Frank Mori Hess wrote:
I wasn't following the thread too closely, but I assumed the benefit of using size+alignment instead of type would be that you could reuse the same allocator with different types (as long as they had the same size and alignment). But since a type's size+alignment varies across platforms, you wouldn't be able to portably reuse such an allocator with different types (hence no portable benefit).
The size + alignment wouldn't be part of the type of the allocator, it would be part of the arguments it receives to perform a given allocation. (i.e., like posix_memalign). But strictly speaking, the language doesn't even require to take into account arbitrary alignments, you can just align to anything big enough, like malloc and operator new do.