title: Mix c++ and c# in the same project inside Visual Studio Express 2015
body: <p>I have a piece of unmanaged native C++ code (one class) that I want to integrate into a C# .NET assembly.</p>
  
  <p>I (think) I know I have two options for doing this:</p>
  
  <ol>
  <li>pack my native C++ code into an unmanaged DLL and use PInvoke (DllImport, etc.) to load and run it from C# code;</li>
  <li>use C++/CLI to make a managed wrapper C++ class that in turn references my unmanaged native C++ class, for which I found some examples.</li>
  </ol>
  
  <p>Let's suppose I want to go for option 2 and use Visual Studio Express 2015 IDE GUI, without calling directly the compilers from command line.</p>
  
  <p>Do I need to make two separate projects for the two C# (project "C#") and C++/CLI-C++/native (project "C++") parts, then reference (add reference) the DLL output file of project "C++" from project "C#" and link it statically?
  Is this the only way or could C++ source files be integrated directly into project "C#" by specifying a different compiler and different compiler options for each of them?</p>