Alignment in rawMemory function in utils.h

[yuval-khachatryan]

I think there are couple of issues with
struct EMPTY{}; template<typename ITEM> ITEM* rawMemory(int n = 1) {return (ITEM*)::operator new(sizeof(ITEM) * n);}

1. I think aligned new should be used - the correct version doesn't take alignment of Item into consideration. Correct me if I am wrong.
2. Not sure - but I think that attempting to use the returned pointer is UB for pretty much everything, including pointer arithmetic. (Not 100% sure, may be this case is covered by implicit-lifetime in C++20 standard), even though it should work in practice on all compilers, as far as I know.

[dkedyk]

Thx for reaching out.

This function allocates and array using placement new. I originally read about this in Dewhurst's book https://www.amazon.com/Common-Knowledge-Essential-Intermediate-Programming/dp/0321321928.

1. I did some research on this, and you may be right here. Though per https://stackoverflow.com/questions/8720425/array-placement-new-requires-unspecified-overhead-in-the-buffer a standard adjustment seems to fix the issue. I am not an expert on this. Any specific suggestion on how to fix this?
2. I think pointer arithmetic is fine, though I think I never use it in the book. The intention of this whole construct is to avoid calling constructors on all members of array on creation.