virtual functions

[werjocks]

I'm having a strange problem getting virtual functions to work... I get an "unresolved external symbol" error.
The virtual function is declaired and defined in the parent, and in one of the children it is overwritten.

If I simply move the overwritten function definition of the child into its header, I get no compilation problems.

I'm using Visual Studio 2003.

Any ideas?

 

[cpjust]

Post some code and we'll see what we can find.

 

[uolj]

Sounds like the source file for the child isn't included in the project. Either that or you forgot the ClassName:: when implementing the function.

 

[werjocks]

theres alot of code that was already working, but I'll include the relevent stuff....syntactically, I don't see anything missing...

//From parent header (ElectricComponent.h):
class ElectricComponent
{
public:
...
virtual void test();
...
};


//From parent (node.cpp):
#include "ElectricComponent.h"
...
void ElectricComponent::test()
{

}

//From child header (components.h):
#include "ElectricComponent.h"
class wire : public ElectricComponent
{
public:
...
void test();
...
};

//From child: (wire.cpp)
#include "components.h"
...
void wire::test()
{

}

//Errors produced:
OpenGL View Class error LNK2001: unresolved external symbol "public: virtual void __thiscall wire::test(void)" (?test@wire@@UAEXXZ)
OpenGL View Class error LNK2001: unresolved external symbol "public: virtual void __thiscall wire::test(void)" (?test@wire@@UAEXXZ)
OpenGL View Class fatal error LNK1120: 1 unresolved externals

if I just define the wire::test() as a part of the class definition in the header, no complaints. Could a syntax error somewhere else cause this kind of problem?

 

[uolj]

Is wire.cpp part of your project?

 

[werjocks]

sorry guys, Im an idiot. Someone stuck a #ifdef in the middle of my file. None of the new functions were actually being compiled. Heres to stupidity at its finest.

Thanks for the help.