C++:来自 std::thread 的简单返回值?

With win32 threads I have the straight forward GetExitCodeThread() that gives me the value which the thread function returned. I'm looking for something similar for std::thread (or boost threads)
As I understand this can be done with futures but how exactly?

推荐答案

参见 关于 C++11 期货的视频教程.

明确使用线程和期货:

#include <thread>
#include <future>

void func(std::promise<int> && p) {
    p.set_value(1);
}

std::promise<int> p;
auto f = p.get_future();
std::thread t(&func, std::move(p));
t.join();
int i = f.get();

或者使用 std::async(线程和期货的高级包装器):

#include <thread>
#include <future>
int func() { return 1; }
std::future<int> ret = std::async(&func);
int i = ret.get();