[moefh]

Assuming OP was talking about overloading the '=' operator:

  struct A {
    int *p = nullptr;
  
    A& operator=(int i) {
      *p = i;
      return *this;
    }
  };

  int main(void)
  {
    A a;
    a = 1;  /* boom! */
    return 0;
  }