C++ Primer Plus

Classes Whose Constructors Use new

You need to take several precautions when designing classes that use the new operator to allocate memory pointed to by a class member (yes, we summarized these precautions recently, but the rules are very important to remember, particularly because the compiler does not know them and thus won’t catch your mistakes):

• Any class member that points to memory allocated by new should have the delete operator applied to it in the class destructor. This frees the allocated memory.

• If a destructor frees memory by applying delete to a pointer that is a class member, every constructor for that class should initialize that pointer, either by using new or by setting the pointer to the null pointer.

• Constructors should ...