Everything is mutable. Builtin operators like assignment and equality are hardcoded and may behave badly for user-defined types. It doesn’t have subtypes; you c

Everything is mutable. Builtin operators like assignment and equality are hardcoded and may behave badly for user-defined types. It doesn’t have subtypes; you can slice to an embedded value but can’t get from there back to the containing struct or its methods. It doesn’t have generic covariance and contravariance; you can’t decide whether a []Animal or a []Bulldog is acceptable in place of a []Dog.