Chrono.cpp

//Chrono.cpp
#include "Chrono.h"

namespace Chrono {
	//member function definitions;

	Date::Date(int yy, Month mm, int dd)
		:y{yy}, m{mm}, d{dd}
	{
		if(!is_date(yy,mm,dd) throw Invalid{};
	}
	
	const Date& default_date()
	{
		static Date dd{2001, Month::jan, 1}; //start of 21st century
		return dd;
	}

	Date::Date()
		:y{default_date().year()},
		m{default_date().month()},
		d{default_date().day()}
	{
	}


	void Date::add_day(int n)
	{
		//...
	}
	
	void Date::add_month(int n)
	{
		//...
	}

	void Date::add_year(int n)
	{
		if(m==Month::feb && d==29 && !leapyear(y+n)){
			m=Month::mar;
			d=1;
		}
		y+=n;
	}
	//helper functions

	bool is_date(int y, Month m, int d)
	{
		//assume that y is valid
		
		if(d<=0) return false;
		if(m<Month::jan || Month::dec < m) return false;

		int days_in_month = 31;
	
		switch (m){
			case Month::feb:
				days_in_month = (leapyear(y)?29:28; //any traspás 29, sinó 28
				break;
			case Month::apr: case Month::jun: case Month::sep: case Month::nov:
º				days_in_month = 30; 	//the rest have 30 days
				break;
		}
		
		if(days_in_month < d) return false;
		
		return true;
	}
	bool leapyear(int y)
	{
		//see exercise 10
	}

	bool operator==(const Date& a, const Date& b)
	{
		return a.year()==b.year()
			&& a.month() == b.month()
			&& a.day() == b.day();
	}

	bool operator!=(const Date& a, const Date& b)
	{
		return !(a==b);
	}

	ostream& operator<<(ostream& os, const Date& d)
	{
		return os << '(' << d.year()
			<< ',' << d.month()
			<< ',' << d.day() << ')';
	}
	
	istream& operator>>(istream& is, Date& dd)
	{
		int y, m, d;
		char ch1, ch2, ch3, ch4;
		is >> ch1 >> y >> ch2 >> m >> ch3 >> d >> ch4;
		if(!is) return is;
		if(ch1!='(' || ch2!=',' || ch3!=',' || ch4!=')'){	//format error
			is.clear(ios_base::failbit);
		return is;
		}
		dd = Date(y, Month(m), d);
		
		return is;
	}
	enum class Day{
		sunday, monday, tuesday, wednesday, thursday, friday, saturday
	};
	
	Day day_of_week(const Date& d)
	{
		//...
	}
	Date next_Sunday(const Date& d)
	{
		//...
	}
	Date next_weekday(const Date& d)
	{
		//...
	}
}//Chrono