help me with undefined references

[pavan734]

Hi,
Iam facing problem with undefined reference linking errors.
To explain in more detail..
I have a class called TOP. In its constructor I have instantiated many
other class objects using pointers.
Iam getting errors like
1. In function TOP::TOP(int) : undefined reference to
CHILD1::CHILD1(int, float).
2. In function TOP::TOP(int) : undefined reference to vtt for
CHILD2::CHILD2(char*)
3. In function TOP::TOP(int) : undefined reference to vtable for
CHILD3::CHILD3( )
4.In function TOP ::func() undefined reference to CHILD3:: func2()

What could be possible reasons for getting such errors.

 

[Ian Collins]

Hi,
Iam facing problem with undefined reference linking errors.
To explain in more detail..
I have a class called TOP. In its constructor I have instantiated many
other class objects using pointers.
Iam getting errors like
1. In function TOP::TOP(int) : undefined reference to
CHILD1::CHILD1(int, float).
2. In function TOP::TOP(int) : undefined reference to vtt for
CHILD2::CHILD2(char*)
3. In function TOP::TOP(int) : undefined reference to vtable for
CHILD3::CHILD3( )
4.In function TOP ::func() undefined reference to CHILD3:: func2()

What could be possible reasons for getting such errors.

You haven't linked the object files for those classes?

Using all upper case for class names is rather an odd style.

 

[Mukian]

Hi,

I think u have to do forward declaration of classes which you created
instances.

Regards,
Mukil

 

[Ian Collins]

Mukian wrote:

Please don't top post.

Hi,

I think u have to do forward declaration of classes which you created
instances.

Who's u?

The OP is getting linker errors, not compile errors.

 

[pavan734]

Hi,
Iam facing problem with undefined reference linking errors.
To explain in more detail..

What could be possible reasons for getting such errors.

I have found out that such errors will come if a function is declared
in a class and its definition is not provided, then also we get
undefined reference. But Iam thinking whether there are any other
reasons for such errors.

 

[Default User]

I have found out that such errors will come if a function is declared
in a class and its definition is not provided, then also we get
undefined reference. But Iam thinking whether there are any other
reasons for such errors.

Maybe. How we can we possibly tell if you hid information from us? SHOW
US THE CODE. Post a complete, minimal program the demonstrates the
problem.

Actually, before you do anything else, read this:

<http://www.parashift.com/c++-faq-lite/how-to-post.html#faq-5.8>




Brian