Interesting set of implementation properties.

What is the goal? Why would we want this? (I can guess some answers, but
this is missing from your proposal)

How does this interact with overloading? What happens if you take the
address of such a function and never call it, what happens if you
instantiate a template with the address of it?

Regards,
Peter

On Tue, Mar 18, 2025 at 10:47 AM Samuel Alonso Rodríguez via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> This attribute is meant to be used in function (member or free, static or
> non-static, template or non-template) declarations to indicate that the
> function declaration is left unimplemented (without a definition) with an
> additional diagnostic message that can be fixed or opt-in thru an
> unevaluated string literal.
>
> The interesting bit comes from its behaviour: defining any function
> marked with such attribute, lleads to an ill-formed program (preferably
> with a diagnostic message), making calls to it be always diagnosable in
> non-linking time, because no TU can ever define this.
>
> The only catch so far is: redeclarations w/o this attribute would break
> that assumption. I thought of straight banning redeclarations but I think
> that’s too much. Maybe forcing redeclarations to have this attribute
> aswell, once the former declaration has it, could be an interesting idea to
> explore.
>
> What do you all think?
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