Dynamic Allocation of 2D array of <class>

[lestat]

I have switched to a new compiler (gcc/g++ 3.2 on rh linux 8.0) and I
cannot seem to dynamically allocate two dimentonal arrays (or even
singel dimetional arrays!) of any user defined classes.

Here is a simple example of an array of user defined class that *used*
to work, but doesn't anymore:
-------------------begin code-----------------------
#include <iostream>
#include <stdio.h>
#include <stdlib.h>

using namespace std;

class Pixel
{
public:
Pixel();

int i;
int j;
};

int main()
{
Pixel p[4];

for (int i=0;i<4;i++)
{
p[i].i=i;
p[i].j=i*i;
}

for (int i=0;i<4;i++)
{
cout<<p[i].i<< " "<<p[i].j<<endl;
}
return 0;
}
----------------------end code------------------

Here is the error message I get when I compile:

[root@voyager hw5]# g++ -o dblarray dblarray.cpp
/tmp/ccMX0JlL.o: In function `main':
/tmp/ccMX0JlL.o(.text+0x30): undefined reference to
`Pixel::Pixel[in-charge]()'
collect2: ld returned 1 exit status
[root@voyager hw5]#

I get the same error if I try to allocate pointers of pointers etc...

Any idea what I'm missing?

--Dave

[Alf P. Steinbach]

On Fri, 10 Oct 2003 23:04:11 GMT, lestat <le****@student.umass.edu> wrote:

I have switched to a new compiler (gcc/g++ 3.2 on rh linux 8.0) and I
cannot seem to dynamically allocate two dimentonal arrays (or even
singel dimetional arrays!) of any user defined classes.

Here is a simple example of an array of user defined class that *used*
to work, but doesn't anymore:
-------------------begin code-----------------------
#include <iostream>
#include <stdio.h>
#include <stdlib.h>

using namespace std;

class Pixel
{
public:
Pixel();

int i;
int j;
};

int main()
{
Pixel p[4];

for (int i=0;i<4;i++)
{
p[i].i=i;
p[i].j=i*i;
}

for (int i=0;i<4;i++)
{
cout<<p[i].i<< " "<<p[i].j<<endl;
}
return 0;
}
----------------------end code------------------

Here is the error message I get when I compile:

[root@voyager hw5]# g++ -o dblarray dblarray.cpp
/tmp/ccMX0JlL.o: In function `main':
/tmp/ccMX0JlL.o(.text+0x30): undefined reference to
`Pixel::Pixel[in-charge]()'
collect2: ld returned 1 exit status
[root@voyager hw5]#

I get the same error if I try to allocate pointers of pointers etc...

Any idea what I'm missing?

You've declared a default constructor but never defined it.

[lestat]

Alf P. Steinbach wrote:

On Fri, 10 Oct 2003 23:04:11 GMT, lestat <le****@student.umass.edu> wrote:

I have switched to a new compiler (gcc/g++ 3.2 on rh linux 8.0) and I
cannot seem to dynamically allocate two dimentonal arrays (or even
[snip]
Any idea what I'm missing?

You've declared a default constructor but never defined it.

Well that was easy. Thank you very much, I've been stuck on this for hours!