forward declaration of ‘struct/invalid use of incomplete type ‘struct

[bravvve]

HI
i am coding some pointer manipulation :liked list of linked list
but am getting forward declaration and invalid use of incomplete type ‘struct
i'v seen http://www.cplusplus.com/forum/articles/10627/#msg49682 but i still not get it with this code

        /*
     * neuMot.h
     *
     *  Created on: 30 avr. 2013
     *      Author: bravvve
     */
     
    #ifndef NEUCARTE_H_
    #define NEUCARTE_H_
    using namespace std;
    #include <stdlib.h>
    #include"neuCarte.h"
     
     
     
     
    class neuMot{
        public:
            neuCarte * data;
        neuMot * next;
        neuMot * previous;
     
        public:
        neuMot(neuCarte* x);
        neuMot(neuCarte* x, neuMot * n,neuMot *p);
    };
    #endif /* NEUCARTE_H_ */
     
    /*
     * neuMot.cpp
     *
     *  Created on: 30 avr. 2013
     *      Author: bravvve
     */
     
    #include "neuMot.h"
     
     
    neuMot::neuMot(neuCarte* x){
                    data = x;
                    next = NULL;
                    previous = NULL;
                    }
     
    neuMot::neuMot(neuCarte* x, neuMot * n,neuMot *p){
                    data = x;
                    next = n;
                    previous = p;
     
                    }
     
     
    /*
     * neuCarte.h
     *
     *  Created on: 30 avr. 2013
     *      Author: bravvve
     */
     
    #ifndef NEUCARTE_H_
    #define NEUCARTE_H_
    #include <stdlib.h>
     
    using namespace std;
     
     
    class neuCarte{
        public:
        char data;
        neuCarte * next;
        public:
        neuCarte(char x);
        neuCarte(char x, neuCarte * y);
    };
    #endif /* NEUCARTE_H_ */
     
    /*
     * neuCarte.cpp
     *
     *  Created on: 30 avr. 2013
     *      Author: bravvve
     */
    #include "neuCarte.h"
     
     
     
    neuCarte::neuCarte(char x){
                    data = x;
                    next = NULL;
                    }
     
    neuCarte::neuCarte(char x, neuCarte * y){
                    data = x;
                    next = y;
                    }
     
    /*
     * Centre.h
     *
     *  Created on: 29 avr. 2013
     *      Author: bravvve
     */
     
    #ifndef CENTRE_H_
    #define CENTRE_H_
     
     
     
    #include <string>
     
    using namespace std ;
    #include "neuCarte.h"
    //#include "neuMot.h"
     
    //class neuMot;
    class neuCarte;
     
    //
     
    class Centre {
    public:
            Centre(neuCarte &nc);
            void ajoutNeu();
            void CreeCentre();
            string VisualiserCentre();
     
            neuMot* tete;
            neuMot* queu;
            neuCarte& donne;
            int complet;
     
    };
     
    #endif /* CENTRE_H_ */
     
    /*
     * Centre.cpp
     *
     *  Created on: 29 avr. 2013
     *      Author: bravvve
     */
     
    #include "Centre.h"
    #include "neuCarte.h"
     
    class neuMot;     //forward declaration of ‘struct neuMot’ERROR
     
    Centre::Centre(neuCarte &nc) :
            donne(nc) {
            // TODO Auto-generated constructor stub
            tete = new neuMot(&donne);   //invalid use of incomplete type ‘struct neuMot’
            queu = tete;                 //‘queu’ was not declared in this scope
            complet = 0;
            //donne=nc;
    }
     
    void Centre::ajoutNeu() {
            neuMot* p = new neuMot(&donne);     //invalid use of incomplete type ‘struct neuMot’ ERROR
            queu->next = p;                     //‘queu’ was not declared in this scope ERROR
            p->previous = queu;                 //invalid use of incomplete type ‘struct neuMot’ERROR
            queu = p;
            p = NULL;
    }
     
    void Centre::CreeCentre() {
            for (int i = 0; i < 8; i++) {
                    ajoutNeu();
            }
    }
    string Centre::VisualiserCentre() {
            neuMot* p = new neuMot(NULL);     //invalid use of incomplete type ‘struct neuMot’ ERROR
            neuCarte* q = new neuCarte('A');
            string s = "";
            p = tete;                         //‘tete’ was not declared in this scope ERROR
            while (p = p->next) {             //invalid use of incomplete type ‘struct neuMot’ ERROR
                    q = p->data;              //invalid use of incomplete type ‘struct neuMot’ ERROR
                    s = s + q->data;
            }
            return s;
    }
     
     
    /*
     * Carte.h
     *
     *  Created on: 30 avr. 2013
     *      Author: bravvve
     */
     
    #ifndef CARTE_H_
    #define CARTE_H_
     
    #include"neuCarte.h"
     
    class Centre;
    class Carte{
    public:
            Carte();
            void ajoutNeu(char x);
            void CreeCarte();
            void VisualiserCarte();
     
            neuCarte* tete;  //expected ‘;’ before ‘*’ token ERROR
            neuCarte* queu;  //expected ‘;’ before ‘*’ token ERROR
     
            int complet;
    };
    #endif /* CARTE_H_ */
     
    /*
     * Carte.cpp
     *
     *  Created on: 30 avr. 2013
     *      Author: bravvve
     */
     
    #include"Carte.h"
     
     
     
    #include <iostream>
     
    Carte::Carte(){
    tete = new neuCarte('0');
    queu=tete;
    complet=0;
     
    }
     
    void Carte::ajoutNeu(char x){
            neuCarte* q= new neuCarte(x);
            queu->next=q;
            queu=q;
            q=NULL;
    }
     void Carte::CreeCarte(){
     
    for(int i=49;i<123;i++){
    if (i==58)i=65;if(i==91)i=97;
            ajoutNeu((char)i);
    //      cout << (char)i << endl;
     
     }
    complet=1;
     }
    void Carte::VisualiserCarte(){
            neuCarte* q=tete;
            cout << q->data << endl;
            while(q=q->next)
                    cout << q->data << endl;
     
    }

how can i fix that

[toum]

You can use forward declaration only when the compiler does not need to know what the type/class really is.

For example it's correctly used in Centre.h. Since you're only passing pointers, the internal details of the pointed to classes are not needed.

But in Centre.cpp you're creating new neuMots using the constructor. Therefore these details are needed, and you have to provide the full definition of the neuMot class.