> On 21 Mar 2025, at 10:56, Ville Voutilainen <ville.voutilainen_at_[hidden]> wrote:
>
> On Fri, 21 Mar 2025 at 11:48, Hans Åberg <haberg_1_at_[hidden]> wrote:
>>>> No, it is for compiler writers to mark what is not implemented, instead of doing nothing or using “delete”. See the example I gave upthread.
>>>
>>> If a compiler writer wanted a facility like this, they would already
>>> be using it.
>>
>> Indeed, we haven't heard anything from any actual C++ compiler writers in this thread I would think.
>
> You just did hear from one.

Great. There are some others I noticed didn't appear in this thread.

I think though interesting, at least from the theoretical point of view, having a feature that the one definition rule means that one can by some policy choose which one to use, a user extension to what is already supplied for global operator new, and “inline”.