1137583 - mozilla::IsPointer does not work on CV-qualified pointers like std::is_pointer

Status: RESOLVED FIXED

(Core :: MFBT, defect)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Spawned from bug 1131445 comment 12.

Reading the standard, 20.9.4.1-2 (related to std::is_pointer and other primary type categories):

"""
For any given type T, the result of applying one of these templates to T and to cv-qualified T shall yield the same result.
"""

The current implementation of mozilla:IsPointer doesn't match std::is_pointer.

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Attachment: 1137583-IsCVPointer.patch

Fix for IsPointer to work with CV-qualified pointers.
Added tests.

Comment 2

[Jeff Walden [:Waldo]]

Comment on attachment 8570841 [details] [diff] [review]
1137583-IsCVPointer.patch

Review of attachment 8570841 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good with the ordering fix.  No need for me to review that, just post a new version of the patch with that change made to it and flag it for checkin the usual way.  (Probably best if someone else does it than me -- I usually do for patches I review, but my queue is not in great shape to land things very soon right now.)

::: mfbt/tests/TestTypeTraits.cpp
@@ +8,5 @@
>  #include "mozilla/TypeTraits.h"
>  
>  using mozilla::AddLvalueReference;
>  using mozilla::IsArray;
> +using mozilla::IsPointer;

Actually, on second look -- move this down after |using mozilla::IsLvalueRference;| to preserve alphabetical order.

Comment 3

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=b88981f9e32c

Comment 4

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Attachment: 1137583-IsCVPointer.patch

Changes as recommended (cosmetic only).

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1c64893b5fdd

Comment 6

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/1c64893b5fdd