The author dismisses C++ out of hand, but I really think it does a pretty good job of making this a non-issue. Want a structured value type? Sure, that's a struct with public fields by default, passed by value with automatic copy constructor and assignment functions. Want a mutable type that's encapsulated and needs to do something special to be cloned? Sure, that's a class passed by unique_pointer or reference, with non-default (or deleted) copy constructor and assignment functions and private fields by default.

Every language I've used since then feels like it makes this issue needlessly complicated and implicit.