I appreciate it's just an example, but it should be mentioned that this is a really bad class. If you write a custom destructor, you must also specify the move/

I appreciate it's just an example, but it should be mentioned that this is a really bad class. If you write a custom destructor, you must also specify the move/copy constructors and move/assignment operators. Otherwise, the same data pointer will be deleted twice if the object is ever copied.