[Bug libstdc++/70940] pmr::resource_adaptor requires optional allocator requirements and incorrectly aligns returned pointers.

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70940

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Thu Jun 21 14:01:11 2018
New Revision: 261849

URL: https://gcc.gnu.org/viewcvs?rev=261849&root=gcc&view=rev
Log:
PR libstdc++/70940 make pmr::resource_adaptor return aligned memory

        PR libstdc++/70940
        * include/experimental/memory_resource (__resource_adaptor_common):
        New base class.
        (__resource_adaptor_common::_AlignMgr): Helper for obtaining aligned
        pointer from unaligned, and vice versa.
        (__resource_adaptor_imp::do_allocate): Use _AlignMgr to adjust
        allocated pointer to meet alignment request.
        (__resource_adaptor_imp::do_deallocate): Use _AlignMgr to retrieve
        original pointer for deallocation.
        (__resource_adaptor_imp::do_is_equal): Reformat.
        (__resource_adaptor_imp::_S_aligned_size): Remove.
        (__resource_adaptor_imp::_S_supported): Remove.
        (new_delete_resource): Use __gnu_cxx::new_allocator.
        * testsuite/experimental/memory_resource/resource_adaptor.cc: Test
        extended alignments and use debug_allocator to check for matching
        allocate/deallocate pairs.

Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/experimental/memory_resource
   
trunk/libstdc++-v3/testsuite/experimental/memory_resource/resource_adaptor.cc