placement new + array +alignment

Question

SomeObj* Buffer;
char* BufferPtr = MemoryManager::giveMeSomeBytes(resX*resY*sizeof(SomeObj));
Buffer = new(BufferPtr) SomeObj         


        

Answer 1

@Mat, This is actually a great question. When I've used placement new[], I've had trouble deleting the storage. Even if I call my own symmetrical placement delete[], the pointer address is not the same as was returned by my own placement new[]. This makes placement new[] completely useless, as you've suggested in the comments.

The only solution I've found was suggested by Jonathan@: Instead of placement new[], use placement new (non-array) on each of the elements of the array. This is fine for me as I store the size myself. The problem is that I have to worry about pointer alignments for elements, which new[] is supposed to do for me.