title: Communicating between C# and Visual C++ over IPC port (OR: Sharing a type between a Visual C++ DLL and a C# application)
body: <p>I have a DLL written in Visual C++ and an application written in C#.  The application that is written in C# already uses IPC between multiple instances of itself so that it only ever runs one instance (it attempts to start an IPC server, and if it can't assumes there's already one running, in which case it sends the command line arguments over IPC to the existing application).</p>
  
  <p>Now I want to send commands from a Visual C++, however, even when I create a type definition in Visual C++ that matches the one in C# (on an implementation level), it rejects the connection because they are fundamentally still two different types (from two different assemblies).</p>
  
  <p>I thought about using Reflection in Visual C++ to fetch the type from the C# assembly, but I can't do that because then I'd have to ship the assembly along side the DLL (which defeats the purpose of the DLL being an API to the application).</p>
  
  <p>I'm not sure of any other way I could really do it, other than store the class in yet another DLL and make both the application and the API DLL reference the class in that, but this is also not an ideal solution as I'd like a single API DLL to distribute.</p>
  
  <p>Are there any suggestions as to how I can connect over IPC (other forms of communication like TCP are not permitted) to send requests to the application?</p>