How to get a return value from a thread?

Lets say a function,

    int fun(){
        static int a = 10;
        a = a+1;
        return a;
    }

The above function is returning a integer value,

    //Without thread obtaining return value
    #include<iostream>
    int main()
    {
        int var = 0;
        var = fun();
        std::cout << "The value " << value << std::endl;
        return 0;
    }

Now is there any possible way to get the returned value when invoked by C++11 thread,

    //Using thread
    #include<iostream>
    #include<thread>
    int main()
    {
        std::thread t1(fun);//Invoking thread
        //How to obtain the return value of the thread ?
        return 0;
    }

Thanks!