On 09/04/2014 07:11 PM, Jonathan Wakely wrote:
Placement new might work with GCC in practice as long as the buffer is correctly aligned and the type being constructed does not have non-trivial initialization. However, my reading of the standard is that after the placement new, if the object's members are not initialized then they have indeterminate values (not the values that were at those memory addresses already, even though that's likely to be what happens in practice).
I think that's a defect in the (non-normative) note in 5.3.4/17, which is assuming that this follows from the rule in 8.5/12. But I don't think it does, because in this case the storage has been initialized and therefore is no longer indeterminate.
So I think the placement new form is OK. Jason
