On 24 Apr 2025 11:22, Jonathan Wakely wrote:
>
> On Thu, 24 Apr 2025, 08:56 Andrey Semashev via Std-Proposals, <std-
> proposals_at_[hidden] <mailto:std-proposals_at_[hidden]>> wrote:
>
> I often find std::optional a disappointment in practice. In objects with
> lots of std::optional members,
>
> That isn't the situation that was given as motivation by the OP though.

The motivation presented by the proposal author doesn't have to be
exhaustive. Other people may have other reasons to find the proposal
useful. I just gave one.

> it nearly doubles the object size due to
> padding, and I often find myself replacing it with separate T members
> and bools or even std::bitset. This is, of course, tedious and requires
> discipline on the user. It also needs T to be cheaply constructible,
>
> Why? You would construct it with nullopt to avoid the default construction.

Again, that would entail all the costs of std::optional with it. And I
just said that those costs can be unacceptable.

> and
> could benefit from a proposal like this one.
>
> I don't really see how.

The benefit would be the ability to cheaply construct an object that
would otherwise be expensive to construct.