> What can we assume about the alignment about the default operator new > (the one without alignment supplied)? Is it the same as malloc or > something different?
My reading of https://eel.is/c++draft/expr.new#17 suggests that "new unsigned char[]" etc. must preserve whatever fundamental alignment the allocation function gave it ("the difference between..."), and the standard clearly intends you to be able to use that to allocate storage for any non-overaligned object. So I'm pretty sure the same rules should apply as to malloc.
