Missing related operator definition

A class defines an operator but lacks a definition for a naturally related operator.

This error flags several kinds of irregular usage that makes a class awkward to use. For example, a class that defines an operator such as "greater than" should also provide a definition for a related operator such as "less than". While it is true that a user can always replace "x less than y" with "y greater than x", it is better to define a complete set of related operators. Similarly, a class that supports "+" and assignment ("=") should also support "+=".

This error is also emitted when a class defines its own "new" operator but does not also define its own "delete" or "new []" operator.

ID	Code Location	Description
1	Definition	The place where the class was defined

Example

          
#include <new>
class A
{
public:
    void *
    operator new(size_t size, void * allocator)
    throw() {
        return NULL;
    }
};

int main(int argc, char **argv)
{
    A *a = new (0) A();
    return 0;
}