In C++11 a constructor may call another constructor of the same class:
class M //C++11 delegating constructors
{
int x, y;
char *p;
public:
M(int v) : x(v), y(0), p(new char [MAX]) {} //#1 target
M(): M(0) {cout<<"delegating ctor"<<endl;} //#2 delegating
};
Constructor #2, the delegating constructor, invokes the target constructor #1.