Thread: Linked List Problems

Force of habit. Plus, there is no telling what system this code will run on.
If its running on a new high powered pc then your right.
If its running on a Wayne fuel dispenser, your wrong.
Can not till you about an I-pod because i've never programed one. But i'm willing to bet a simple void pointer check will not crash the system as fast as processing a void pointer.
c++ is not just for personal computers anymore.

what linker error are you getting?

Originally Posted by Nor

Force of habit. Plus, there is no telling what system this code will run on.
If its running on a new high powered pc then your right.
If its running on a Wayne fuel dispenser, your wrong.

We are talking about a rule mandated by the C++ Standard.

Originally Posted by Nor

Can not till you about an I-pod because i've never programed one. But i'm willing to bet a simple void pointer check will not crash the system as fast as processing a void pointer.

I think you mean null pointer, not void pointer, but of course new is not guaranteed to return a null pointer if memory could not be allocated, unless the nothrow version of new is used.

Originally Posted by cannsyl

the linker error i am getting is
undefined reference to 'operator<<(std:stream&, Song const&)'

So what does your function definition look like?

--
Mats

I didn't look at the rest of this thread but:

have you tried

Code:

std::ostream

and (i just made the following mistake too):

have you included <iostream> in the right place(s)?

Originally Posted by Nor

Force of habit. Plus, there is no telling what system this code will run on.

While that's a valid point, it's better to assume standards compliance until proven otherwise, or unless you know up front that a targetted system isn't compliant. Even if you had to insert a new failure check at some future point, that shouldn't be so bad -- well designed software shouldn't be calling new from that many distinct places, anyway.

If exceptions are available on your given platform set you should be using them, I guess is my point.

ok I am getting an error that says

Code:

linker error undefined reference to  'Song::artist'

but I am not sure where in the code it is...

Code:

//song.h
#ifndef SONG_H
#define SONG_H
#include <stdlib.h>
#include <iostream>
#include <ostream>
#include <string>
//#include "BobCatPod.h"
using namespace std;
//std::ostream;

class Song
{
   private:
      string title;    //dynamic allocation
      string artist;
      int size;
   public:
      Song();
      Song(string , string , int ); // constructor
      void setSize(int s);
      int getSize(); // access or
      void setTitle (string t);
      string getTitle();
      void setArtist (string a);
      string getArtist();
      void addSong (int);
      friend ostream& operator<<(ostream & os, const Song &s)
      {
      os << title;
      os  << artist;
      os << size;
      return os;
      }
      bool operator==(const Song& lhs)
      {
           if (strcmp (artist, lhs.artist) == 0)
           {if (strcmp (title, lhs.title) ==0)
            {if (size == lhs.size)
              return true;
            }
            }
            return false;
      }
      bool operator<(const Song& lhs)
      {
           if (artist < lhs.artist)
           { return true;
           }
           else if (artist > lhs.artist)
           {
               return false;
           }
           else if (title < lhs.title)
           {
                return true;
           }
           else if (title > lhs.title)
           {
                return false;
           }
           else if (size < lhs.size)
           {
                return true;
           }
           else
           {
               return false;
           }
      }
  
};
#endif