#include <iostream>

using namespace std;

class A
{
public:
    A() { }
    void operator+(int)
    {
        cout << "+" << endl;
    }
};

void operator-(A &&, int)
{
    cout << "-" << endl;
}

int main()
{
    A() + 1;
    A() - 1;
    return 0;
}

Line 15: error: expected ',' or '...' before '&&' token
compilation terminated due to -Wfatal-errors.