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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/96710] New: __int128 vs <type_traits>
Date: Wed, 19 Aug 2020 15:08:58 +0000	[thread overview]
Message-ID: <bug-96710-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96710

            Bug ID: 96710
           Summary: __int128 vs <type_traits>
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

In strict modes (e.g. -std=c++17) the __int128 type does not belong to any of
the standard type categories, because is_integer<__int128> is false, which
means is_arithmetic<__int128> is false.

Our definitions of is_scalar depends on is_arithmetic, so is_scalar<__int128>
is false, and therefore is_object<__int128> is false. This is clearly nonsense.

We should fix this, so that even when is_integer<__int128> is false, we can
still give sensible answers for __int128 that do not (unsucessfully) try to
deny its existence.

Of course the ideal would be for WG14 to accept
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2425.pdf and then we can just
say is_integer<__int128> is true even in strict modes and everybody rejoices.

             reply	other threads:[~2020-08-19 15:08 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-19 15:08 redi at gcc dot gnu.org [this message]
2020-12-10 15:30 ` [Bug libstdc++/96710] " redi at gcc dot gnu.org
2022-05-18 12:42 ` redi at gcc dot gnu.org
2024-02-06 11:12 ` redi at gcc dot gnu.org

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