Why are all Delegate types incompatible with each other?

Question

In C# all delegate types are incompatible with one another, even if they have the same signature. As an example:

delegate void D1();
delegate void D2();

D1 d1          


        

Answer 1

Basically because the compiler makes two classes for you. The same reason you can't do:

class A {}
class B {}

void Main()
{
    A a = new A();
    B b = a;
}

---

For example, the following code

void Main() {}

delegate void D();
class C {}

The IL code is:

D.Invoke:

D.BeginInvoke:

D.EndInvoke:

D..ctor:

C..ctor:
IL_0000:  ldarg.0     
IL_0001:  call        System.Object..ctor
IL_0006:  ret