> The first is an actual mutation of memory. The second is an allocation of new memory. The old memory is unaffected. One could argue that this is a form of mut

> The first is an actual mutation of memory. The second is an allocation of new memory. The old memory is unaffected. One could argue that this is a form of mutation. This mutation, however, is syntactic. It's not purely syntactic. You aren't mutating the referent of a pointer. You're mutating the referent of a scoped variable name. That saves you from certain swathes of bugs (in concurrent code), but it's still something you want to use sparingly. Reasoning about any kind of mutability, even in single-threaded code, isn't the easiest thing in the world.