add new member to copy c-tor/copy o-tor/serialization reminder

Question

Almost all c++ projects have classes with copy c-tor/copy operator/serialize method etc. Which usualy doing something with all members.

But sometimes developers forg

Answer 1

template
class SafeMember {
public:
    T _;    /* short name for convenience */
    SafeMember(T const& obj) : _(obj) { }
};

Used like this:

class Student {
public:
    Student(string surname, Color hairColor)
        : surname(surname)
        , hairColor(hairColor) { }

    Student(Student const& other)
        : surname(other.surname)
        , hairColor(other.hairColor) { }

    Student& operator=(Student const& other) {
        surname = other.surname;
        hairColor = other.hairColor;
        return *this;
    }

    string getSurname() const { return surname._; }

    // The foo._ syntax is better than implicit conversion because
    // it lets us call member functions, like substr in this example:
    bool isSlavic() const {return surname._.substr(surname._.size()-2)=="ev";}

    void dyeHair(Color newColor) { hairColor = newColor; }

private:
    SafeMember surname;
    SafeMember hairColor;
};

Now when you add a "SafeMember age" member and forget to update your copy-constructor, the compilation will helpfully fail.

And for a "no-op" hint, the developer would add an initializer like ":age(0)".

Note: this doesn't protect your operator=() or serialize() functions from bit-rot, only the constructors. Hopefully, though, this should be enough: once you see your omission from the constructors, you will probably remember to go through the other functions as well.