#include <unistd.h>
#include <iostream>
#include <thread>

int main(void) {
    std::cout << "Before thread" << std::endl;
    std::thread t([]() {
        sleep(1);
        std::cout << "In a thread." << std::endl;
    });
    t.join();
    std::cout << "After thread" << std::endl;
}