c++ - undefined reference to constructor for argument -

good evening

i have small problem constructor. i'm trying build tree of different possible plays of board (to depthfirstsearch after). in node class constructor, want copy current board leaf tree. got error "undefined reference `board::board()'|" when try use board class instance argument node constructor.

if have idea of how correctly, i'm listening, don't see problem :(

here class node :

class node { private :     board      state;     list<node>  sons; public :                 node(board&);     void        addnode(board&); }; 

while doing node constructor, :

node::node(board& tab) {     state = tab;     sons = null; } 

my board class :

class board {  private :     int**           tab;     int             nbline;     int             nbcolumn;     position        emptyspot;  public  :                     board(int, int, play&); // initialised random positions                     board(int, int); // size, no values inside. node::node during constructor.     void            setvalue(position&, int);     void            setnbline(int m);     void            setnbcolumn(int n);     int             getvalue(position&);     int             getnbline();     int             getnbcolumn();     int             getemptyline();     int             getemptycolumn();     void            setemptyspot(position&);     position&       getemptyspot();      board&          operator=(board& source); }; 

edit : due people asking, here constructors of board:

    board::board(int m, int n, play& jeu) : tab{new int*[m]}, nbline{m}, nbcolumn{n}, emptyspot{n-1,m-1}{         int              x(1);         (int = 0; < m; ++i){             tab[i] = new int[n];              for(int j = 0; j < n; ++j) {                 tab[i][j] = x; x++;}}         tab[n-1][m-1]=0;        x=0;         while (x!=1000)        {         int numbers[] = { up, down, left, right };         int length = sizeof(numbers) / sizeof(int);         int randomnumber = numbers[rand() % length];          jeu.moves(*this, randomnumber);         x++;        }     }      board::board(int m, int n) : tab{new int*[m]}, nbline{m}, nbcolumn{n}, emptyspot{n-1,m-1}  {       (int = 0; < m; ++i){         tab[i] = new int[n];          for(int j = 0; j < n; ++j) {             tab[i][j] = 0;}} } 

it not strange. in node::node(board& tab) state default-initialized before make assignment. since doesn't explicitly, compiler calls board::board(), not defined. change node::node() to:

node::node(board& tab) : state(tab) , sons(null) { } 

remember, required, members must fully-initialized before body of constructor gets executed. classes containing reference members or instances of classes, not have default/copy constructor defined, must initialize them via initialization list.

also, if have defined operator=() in board, define copy constructor (rememeber rule of three):

class board { //...    board(const board&)   {     //make copy   }  }; 

edit

i think board's copy constructor should implemented way:

board(const board& origin) : tab(null) , nbline(origin.nbline) , nbcolumn(origin.nbcolumn) , emptyspot(origin.emptyspot) {   this->tab = new int*[this->nbline];    (int = 0; < m; ++i)     this->tab[i] = new int[this->nbcolumn];    //tab contains int's, let's simple memcpy()   memcpy(this->tab, origin.tab, sizeof(int) * this->nbline * this->nbcolumn); }