Inheritance, and code not running
 

Ah right! Im on my first steps on c++, What Im trying to do is
have this "basic node" class wich just take an id and from there
usign inheritance make "linked list node" and "binary tree node" classes my code so far looks like this

void main()

{

sLink* pChainLink; //sLink stays for single list link 

sLink ChainLinkNo1 (pChainLink, 1);

sLink ChainLinkNo2 (ChainLinkNo1, 2);

sLink ChainLinkNo3 (ChainLinkNo2, 3);



sLink * tmp = ChainLinkNo3;

while(tmp != 0){

 cout <<  tmp->Id();

 tmp = ChainLinkNo3.Next();

}

 

}

and the other 2 headers

//sLink.h

class sLink : public Link

{

public:

 sLink (sLink* pNext, int id): Link(id), _pNext (pNext)   {}

  sLink * Next () const { return _pNext; }

private:

  sLink * _pNext;

};

link.h //the basic node

class Link

{

public:

Link (int id): _id (id) {}

int Id () const { return _id; }

private:

int _id;

};

the compiler error says:

(red code position ) 'initializing' : cannot convert from 'Link *' to 'sLink *'

Some reason why's ... thanks

Re: Inheritance, and code not running
 

Your problem is actually the first four lines of the main() function. I've added comments to the code that are related to problems on each line.

void main()    // main should return int, not void

{

sLink* pChainLink; // uninitialised pointer

sLink ChainLinkNo1 (pChainLink, 1);   // undefined behaviour: accessing value of uninitialised pointer

sLink ChainLinkNo2 (ChainLinkNo1, 2);    // compiler error: ChainLinkNo1 not a pointer, sLink's constructor expects one

sLink ChainLinkNo3 (ChainLinkNo2, 3);  // compiler error: ChainLinkNo2 not a pointer, sLink's constructor expects one

The only reason the compiler is complaining about the line you have highlighted is that it is the only constructor that might be invoked by your code, but you've provided the wrong type of argument.

Re: Inheritance, and code not running
 

pretty good answer GOT IT ! thx