如何从boost线程获取返回值？

#include <boost/thread.hpp>

int calculateSum(int a, int b) {
    return a + b;
}

void threadFunction(boost::promise<int>& p, int a, int b) {
    int result = calculateSum(a, b);
    p.set_value(result);
}

int main() {
    int a = 5;
    int b = 3;

    boost::promise<int> p;
    boost::future<int> f = p.get_future();

    boost::thread t(threadFunction, boost::ref(p), a, b);

    // 等待线程执行完毕并获取结果
    int result = f.get();

    t.join();

    // 打印结果
    std::cout << "Sum: " << result << std::endl;

    return 0;
}