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From: "de34 at live dot cn" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/113200] std::char_traits<char>::move is not constexpr
 when the argument is a string literal
Date: Thu, 04 Jan 2024 01:58:50 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D113200

Jiang An <de34 at live dot cn> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |de34 at live dot cn

--- Comment #9 from Jiang An <de34 at live dot cn> ---
(In reply to Peter Dimov from comment #3)
> I think that the compiler is correct; string literal address comparisons
> aren't constant expressions. Clang gives the same error:
> https://godbolt.org/z/xPWEf4z63.

This looks weird... It seems that `+"abc" =3D=3D +"def"` is never unspecifi=
ed (must
be false, but Clang rejects it in constant evaluation), while `"abcd" + 1 =
=3D=3D
+"bcd"` is unspecified.

It's unclear to me whether we can practically detect all kinds of
unspecifiedness in pointer comparision involving string literals.=