将一个c++类编组到c#

I need to access code in a native C++ DLL in some C# code but am having issues figuring out the marshaling. I've done this before with code that was straight C, but seem to have found that it's not directly possible with C++ classes. Made even more complicated by the fact that many of the classes contain virtual or inline functions. I even tried passing the headers through the I need to access code in a native C++ DLL in so