unique_ptr.cpp

#include <iostream>
#include <memory>

class MyTime
{
    int hours;
    int minutes;
  public:
    MyTime(): hours(0), minutes(0)
    {
        std::cout << "Constructor MyTime()" << std::endl;
    }
    MyTime(int m): hours(0), minutes(m)
    {
        std::cout << "Constructor MyTime(int)" << std::endl;
        this->hours +=  this->minutes / 60;
        this->minutes %= 60;
    }
    MyTime(int h, int m): hours(h), minutes(m)
    {
        std::cout << "Constructor MyTime(int,int)" << std::endl;
        this->hours +=  this->minutes / 60;
        this->minutes %= 60;
    }
    ~MyTime()
    {
        std::cout << "Destructor MyTime(). Bye!" << std::endl;
    }
    MyTime operator+(int m) const
    {
        MyTime sum;
        sum.minutes = this->minutes + m;
        sum.hours = this->hours;
        sum.hours +=  sum.minutes / 60;
        sum.minutes %= 60;
        return sum;
    }
    friend std::ostream & operator<<(std::ostream & os, const MyTime & t)
    {
        std::string str = std::to_string(t.hours) + " hours and " 
                        + std::to_string(t.minutes) + " minutes.";
        os << str;
        return os;
    }
};


int main()
{
    std::unique_ptr<MyTime> mt1(new MyTime(10));
    std::unique_ptr<MyTime> mt2 = std::make_unique<MyTime>(80); //c++17

    std::cout << "mt1: " <<*mt1 << std::endl;
    std::cout << "mt2: " <<*mt2 << std::endl;

    // std::unique_ptr<MyTime> mt3 = mt1; // error
    std::unique_ptr<MyTime> mt3 = std::move(mt1); 
    // std::shared_ptr<MyTime> mt3 = std::move(mt1);//okay
    
    // std::cout << "mt1: " <<*mt1 << std::endl;
    std::cout << "mt3: " <<*mt3 << std::endl;

    return 0;
}