Class members that are objects - Pointers or not? C++

Question

If I create a class MyClass and it has some private member say MyOtherClass, is it better to make MyOtherClass a pointer or not? What does it mean also to have it as not a

Answer 1

Some advantages of pointer member:

• The child (MyOtherClass) object can have different lifetime than its parent (MyClass).
• The object can possibly be shared between several MyClass (or other) objects.
• When compiling the header file for MyClass, the compiler doesn't necessarily have to know the definition of MyOtherClass. You don't have to include its header, thus decreasing compile times.
• Makes MyClass size smaller. This can be important for performance if your code does a lot of copying of MyClass objects. You can just copy the MyOtherClass pointer and implement some kind of reference counting system.

Advantages of having the member as an object:

• You don't have to explicitely write code to create and destroy the object. It's easier and and less error-prone.
• Makes memory management more efficient because only one block of memory needs to be allocated instead of two.
• Implementing assignment operators, copy/move constructors etc is much simpler.
• More intuitive