#include <cassert>
#include <chrono>
#include <ratio>
int main() {
    using namespace std::chrono;
    const milliseconds budget(1500);
    const seconds whole = duration_cast<seconds>(budget);
    const milliseconds remainder = budget - whole;
    assert(whole.count() == 1);
    assert(remainder.count() == 500);
    assert(duration_cast<seconds>(milliseconds(-1500)).count() == -1);
    const seconds wrong(budget.count());
    assert(wrong != budget);
    const duration<double> precise = budget;
    assert(precise.count() == 1.5);
    using Tick = duration<int, std::ratio<1, 4>>;
    assert(duration_cast<milliseconds>(Tick(3)).count() == 750);
    assert(whole + remainder == budget);
}