(c++) Declaring a class member in a class

Question

I am trying to create a CBuffer member in every CClient class like this :

#ifndef CCLI_INC
#define CCLI_INC
#include "CBuffer.h"
#include "main.h"

    class CClient
    {
    private:

        CBuffer *m_buffer;


    public:
        CClient();



    };

but this code gives me

 error C2143: syntax error : missing ';' before '*'
 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

Although I have included cbuffer.h header, it gives this weird error..

What's in CBuffer.h? You will get this error if CBuffer is unknown. — Maurice Gilden, May 15 '12 at 13:30

score 2 · Accepted Answer · answered May 15 '12 at 13:29

2

Forward declare CBuffer and lose the include.

#ifndef CCLI_INC
#define CCLI_INC
#include "main.h"
class CBuffer;
class CClient
{
private:

    CBuffer *m_buffer;
public:
    CClient();
};

answered May 15 '12 at 13:29

Luchian Grigore

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yeah thanks it didn't give any errors. can you please explain why should i re-define class ? – deniz May 15 '12 at 13:46
@deniz you're not re-defining the class, only declaring it. When you only use it as a pointer, or parameter, or return type, you don't need a full definition, but only to tell the compiler that a class with that name exists. And forward declarations should be prefered to inclusions when possible. – Luchian Grigore May 15 '12 at 13:48
should i declare it on each file i will use ? by the way main.h includes all of the header files with #pragma once. – deniz May 15 '12 at 13:51
@deniz if you can, yes. Always prefer forward-declaration instead of an include. Refer to this answer for reasons why you should do so - http://stackoverflow.com/questions/9906402/should-one-use-forward-declarations-instead-of-includes-wherever-possible/9906429#9906429 – Luchian Grigore May 15 '12 at 14:06

(c++) Declaring a class member in a class

1 Answers1