Re: [PATCH] libstdc++: Fix compare_three_way for constexpr and Clang

[Paul Keir <Paul.Keir@uws.ac.uk>]

*ping*

________________________________________
From: Paul Keir <Paul.Keir@uws.ac.uk>
Sent: 03 September 2021 11:31
To: gcc-patches@gcc.gnu.org
Cc: libstdc++@gcc.gnu.org
Subject: Re: [PATCH] libstdc++: Fix compare_three_way for constexpr and Clang

*ping*

________________________________________
From: Paul Keir <Paul.Keir@uws.ac.uk>
Sent: 20 August 2021 21:17
To: gcc-patches@gcc.gnu.org
Cc: libstdc++@gcc.gnu.org
Subject: [PATCH] libstdc++: Fix compare_three_way for constexpr and Clang

Hi,

The current compare_three_way implementation makes provision for constant evaluation contexts (avoiding reinterpret_cast etc.), but the approach fails with Clang; when it compares two const volatile void pointers: "comparison between unequal pointers to void has unspecified result". I include a fix and test.

Could someone commit the attached patch for me?

Thanks,
Paul


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