Is there a mainstream language where this still holds true?
From what I've seen most languages don't want to have a Turing complete type system, but end up with one anyway. It doesn't take much, so it's easy to end up with it accidentally and/or by adding conveniences that don't seem programmable, e.g. associated types and type equality.
From what I've seen most languages don't want to have a Turing complete type system, but end up with one anyway. It doesn't take much, so it's easy to end up with it accidentally and/or by adding conveniences that don't seem programmable, e.g. associated types and type equality.