[Bug libstdc++/70472] is_copy_constructible<vector<unique_ptr<int>>>::value is true

[rs2740 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70472

TC <rs2740 at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |rs2740 at gmail dot com

--- Comment #5 from TC <rs2740 at gmail dot com> ---
In any event, it would be wrong to SFINAE on
std::is_copy_constructible<value_type>. The requirement is CopyInsertable, not
CopyConstructible. The allocator's construct() can mutilate the constructor
arguments to its heart's content before passing them on, and I don't see a way
to check this.