C++ move constructor not called [duplicate] - c++

Question

This question already has answers here:
Why do I have to call move on an rvalue reference?
(2 answers)
Rvalue Reference is Treated as an Lvalue?
(4 answers)
Closed 5 years ago.
In the following (borrowed) example, in my environment the move constructor is never called:
#include <iostream>
class MyClass {
public:
MyClass()
{
std::cout << "default constructor\n";
}
MyClass(MyClass& a)
{
std::cout << "copy constructor\n";
}
MyClass(MyClass&& b)
{
std::cout << "move constructor\n";
}
};
void test(MyClass&& temp)
{
MyClass a(MyClass{}); // calls MOVE constructor as expected
MyClass b(temp); // calls COPY constructor...
}
int main()
{
test(MyClass{});
return 0;
}
My output is:
default constructor
default constructor
copy constructor
I use XCode version 9.1, shouldnt the move constructor be called on rvalue references? What am I missing here?
John.

Answer 1

What am I missing here?
The point is that everything that has a name is lvalue.
It means that named rvalue reference itself is lvalue and temp from:
void test(MyClass&& temp)
is lvalue as well. So move constructor is not called.
If you want a move constructor to be called, use std::move:
void test(MyClass&& temp)
{
// ...
MyClass b(std::move(temp)); // use std::move here
}
By the way,
MyClass(MyClass& a)
{
std::cout << "copy constructor\n";
}
is not a copy constructor because copy constructor has a form of:
MyClass(const MyClass& a) { ... }