I got tripped up on that statement, too. The problem is that tinus_hn's parent comment started with a false premise: that the only way to return memory to the

I got tripped up on that statement, too. The problem is that tinus_hn's parent comment started with a false premise: that the only way to return memory to the OS is by moving memory around, which is not the case. I think CJefferson was saying that manual memory allocators can't move memory around (which in the general case is true, but you point out in a different thread there are cases when it can), because the rest of their comment is explaining how they can return memory.