Questions / Quant development, C++ ownership & memory
A named rvalue reference is an lvalue expression
C++17. Which overload code does relay(5) return? The overloads and relay template are shown.
int pick(int&) { return 1; }
int pick(int&&) { return 2; }
template<class T> int relay(T&& x) { return pick(x); }
// In main:
std::cout << relay(5);Answer it in the app It's free. You get hints, a second try if you miss, and a follow-up question.
Show the answer and worked solution
Answer: 1 overload code
- Although x has an rvalue-reference type in this instantiation, the expression x is an lvalue. Passing it directly therefore selects pick(int&) and returns 1.
Interview shortcut. A named rvalue reference is an lvalue.
In the app this has a follow-up where one thing about the setup changes. Try the follow-up.