cannot_understand_rtval.cpp

#include <iostream>
#include <string>

using namespace std;

class person {
private:
  int age;
  string name;
public:
  person() : age(0), name("") {};
  person(int a, string s) : age(a), name(s) {};

  person(const person& p) : age(p.age), name(p.name) {
    cout << "// copy constructor passed." << endl;
  };
  person& operator=(person& pp) {
    cout << "// copy assignment passed." << endl;
    age = pp.age;
    name = pp.name;
    return *this;
  }

  person(person&& p) : age(p.age), name(p.name) {
    cout << "// move constructor passed." << endl;
  };
  person& operator=(person&& pp) {
    cout << "// move assignment passed." << endl;
    age = pp.age;
    name = pp.name;
    return *this;
  }

  ~person() {};
  void introduce() { cout << "My name is " << name << endl; }
};

int main() {
  // simple use
  cout << "####### p" << endl;
  person p(53, "taro");
  p.introduce();

  // use copy constructor
  cout << "####### p2" << endl;
  person p2 = p;
  p2.introduce();

  // use copy assignment
  cout << "####### p3" << endl;
  person p3;
  p3 = p;
  p3.introduce();

  // use move constructor
  cout << "####### p4" << endl;
  person p4(move(p));
  p4.introduce();

  // use move assignment
  cout << "####### p5" << endl;
  person p5;
  p5 = move(p);
  p5.introduce();

  return 0;
}

imiwakaran