API inconsistency

[ghost]

According to the https://doc.rust-lang.org/alloc/alloc/trait.Allocator.html#required-methods, Allocator::alocate on success returns NonNull<[u8]>, butAllocator::deallocate takes NonNull<u8> instead of NonNull<[u8]>. It looks inconsistent. Is it design problem or there are something that I misunderstood?

[CAD97]

So the reason for this is that the allocation size is given to deallocate in Layout. allocate returns NonNull<[u8]> because it could give you more memory than requested.

[ghost]

Thank you, that makes sense.