Adhering to the rules of three and five

There's one more thing to mention when discussing special member functions: if you don't delete them and are providing your own implementations, most probably you need to define all of them, including the destructor, too. This was called the rule of three in C++98 (due to the need to define three functions: the copy constructor, the copy assignment operator, and the destructor) and since C++11's move operations, it is now replaced by the rule of five (the two additional ones being the move constructor and the move assignment operator). Applying these rules can help you avoid resource management issues.