sigTParams: tparams,
			}
		}

		for i := 0; i < tparams.Len(); i++ {
			tparam := tparams.At(i)
			hash += 7 * h.Hash(tparam.Constraint())
		}

		return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results())

	case *types.Union:
		return h.hashUnion(t)

	case *types.Interface:
		// Interfaces are identical if they have the same set of methods, with