C++ Primer Plus

Delegating Constructors

If you provide a class with several constructors, you may find yourself writing the same code over and over. That is, some of the constructors may require you to duplicate code already present in other constructors. To make coding simpler and more reliable, C++11 allows to you use a constructor as part of the definition of another constructor. This process is termed delegation because one constructor temporarily delegates responsibility to another constructor to work on the object it is constructing. Delegation uses a variant of the member initialization list syntax:

class Notes {    int k;    double x;    std::string st;public:    Notes();    Notes(int);    Notes(int, double);    Notes(int, double, std::string);};Notes::Notes(int ...