https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77691
--- Comment #33 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I've been working on this again, and I think that the resource_adaptor type is
the wrong place to fix the malloc alignment problem.
The correct fix is to adjust the value of __STDCPP_DEFAULT_NEW_ALIGNMENT__ on
targets where malloc doesn't agree with GCC's alignof(max_align_t). Otherwise
even if I make resource_adaptor work for those targets, this test will still
fail:
#include <memory>
#include <cstddef>
#include <cstdint>
#include <assert.h>
template<typename T>
inline bool aligned(void* p)
{ return (reinterpret_cast<std::uintptr_t>(p) % alignof(T)) == 0; }
int
main()
{
using test_type = std::max_align_t; // largest fundamental alignment
std::allocator<test_type> a;
for (int i = 0; i < 10; ++i)
{
test_type* p1 = a.allocate(1);
VERIFY( aligned<test_type>(p1) );
test_type* p2 = a.allocate(20);
VERIFY( aligned<test_type>(p2) );
a.deallocate(p1, 1);
a.deallocate(p2, 20);
}
}
If we make std::allocator<max_align_t> work then the tests for resource_adaptor
will also work, at least on Solaris.
