time - Comparison of Duration/Seconds in C++ using chrono doesnt work as supposed? -


edit: works fine, messed in place of code.

i trying increase integer once every minute, using c++11 chrono library. reasons, comparison not work should: returns true every time. wrong cast seconds? shouldn't result int, containing difference of both time points in seconds?

would appreciate help! here's code:

std::chrono::time_point<std::chrono::system_clock> starttime = std::chrono::system_clock::now();  int timeline = 0;  int main() {     while (true) {         std::chrono::time_point<std::chrono::system_clock> = std::chrono::system_clock::now();          int seconds = timeline * 60;          if ((std::chrono::duration_cast<std::chrono::seconds>(starttime - now)).count() + seconds <= 0) {             timeline++;             nextconstellation();             cout << "timeline: " << timeline << endl;          }     } }

here safer, , more readable way write code:

std::chrono::time_point<std::chrono::system_clock> starttime = std::chrono::system_clock::now();  int timeline = 0;  int main() {     while (true) {         std::chrono::time_point<std::chrono::system_clock> = std::chrono::system_clock::now();          std::chrono::seconds seconds = timeline * std::chrono::minutes{1};          if (starttime - + seconds <= std::chrono::seconds{0}) {             timeline++;             nextconstellation();             std::cout << "timeline: " << timeline << std::endl;          }     } }

in nutshell, stay within chrono-type system, , trust units conversions you, implicitly wherever possible.

or perhaps more simply:

    // ...     auto timelimit = timeline * std::chrono::minutes{1};      if (now  - starttime >= timelimit) {     // ...

and if in c++14, add using namespace std::chrono_literals and:

    auto timelimit = timeline * 1min;

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