How to prevent the creation of an object in C-CodePudding

i'm learning how to make classes and i want to prevent my user from creating an object without providing a variable. The problem is that i don't know how to procede in order to do that. here's my code :

class KoalaNurse {
    public:
        int id; // the var that i need to provide in order to create a new object if it's not provided it wont create the object
        void giveDrug(std::string gato, SickKoala *patient) {
            patient->takeDrug(gato);
        }
        ~KoalaNurse() {
            std::cout << "Nurse " << id << ": Finally some rest !" << std::endl;
        }
};

ty for any help !

CodePudding user response：

You need to define your own constructor in order for the compiler not to create the default one.

KoalaNurse (int some_value)
{
 //your code
};

Another option is to use keyword delete in order to prevent creating default constructor:

KoalaNurse() = delete;

CodePudding user response：

In a situation like this you want to provide a user defined constructor.

class KoalaNurse {
public:
    explicit KoalaNurse( int id )
        : id_{ id }
    { }

private:
    int id_;
};

int main( ) {
    KoalaNurse nurse{ 10 };
}

With a constructor, in order to instantiate your class you have to provide an id.