Removing the allocator<void> specialization for the versioned namespace
breaks _Extptr_allocator<void> because the allocator<void>
specialization was still declared in <bits/memoryfwd.h>, making it an
incomplete type. It wrong to remove that specialization anyway, because
it is still needed pre-C++20.
This removes the #if ! _GLIBCXX_INLINE_VERSION check, so that
allocator<void> is still explicitly specialized for the versioned
namespace, consistent with the normal unversioned namespace mode.
To make _Extptr_allocator<void> usable as a ProtoAllocator, this change
adds a default constructor and converting constructor. That is
consistent with std::allocator<void> since C++20 (and harmless to do for
earlier standards).
I'm also explicitly specializing allocator_traits<allocator<void>> so
that it doesn't need to use allocator<void>::construct and destroy.
Doing that allows those members to be removed, further simplifying
allocator<void>. That new explicit specialization can delete the
allocate, deallocate and max_size members, which are always ill-formed
for allocator<void>.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/alloc_traits.h (allocator_traits): Add explicit
specialization for allocator<void>. Improve doxygen comments.
* include/bits/allocator.h (allocator<void>): Restore for the
versioned namespace.
(allocator<void>::construct, allocator<void>::destroy): Remove.
* include/ext/extptr_allocator.h (_Extptr_allocator<void>):
Add default constructor and converting constructor.
754fca77e8