using System;
using System.Runtime.InteropServices;

namespace MarshalDelegateError
{
    public class Test1
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        public delegate IntPtr MyDelegateOne(IntPtr a, IntPtr b, IntPtr c);
    }

    public class Test2
    {
        [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
        public delegate IntPtr MyDelegateTwo(IntPtr a, IntPtr b, IntPtr c);
    }

    class Program
    {
        private static IntPtr MyTestFunc(IntPtr a, IntPtr b, IntPtr c)
        {
            return a;
        }

        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");
            IntPtr ptr = Marshal.GetFunctionPointerForDelegate((Test1.MyDelegateOne)MyTestFunc);

            var d1 =(Test1.MyDelegateOne) Marshal.GetDelegateForFunctionPointer(ptr, typeof(Test1.MyDelegateOne));
            var d2 = (Test2.MyDelegateTwo)Marshal.GetDelegateForFunctionPointer(ptr, typeof(Test2.MyDelegateTwo));
            Console.WriteLine("Bug was not reproduced!");
        }
    }
}