Question

class Temp {
    public : 
        Temp(X& x): x_(x) {}
        Temp(X& x, Y& y) : x_(x), y_(y) {}
        ...
    private:
        X& x_;
        Y& y_;
}

I got the error because in case of Temp(X& x): x_(x) the reference y_ is not initialized. What is the common practice to write such a class correctly ?

Answer 1

I will suggest another approach, even though that may be not what you are looking for.

It doesn’t use reference variables (memory pointers instead), it also doesn’t use boost, but it will allow you to keep both constructors without spending any more memory resources.

#include <iostream>

class Temp
{
    public :
        Temp(int& x): x_(&x), y_(NULL) {}
        Temp(int& x, int& y) : x_(&x), y_(&y) {}
        void print() { std::cout << "*x_: " << *x_ << std::endl; }

    private:
        int* x_;
        int* y_;
};

int main()
{
    int x = 5;
    Temp tmp(x);

    tmp.print();

    return 0;
}