array new-expressions: proposal

[Jason Merrill]

It's really a question of which is more common: people wanting to delete[]
pointers from placement new, or people wanting placement new to return the
same pointer.  I believe that the latter is more common.  At least, I've
heard from some such people, whereas I have heard from nobody in the former
category.

Matt:  Why not just say

  padding = max (sizeof (size_t), alignof (T))

?  I don't see any reason to mention long double by name, and I don't
see much of a reason to treat char specially, either.  Are there any
alignment constraints on 'new char' in the standard?

Jason