c++ - 测量剩余使用时间

Question

我想制作一个函数，引用上次函数被调用的时间，以确保最多只能每 10 秒调用一次:

void SetUseFunctionLastTime()
    {
        std::chrono::system_clock::now();
    }

        bool UseFunction()
        {
            if (/*Code here*/) /*HERE: I want to check the remaining time 
                               left before I can call it again*/
            {
                Log("Wait %d seconds to use this", seconds_left)
                return false;
            }

        SetUseFunctionLastTime()
    }

你是如何做到这一点的？

Answer 1

#include <chrono>

bool UseFunction() {
    constexpr std::chrono::duration<double> interval_seconds{ 10.0 };
    static std::chrono::time_point<std::chrono::steady_clock> last_call{ std::chrono::steady_clock::now() };
    const auto now = std::chrono::steady_clock::now();
    const auto elapsed_time = std::chrono::duration_cast<std::chrono::seconds>(now - last_call);
    const auto seconds_left = std::chrono::duration_cast<std::chrono::seconds>(interval_seconds - elapsed_time).count();
    if (seconds_left > 0) {
        printf("Wait %lld seconds to use this\n", seconds_left);
        return false;
    }
    else {
        last_call = now;
        printf("Returning true.\n");
        return true;
    }
}