[ 2023-01-11; Jonathan Wakely provides improved wording ]

During LWG telecon Tim pointed out that because allocator<void> does not meet the Cpp17Allocator requirements, it might not "qualify as an allocator" and so would cause the deduction guides to not participate in overload resolution, as per [container.adaptors.general] p6 (6.4). Use allocator<byte> instead.