Future get() returns void for int returning member function

#include <functional>
#include <future>
#include <iostream>

class A
{
    public:
    int run(int a, const std::string& s)
    {
        std::cout << "a=" << a << ",s=" << s << std::endl;
        return a+1;
    }
};

int main()
{
    A a;
    auto f = std::bind(&A::run,&a,5,std::placeholders::_1);
    std::packaged_task<int(const std::string&)> pt(std::move(f));

    auto fut = std::async(std::move(pt),"test");
    /// std::cout << fut.get() << std::endl; Does not compile
    fut.get();
    return 0;
}

Why fut.get() is returning void ? A::run is defined to return int and hence it should return int instead of void.