Cannot use protected constructor in a derived class

Question

I need to set the 3 values in the House class which is derived from Dwelling class but it gives me the error that cannot call protected constructor

class Dwelling {
    int bedrooms;
protected:
    Dwelling(){bedrooms=0;};
    Dwelling(int _b){bedrooms=_b;};
};

class House : public Dwelling {
    int storeys;
    bool garden;
public:
    House() {storeys=0; garden=0;};
    //constructor to set storeys, garden and bedrooms.
        House(int st, bool val, int room){
        if (st >= 1 || st <= 4) {
            storeys = st;
            garden = val;
            Dwelling(room); // Gives me ERROR here
        }
    }
};

int main(){
    House a(2, true, 3);
}

That does not work, and it's not because of the base constructor being protected. See for example [C++ explicitly call parent constructor outside initialization list](https://stackoverflow.com/questions/47245092/c-explicitly-call-parent-constructor-outside-initialization-list). — dxiv, Aug 12 '20 at 03:01

score 1 · Accepted Answer · answered Aug 12 '20 at 03:00

The error has nothing to do with calling the protected constructor, because this line:

Dwelling(room);

is not a call to the base class constructor at all. It's just a declaration of a variable named room of type Dwelling with a pair of redundant parentheses around the declarator. (c++ syntax can be strange sometimes, and you need to read the error messages closely to figure out what's going on).

To actually call the base class constructor, use a member-initializer-list like this:

House(int st, bool val, int room) : Dwelling(room) {

Cannot use protected constructor in a derived class

1 Answers1