C++Future简单的使用

#include "stdafx.h"
#include <thread>
#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <mutex>
#include <stack>
#include <string>
#include <exception>
#include <memory> // For std::shared_ptr<>
#include <queue>
#include <condition_variable>
#include <atomic>
#include <future>
using namespace std;
int Add()
{
    cout << "Future add exe!" << endl;
    return 1;
}
int Sum(int a, int b)
{
    return a + b;
}
struct MySum
{
    int Sum(int a, int b){ return a + b; }
};
int _tmain(int argc, _TCHAR* argv[])
{
    std::future<int> the_answer = std::async(std::launch::async/*std::launch::deferred*/, Add);
    // 通过延时来看期望的两个选项的差异(std::launch::async --- 异步线程执行,std::launch::deferred --- 延时执行)
    this_thread::sleep_for(chrono::seconds(10));
    std::cout << "The answer is " << the_answer.get() << std::endl;
    std::future<int> the_sum = std::async(Sum, 1, 2);
    std::cout << "The Sum is " << the_sum.get() << std::endl;
    MySum TheStructSum;
    std::future<int> StructSum = std::async(&MySum::Sum, TheStructSum, 3, 4);
    std::cout << "The Struct Sum is " << StructSum.get() << std::endl;
    return 0;
}