[cpp] c++11 member function thread test

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

class threadClass{
public:
  void run(int num){
    while(num>0){
      auto tt = std::make_shared<std::thread>(&threadClass::test,this);
      threads_.push_back(tt);
      --num;
    }
    for(auto tt:threads_){
      tt->join();
    }
    threads_.clear();
  }
private:
  void test(){
    int val = val_++;
    val_lock_.lock();
    std::cout << val << std::endl;
    val_lock_.unlock();
  }

private:
  std::atomic<int> val_{0};
  std::vector<std::shared_ptr<std::thread> > threads_;
  std::mutex val_lock_;
};

int main()
{
  threadClass tt;
  tt.run(10);
  tt.run(10);
  return 0;
}