constructors/move/prog.cc - Use of constructors - with local variables of class type. | Lecture 4 - slide 10 : 40 Program 3 |
//Point(): (0,7) Point(double x): (x, 20) Point(double x, double y): (x, y) //Point(Point& p) (p.x+1, p.y+2) Point(Point&& p) (p.x-3, p.y-4) //Reveal... #include <iostream> #include "point.h" using namespace std; //A Point identity function - revealing the parameter p by printing on standard output. Point pf(Point p){ cout << "Inside pf: Parameter: " << p << endl; return p; } int f(){ Point p; cout << "Point p: " << p << endl; // (0,7) Point q = pf(p); // Passing p to pf via copy constructor: (1,9) cout << "Point q: " << q << endl; // (-2,5) - because pf handles return via the move constructor. Point r = pf(Point{10,12}); // Constructing point (10,12) via Point(double,double). Passing it bitwise!? cout << "Point r: " << r << endl; // (7,8). Returning via use of move constructor. Point s = pf(move(Point{10,12})); // Passing Rvalue point (10, 12) to pf via forced used of move constructor (7,8). cout << "Point s: " << s << endl; // (4,4) - because pf handles return via the move constructor. } int main(){ f(); }