Joy of c++

#include <type_traits>

decltype(auto) foo1() {
    int x;
    return x;
}

decltype(auto) foo2() {
    int x;
    return (x);
}

int main() {
    static_assert(std::is_same<decltype(foo1()),int>::value, "");
    static_assert(std::is_same<decltype(foo2()),int&>::value, "");
}