#include<iostream>
#include<future>
#include <thread>
/*********furture 和promi***************************/
int display(const int& value) {
return 10 + value;
}
//不能傳引用,是簡單的值拷貝
int display1(std::shared_future<int> f) {
//地方會一直等待,阻塞狀態,由其它線程傳入值
int value = f.get();
return value;
}
//不能傳引用,是簡單的值拷貝
int display2(std::shared_future<int> f) {
//地方會一直等待,阻塞狀態,由其它線程傳入值
int value = f.get();
return value;
}
int main()
{
std::cout << "11" << std::endl;
int value = 10;
//取決運行環境
std::future<int>fu = std::async(std::launch::async | std::launch::deferred, display, std::ref(value));
int value1 = fu.get();
std::cout << value1 << std::endl;
//定義一個promise的變量
std::promise<int>promise;
//傳遞下一個線程
promise.set_value(10);
//std::future<int> fu11 = promise.get_future();
//共享furture,所有線程都可以用
std::future<int>fu11 = promise.get_future();
std::shared_future<int>shared_futrue = fu11.share();
//std::launch::async create thread
//std::launch::deferred
std::future<int>fu1 = std::async(std::launch::async | std::launch::deferred, display1, shared_futrue);
std::future<int>fu2 = std::async(std::launch::async | std::launch::deferred, display2, shared_futrue);
int value11 = fu1.get();
int value22 = fu2.get();
//std::thread t(display1, std::ref(fu11));
}