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Running C++ code from C# Dotnet Core

• HippoBaro 8y ago
  This is arguably not C++ interoperability, but C interop. Big difference there. The author conveniently doesn't show how to pass parameters (especially non-POCO objects), for example.
  • zamalek 8y ago
    Exactly. It should be theoretically be possible to call C++ via interop: [DllImport("<MANGLED NAME>")] static extern void Foo(IntPtr @this, int param1, ...);
    • sebazzz 8y ago
      That will only work on x64 I believe. x86 requires the this pointer to be passed in register ECX [0] [0]: https://docs.microsoft.com/en-us/cpp/cpp/thiscall https://docs.microsoft.com/en-us/cpp/cpp/thiscall
      • zamalek 8y ago
        I studied calling conventions too long ago, but wasn't ECX (registers and then stack, in general) stdcall on Windows? I could stand to absolute correction there, just curious.
  • snarfy 8y ago
    Yeah, I saw the title and was excited, then I saw #ifdef __cplusplus extern "C" { #endif This makes it C interop. If it were C++ interop, I would be able to DllImport a C++ library (without the C linkage) and get a C# wrapper class of the C++ classes automatically. It's not C#'s fault. C++ is the one without an ABI. To properly DllImport C++ you would need to define the so/dll name in the import and also the specific C++ compiler version and build, since the binary changes underneath, e.g. foo.msvc_x64_debug.dll, foo.gcc_x86_release.dll, etc. Then C# might have a chance of importing a c++ library, but not today.
    • sebazzz 8y ago
      > If it were C++ interop, I would be able to DllImport a C++ library (without the C linkage) and get a C# wrapper class of the C++ classes automatically. If you count COM as being C++, it would be possible.
  • thebillkidy 8y ago
    [Author] Thanks for pointing this out! Seeing I am quite new to this as well, I was not aware of this. Will check this out!