promise.cpp

#include <string>
#include <iostream>
#include <future>
#include <thread>

using namespace std;

void TestFuture(promise<string> p){
    this_thread::sleep_for(3s);
    cout << "begin setting value ... " << endl;
    p.set_value("TestFuture value Hello World");
    this_thread::sleep_for(3s);
    cout <<"end Test Future ..." << endl;
}

int main(int argc, char* argv[]){

    //异步传输变量存储
    promise<string> p;

    // 用来获取线程写入值
    auto future = p.get_future();


    auto th = thread(TestFuture, std::move(p));

    cout <<"begin future get ... " << endl;
    cout << "future get(): " << future.get() << endl;


    th.join();
    return 0;
}