modern-cpp-tutorial/code/7/7.8.relaxed.cpp

#include <atomic>
#include <thread>
#include <vector>
#include <iostream>

std::atomic<int> counter = {0};

int main() {
    std::vector<std::thread> vt;
    for (int i = 0; i < 100; ++i) {
        vt.emplace_back([](){
            counter.fetch_add(1, std::memory_order_relaxed);
        });
    }

    for (auto& t : vt) {
        t.join();
    }
    std::cout << "current counter:" << counter << std::endl;
    return 0;
}