Copy elision seems to occur even if compiling with -fno-elide-constructors

Question

#include <iostream>

class A {
public:
    A() { std::cout << "Constructor" << std::endl; }
    A(const A& a) { std::cout << "Copy Constructor" << std::endl; }
    A& operator=(const A& a) { std::cout << "Copy = operator" << std::endl; }
    A(A&& a) { std::cout << "Move Constructor" << std::endl; }
    A& operator=(A&& a) { std::cout << "Move = operator" << std::endl; }
    ~A() { std::cout << "Destructor" << std::endl; }
};

void f(A&& a) { std::cout << "function" << std::endl; }

int main() {
    f(A());
    return 0;
}

The output of the following program is:

Constructor
function
Destructor

Why is the move-constructor not called here? It seems like copy elision occurs even if I compile with the flag -fno-elide-constructors: g++ test.cpp -fno-elide-constructors -std=c++11

Answer 1

Short answer: You are not move-constructing anything.

You are just creating a temporary Aobject and then passing a reference to it. If you want to see move construction, you could e.g. change the signature of f to

void f(A a)