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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++/102916] cmath constexpr can lead to ODR
 violations/incorrect results
Date: Wed, 30 Nov 2022 14:53:51 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102916

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |WONTFIX
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #12)
> This is EXTREMELY contrived. You've basically set up a program where you
> detect is std::sqrt is constexpr, and then said you get different results
> depending whether std::sq

... rt is constexpr. Well, yeah.

Don't do that then.

Nobody forces your code to check whether std::sqrt is constexpr, so just do=
n't.
And if your code really chooses between invoking feed_cat() and
launch_missiles() based on that condition, you're screwed in C++23 anyway.

So just don't do that.=