Date: Sun, 12 Jul 2020 21:45:16 +0200
On 12/07/2020 20.05, Ben Craig via SG10 wrote:
> https://isocpp.org/files/papers/P2198R0.html
>
> While writing examples for feature-test usage in freestanding, I discovered how much of a pain it is to detect extensions to freestanding. The above paper makes that detection possible and makes policy recommendations for future papers. In order to fix the problem, I ended up bumping the version on _all_ the library feature test macros.
>
> Let me know what you think, and then we can figure out if we need an SG10 telecon to discuss this.
Uh.. no.
It seems that freestanding implementations that ship a <version> header
with those feature-test macros present that represent features not
available on their platform (e.g. std::filesystem) are actively misleading
and violating the spirit of the feature-test macros.
If the current wording allows or requires such macros for freestanding,
the standard is buggy and needs to be DR-fixed.
Jens
> https://isocpp.org/files/papers/P2198R0.html
>
> While writing examples for feature-test usage in freestanding, I discovered how much of a pain it is to detect extensions to freestanding. The above paper makes that detection possible and makes policy recommendations for future papers. In order to fix the problem, I ended up bumping the version on _all_ the library feature test macros.
>
> Let me know what you think, and then we can figure out if we need an SG10 telecon to discuss this.
Uh.. no.
It seems that freestanding implementations that ship a <version> header
with those feature-test macros present that represent features not
available on their platform (e.g. std::filesystem) are actively misleading
and violating the spirit of the feature-test macros.
If the current wording allows or requires such macros for freestanding,
the standard is buggy and needs to be DR-fixed.
Jens
Received on 2020-07-12 14:48:38