❔ ✅ Generics 'where' : Limitations of what types are allows

class A {}
class B : A {}
class A2 : A {}
class B2 : B {}


// I want to say that T1 is *not* allowed to be a subclass of B
void DoSomething<T1, T2>(T1 val1, T2 val2)
  where T1 : A
  where T2 : B
{}

// I want to say that T1 and T2 are not allowed to be the same type
void DoSomethingElse<T1, T2>(T1 val1, T2 val2)
  where T1 : A
  where T2 : A
{}