Skip Unused Virtual Function

Question

I have main executable and two functions that are dereferenced to DLL.

class CPluginInterface
{
public:
    virtual void A(void) = 0;
    virtual void B(void) = 0;
};

I created DLL like this

//Main.h
#include "Function.h"

class CForward : public CPluginInterface
{
public:
    //void A(void);
    void B(void);
};

//Main.cpp
#include "Main.h"

/*void CForward::A(void)
{
    //A Function is commented because it is not used
}*/

void CForward::B(void)
{
    //Do something here
}

extern "C"
{
    // Plugin factory function
    //void __declspec(dllexport) __cdecl A(void) { }
    void __declspec(dllexport) __cdecl B(void) { }
}

However the program is crashed because A(void) doesn't exist when the main executable dereferencing it. How to skip A(void)?

If I create the DLL like this, it works fine.

//Main.h
#include "Function.h"

class CForward : public CPluginInterface
{
public:
    void A(void);
    void B(void);
};

//Main.cpp
#include "Main.h"

void CForward::A(void)
{
    //Do something here
}

void CForward::B(void)
{
    //Do something here
}

extern "C"
{
    // Plugin factory function
    void __declspec(dllexport) __cdecl A(void) { }
    void __declspec(dllexport) __cdecl B(void) { }
}

NB: I create Plugin Interface.

score 1 · Accepted Answer · edited May 23 '17 at 12:22

1

The =0 suffix on your interface's virtual functions indicate that they are pure virtual and that you are required to override them when inheriting from the base class. In your first example CForward is an abstract class because you have not overridden A, thus you cannot create an instance of CForward.

https://stackoverflow.com/a/2652223

edited May 23 '17 at 12:22

Community

1
1

answered Mar 08 '15 at 22:49

Matthew James Briggs

2,085
2
28
58

That's great, David. If you up vote the answer and click the check mark I get some reputation points and your question will show up as answered when other folks are searching on this topic. – Matthew James Briggs Mar 10 '15 at 04:21
1

Oh, sorry. I didn't know it. Done. Thanks :) – DavidJr Mar 11 '15 at 07:16

Skip Unused Virtual Function

1 Answers1