[Bug libstdc++/96803] std::tuple chooses wrong constructor for uses-allocator construction

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96803

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <redi@gcc.gnu.org>:

https://gcc.gnu.org/g:7825399092d572ce8ea82c4aa8dfeb65076b0e52

commit r11-3348-g7825399092d572ce8ea82c4aa8dfeb65076b0e52
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Sep 22 08:42:18 2020 +0100

    libstdc++: Use correct argument type for __use_alloc, again [PR 96803]

    While backporting 5494edae83ad33c769bd1ebc98f0c492453a6417 I noticed
    that it's still not correct. I made the allocator-extended constructor
    use the right type for the uses-allocator construction detection, but I
    used an rvalue when it should be a const lvalue.

    This should fix it properly this time.

    libstdc++-v3/ChangeLog:

            PR libstdc++/96803
            * include/std/tuple
            (_Tuple_impl(allocator_arg_t, Alloc, const _Tuple_impl<U...>&)):
            Use correct value category in __use_alloc call.
            * testsuite/20_util/tuple/cons/96803.cc: Check with constructors
            that require correct value category to be used.