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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++/94033] [10 Regression]
 is_trivially_copy_constructible<> fails with compiler error on complicated
 object with private default constructor
Date: Thu, 12 Mar 2020 16:38:59 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94033

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=3D94003

--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #11)
> #ifdef FIX
> static_assert( !std::is_nothrow_default_constructible<mutation>::value );
> #endif

Or slightly simpler, just instantiate the trait that's giving the wrong ans=
wer,
which others depend on:

#ifdef FIX
static_assert( !std::is_constructible<mutation>::value );
#endif


See also PR 94003.

Anyway, I have a patch for the library traits to avoid the problem.=