On Wed, 22 Jan 2025 at 20:45, Bo Persson via Std-Proposals
<std-proposals_at_[hidden]> wrote:

> append and push_back will work, but is pretty useless if you don't know
> what is in there beforehand. push_back will get you "one more than the
> unknown previous number". Hard to see where that will be useful, but it
> is still defined.

Well, for example, a push_back() followed by a use of back() always
works, regardless
of whether the container is moved-from.