I wouldn't consider Rust a manual memory environment. There are ways to do that at edges if needed, but it is otherwise very much automatic which is kind of the whole point of its design.
What most people mean when they say this is GC vs no GC. Rust is the latter. You have to care about ownership unless you're wrapping in Rc/Arc.
What most people mean when they say this is GC vs no GC. Rust is the latter. You have to care about ownership unless you're wrapping in Rc/Arc.