Overriding “equals” method: how to figure out the type of the parameter?

Question

I\'m trying to override equals method for a parameterized class.

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return t         


        

Answer 1

Off-topic - do you realise that according to your implementation, Tuple(a0, a1) is equal to Tuple(a1, a1)? I suspect that's not what you want...

On-topic, as others have said, erasure makes this impossible. But you should reconsider why you want this - equality checking only happens at runtime, and generics are only compile-time. Conceptually, a variable has generic parameters, but an object does not. Thus when you're comparing the equality of objects, the generic parameters do not matter at all; you can't take any appropriate action based on them at runtime anyway.

Object equality, and generic parameter co-/contra-variance, are two orthogonal concerns.