[patch] Fix libstdc++/51626

[Jonathan Wakely <jwakely dot gcc at gmail dot com>]

We don't have allocator_traits in 4.6 so this patch adds a test for
whether we can call allocator::construct(p) with a single argument and
calls _Construct(p) if not.

        PR libstdc++/51626
        * include/bits/stl_uninitialized.h (_Construct_default_a): Define
        overloaded functions to conditionally use allocator::construct.
        (_Construct_default_a): Define to dispatch to appropriate
        _Construct_default_a_impl overload.
        (__uninitialized_default_a, __uninitialized_default_n_a): Use
        _Construct_default_a.
        * testsuite/20_util/allocator/51626.cc

Tested x86_64-linux.

I plan to check this in to the 4.6 branch unless anyone has a better
suggestion for fixing the bug.

Attachment: 51626.txt
Description: Text document