...
It is acceptable to define a deleted or nonpublic private allocation or deallocation function without its corresponding free store function. For instance, it is a common practice to define a deleted non-placement allocation or deallocation function as a class member function when the class also defines a placement new function. This prevents accidental allocation via calls to new for that class type, or deallocation via calls to delete on pointers to an object of that class type.
...