No: the idea that immutable is a sensible default, and active enforcing of immutability. In Java, e.g., a linked list's cell might be immutable, but its conten

No: the idea that immutable is a sensible default, and active enforcing of immutability. In Java, e.g., a linked list's cell might be immutable, but its contents are most likely mutable - so back to page one. It is definitely possible to write code for structures that are immutable by interface or convention, but the environment does not help you doing so.