In the type checker, our notion of type identity for signatures considers type parameters in the signature declaration identical if they have identical constraints. In other words, it ignores the type parameter names:

Identical(func[P ~int](){}, func[Q ~int](){}) == true

But we don't extend this type parameter identity when comparing parameters or results:

Identical(func[P ~int](P){}, func[Q ~int](Q){}) == false

This is most likely an oversight since it doesn't matter in type-checked code, but we should be consistent.

CC @griesemer