Hello, I can't understand what compiler wants from me. I trying to create quite a big class structure with many abstract classes. Below is a part of the code with some of them. The compiler doesn't like my classes and says the he needs more constructor which I don't understand. Shouldn't he make his own default constructors? I put the copy constructors into the private part. Maybe it doesn't make much sense but even when I delete them the compiler still has a problem. I'm posting one class with and one without the copy constuctor so that you can see how it behaves in both cases.

#include<iostream>
using namespace std;
class Okno {
protected:    
    int x1,y1,x2,y2;
    string nazwa;
public:   
    int daj_x1() {return x1;}
    int daj_y1() {return y1;}
    int daj_x2() {return x2;}
    int daj_y2() {return y2;}
};

//    subclasses of Okno
class NieDesktop : public Okno{
private:
    NieDesktop(const NieDesktop&);
protected:
    Okno& ojciec;    
public:
    NieDesktop(Okno&);      
    Okno& DajOjca();      
};

NieDesktop::NieDesktop(Okno& _ojciec) : ojciec(_ojciec){}
Okno&  NieDesktop::DajOjca(){
    return ojciec;
}
//KONTROLKA
class Kontrolka : public NieDesktop{                      //abstract
    Kontrolka(const Kontrolka&);                 
};
class KontrolkaAtomowa : public Kontrolka{                      //abstract
    KontrolkaAtomowa(const KontrolkaAtomowa&);                  
};
class KontrolkaNieatomowa : public Kontrolka{                      //abstract
    //KontrolkaNieatomowa(const KontrolkaNieatomowa&);                   
};
int main(){}

Here are the compiler's messages:

30 [Warning] ` class Kontrolka' only defines private constructors and has no friends
33 [Warning] ` class KontrolkaAtomowa' only defines private constructors and has no friends
36 `Kontrolka' with only non-default constructor in class without a constructor

When you define an overloaded constructor (such as a copy constructor), the compiler no longer provides a default constructor. You will have to explicitly define a PUBLIC default constructor.

The warnings tells a thousand words :

30 [Warning] ` class Kontrolka' only defines private constructors and has no friends 
33 [Warning] ` class KontrolkaAtomowa' only defines private constructors and has no friends 
36 `Kontrolka' with only non-default constructor in class without a constructor

Realize that in a class, if you don't specify a modifier, the function inside
of a class, the constructors, the destructures, and the member variables
are all private.

For example this class :

class Kontrolka : public NieDesktop{                      //abstract
    Kontrolka(const Kontrolka&);                 
};

The constructure you provided is private, because its that way by default. To solve your problem make the constructure pubilc, for this
one and you other ones.