#include <chrono>

auto now = std::chrono::system_clock::now();

auto duration = std::chrono::seconds(5);

auto future_time = now + duration;

#include <iostream>
#include <chrono>

void someFunction() {
    // 模拟一些操作
    std::this_thread::sleep_for(std::chrono::seconds(1));
}

int main() {
    auto start = std::chrono::high_resolution_clock::now();

    someFunction();

    auto end = std::chrono::high_resolution_clock::now();

    auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
    std::cout << "Function took " << duration.count() << " milliseconds to execute." << std::endl;

    return 0;
}

Function took 1000 milliseconds to execute.

#include <iostream>
#include <chrono>
#include <ctime>

int main() {
    auto now = std::chrono::system_clock::now();
    std::time_t now_c = std::chrono::system_clock::to_time_t(now);
    std::cout << "Current date and time: " << std::ctime(&now_c);

    return 0;
}

Current date and time: Fri Mar 11 12:34:56 2022

#include <iostream>
#include <iomanip>
#include <chrono>
#include <ctime>

int main() {
    auto now = std::chrono::system_clock::now();
    std::time_t now_c = std::chrono::system_clock::to_time_t(now);

    std::cout << std::put_time(std::localtime(&now_c), "%Y-%m-%d %H:%M:%S");

    return 0;
}

2022-03-11 12:34:56