Given this forwarding wrapper, what does the call print?
#include <iostream>
#include <utility>
void sink(int& x) { std::cout << "lvalue\n"; }
void sink(int&& x) { std::cout << "rvalue\n"; }
template <typename T>
void relay(T&& arg) {
sink(arg); // line A
sink(std::forward<T>(arg)); // line B
}
int main() {
relay(42);
}