test_openmp.cpp

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

using namespace std;

void sleep(int num) {
    std::this_thread::sleep_for(std::chrono::seconds(3));
}

int main() {

#ifdef _OPENMP
#pragma omp parallel for
    for (int i = 0; i < 10; ++i) {
        printf("%d\n", i);
        sleep(i);
    }
#else
    cout << "OpenMP is not used" << endl;
#endif
    return 0;
}

clang-omp++ test_openmp.cpp -o test_openmp