[polymathist]

Yes, I've already been thinking about constraining type parameters to an interface. Internally, the type-checker considers type parameters to have underlying type interface {}. A constraint on a type parameter should be as straightforward as changing it's underlying type to a specific named interface instead of an empty one. The only tricky bit I can see is thinking about how this would work with generic interfaces or whether we should allow other kinds of type constraints (e.g., union types).

[leshow]

If it considers parametric types to be interface {}, is that a kind of type erasure? I don't know much about Go, but it's my understanding that interface {} types have an extra layer of indirection and are essentially just pointers.