...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
#include "boost/date_time/gregorian/gregorian.hpp" #include "boost/date_time/date_parsing.hpp" #include <iostream> int main() { using namespace boost::gregorian; std::string s; std::cout << "Enter birth day YYYY-MM-DD (eg: 2002-02-01): "; std::cin >> s; try { date birthday(boost::date_time::parse_date<date>(s)); //date birthday(2002,Jan,1); date today = day_clock::local_day(); date_duration days_alive = today - birthday; date_duration one_day(1); if (days_alive == one_day) { std::cout << "Born yesterday, very funny" << std::endl; } else if (days_alive < date_duration(0)) { std::cout << "Not born yet, hmm: " << days_alive.days() << " days" <<std::endl; } else { std::cout << "Days alive: " << days_alive.days() << std::endl; } } catch(...) { std::cout << "Bad date entered: " << s << std::endl; } return 0; };