use it with the least issues in marshalling, etc.</p>
  
  <p>Our MFC application is now deprecated and we have recently decided to dump VB6, so what we've got left is C#.</p>
  
  <p>We can just leave the COM engine as-is, but it would be nice to get away from COM registration, etc., and have a managed interface to work with.  COM registration occasionally causes support issues if there is something wrong with the person's machine.</p>
  
  <p>Is it possible to have a dll with the existing unmanaged C++/MFC, and a .NET front end interface?</p>