This is only a problem when an object construct throws an exception, and it is described in C ++ 11 5.3.4 / 18:
If the unambiguous function of maladjustment of the correspondence cannot be found, the propagating exception does not free up the memory of objects. [Note: this is suitable when the called distribution function does not allocate memory; otherwise it will most likely lead to memory leak. -end note]
Example:
T * p = new (true, 'x', Blue) T("Jim");
If the T constructor throws, we need an operator delete(void *, bool, char, enum Color) overload operator delete(void *, bool, char, enum Color) , either in the namespace area or as a static member of T , and if this function does not exist, then the release function is not called.
As noted in the note, in the case of posting-new features that are essentially no-ops, this may not be a problem. However, if the distribution function does nontrivial work, then there will be no corresponding cleaning function.