Understanding the various forms of non-static member initialization

Constructors are places where non-static class member initialization is done. Many developers prefer assignments in the constructor body. Aside from the several exceptional cases when that is actually necessary, initialization of non-static members should be done in the constructor's initializer list or, as of C++11, using default member initialization when they are declared in the class. Prior to C++11, constants and non-constant non-static data members of a class had to be initialized in the constructor. Initialization on declaration in a class was only possible for static constants. As we will see here, this limitation was removed in C++11, which allows the initialization of non-statics in the class declaration. This initialization is called default member initialization and is explained in the following sections.

This recipe will explore the ways non-static member initialization should be done. Using...