On Wednesday, 16 June 2021 at 02:46:36 UTC, cc wrote:
I can't seem to get it to work as a return type, but interestingly it does work as an out/pass by ref parameter.
Probably for returning the struct it needs some allocation directive in C# but I'm not sure. Maybe C# also tries something to do with the IntPtr. It may work if you use a struct on the DLL side too and convert any specific things like pointers to simple integers instead.
The out keyword however basically is just a pointer to the struct, so reading directly from the memory offset from the DLL works instead.
As long the GC sees the data alive - .(i)dup doesn't protect your memory here. The data could be collected by the GC anytime the function call goes out of scope.
