Wie schreibe ich die Kopie Konstruktor für Komposition?

Question

unter mein Code:

class Pulley{ 
private: 
    int noOfTeeth; 

public: 
    Pulley(); 
    Pulley(int teeth); 
    ~Pulley(); 

    void show(); 
}; 

Pulley::Pulley() 
{ 
    cout << "Pulley constructor called!"; 
    noOfTeeth = 0; 
} 

Pulley::Pulley(int teeth) 
{ 
    cout << "Pulley constructor called!"; 
    noOfTeeth = teeth; 
} 

void Pulley::show() 
{ 
    cout << "\n\nNo of Teeths of Pulley: " << noOfTeeth; 
} 

Pulley::~Pulley() 
{ 

} 

class GearBox{ 
    private: 
    char *transmission; 
    Pulley p; 

    public: 
    GearBox(); 
    GearBox(char *trans, int pTeeth); 
    ~GearBox(); 

    void show(); 
}; 

GearBox::GearBox(): p() 
{ 
    cout << "Gearbox constructor called!"; 
    transmission = NULL; 
} 

GearBox::GearBox(char *trans, int pTeeth): p(pTeeth) 
{ 
    cout << "Gearbox constructor called!"; 
    if(trans != NULL) 
    { 
     transmission = new char[strlen(trans)+1]; 
     strcpy(transmission, trans); 
    } 
    else 
    { 
     transmission = NULL; 
    } 
} 

void GearBox::show() 
{ 
    cout << "\n\nTransmission of vehicle: " << transmission; 
    p.show(); 
} 

GearBox::~GearBox() 
{ 

} 

class Vehicle{ 
private: 
    char *model; 
    char *color; 
    GearBox g; 

public: 
    Vehicle(); 
    Vehicle(char *mod, char *col, char *gr); 
    Vehicle(const Vehicle &vh); 
    ~Vehicle(); 

    void show(); 
}; 

Vehicle::Vehicle(): g() 
{ 
    cout << "Vehicle constructor called!"; 
    model = NULL; 
    color = NULL; 
} 

Vehicle::Vehicle(char *mod, char *col, char *gr): g(gr) 
{ 
    cout << "Vehicle constructor called!"; 
    if(mod != NULL) 
    { 
     model = new char[strlen(mod)+1]; 
     strcpy(model, mod); 
    } 
    else 
    { 
     model = NULL; 
    } 

    if(col != NULL) 
    { 
     color = new char[strlen(col)+1]; 
     strcpy(color, col); 
    } 
    else 
    { 
     color = NULL; 
    } 
} 

void Vehicle::show() 
{ 
    cout << "\n\nModel of Vehicle: " << model; 
    cout << "\n\nColor of Vehicle: " << color; 
    g.show(); 
} 

int main() 
{ 
    Pulley p(20); 
    GearBox g("Manual", p); 
    Vehicle V("Honda", "Black", g); 
    V.show(); 
    system("PAUSE"); 
} 

Nun, wenn ich diesen Code ausführen bekomme ich eine Menge Fehler, ich weiß nicht, was sind die, und wie sie zu lösen. Der einzige Fehler, den ich verstanden habe, ist von Copy Constructor, also kann mir jemand erklären, wie ich den Kopierkonstruktor für Zeiger auf Zeichen transmission, model and color schreiben kann. Sagen Sie mir auch, wie ich andere Fehler beheben kann. Danke vielmals.

Answer 1

Versuchen wie folgt aus:

#include <string> 
#include <iostream> 

class Pulley{ 
private: 
    int noOfTeeth; 

public: 
    Pulley(int teeth = 0); 

    void show(); 
}; 

Pulley::Pulley(int teeth) 
: noOfTeeth(teeth) 
{ 
    std::cout << "Pulley constructor called!"; 
} 

void Pulley::show() 
{ 
    std::cout << "\n\nNo of Teeths of Pulley: " << noOfTeeth; 
} 

class GearBox{ 
    private: 
    std::string transmission; 
    Pulley p; 

    public: 
    GearBox(std::string trans = std::string(), Pulley p = Pulley()); 

    void show(); 
}; 

GearBox::GearBox(std::string trans, Pulley p) 
: transmission(std::move(trans)) 
, p(std::move(p)) 
{ 
    std::cout << "Gearbox constructor called!"; 
} 

void GearBox::show() 
{ 
    std::cout << "\n\nTransmission of vehicle: " << transmission; 
    p.show(); 
} 

class Vehicle{ 
private: 
    std::string model; 
    std::string color; 
    GearBox g; 

public: 
    Vehicle(); 
    Vehicle(std::string mod = "", std::string col = "", GearBox gr = GearBox()); 

    void show(); 
}; 

Vehicle::Vehicle(std::string mod,std::string col, GearBox gr) 
: model(std::move(mod)) 
, color(std::move(col)) 
, g(std::move(gr)) 
{ 
    std::cout << "Vehicle constructor called!"; 
} 

void Vehicle::show() 
{ 
    std::cout << "\n\nModel of Vehicle: " << model; 
    std::cout << "\n\nColor of Vehicle: " << color; 
    g.show(); 
} 

int main() 
{ 
    Pulley p(20); 
    GearBox g("Manual", p); 
    Vehicle V("Honda", "Black", g); 
    V.show(); 
// system("PAUSE"); 
}