Is the conversion from bytes to Vec<u8> O(1)

[cBournhonesque]

Is the conversion from bytes to Vec O(1) if the underlying memory is already contiguous and the ref count is 1?

Or do we still have new allocations and copying?

I looked at https://github.com/tokio-rs/bytes/pull/547, it seems to suggest that it indeed is O(1) but the docs say

Copies self into a new Vec.