Advantage of using auto in function return value using C++11

What is the advantage of using auto in function return type definition in C++11? ( foo2() vs foo1() )

int foo1(){
    // ...
    return 1;    
}

auto foo2() ->int {
    // ...
    return 1;    
}

int main()
{
    foo1();
    foo2();
    return 0;
}