Well, yes and no.

Eg cloning a string leads to an extra allocation and a memcopy.

If you want to get a similar performance profile to GC languages, you have to stick your types behind a `Rc<T>>/Arc<T>` or `Rc<RefCell<T>> / Arc<Mutex<T>>` if you need mutability.

But modern allocators hold up pretty well to a GC, which amortizes the allocations. The extra memcopying can be less detrimental than one might think.

“Yes and no” is too generous; most languages clone only very infrequently (basically only for primitives where there is no distinction between a deep and shallow copy). For complex types (objects and maps and lists) they pass references (sometimes “fat” references, but nevertheless, not a clone).