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Re: [SG15] [isocpp-modules] Determining identity like #pragma once

From: Tom Honermann <tom_at_[hidden]>
Date: Wed, 10 Jul 2019 15:13:21 -0400
On 7/10/19 3:11 PM, Ville Voutilainen wrote:
> On Wed, 10 Jul 2019 at 22:09, Ville Voutilainen
> <ville.voutilainen_at_[hidden]> wrote:
>> On Wed, 10 Jul 2019 at 22:06, Tom Honermann <tom_at_[hidden]> wrote:
>>> You are implying that the include translation is mandatory. Is that your argument?
>>> Yes. The wording in [cpp.include]p7 seems fairly clear regarding that.
>> Not at all. "If the header identified by the header-name denotes an
>> importable header" is implementation-defined. The set
>> of importable headers is allowed to be whatever the implementation
>> decides, including an empty set. The library specification
>> might change that for some library headers, but in general, it doesn't
>> seem to me that include translation is mandatory
>> for #include. If you import a header, it must be importable, but
>> #including it doesn't require that, based on what the spec says.
> ..however, having said all that, it doesn't seem to me that you can
> get to the problematic situation with a well-formed program,
> either, because if the header isn't importable, importing it violates
> a shall-requirement and is thus ill-formed, in Core-speak.
> And if you can import it, #including it will also import it. Pardon
> the possible confusion caused by the earlier.



Received on 2019-07-10 14:15:16