Re: [Dev-C++] Where to include files

[xRxIxPx <xr...@gm...>]

At 08:15 AM 10/12/2003 -0400, Matthews wrote:
>Guard statements are lines like these in your header files:
>
>#ifndef FOOHEADER_H
>#define FOOHEADER_H
>
>int foo;
>char *foostring;
>//...

That should not happen! If you include this header in two different compile 
units (means .cpp files), your global objects will be defined in 2 object 
files making the linker bailing out errornously.
In general, you should only have const, static and extern variable 
declarations in your header files, and in ONE .cpp file the definition for 
your extern variables.


>#endif
>
>Then if two files include foo.h, it won't be recompiled because FOOHEADER_H
>has already been defined.



Only true for one compile unit.

Better have:
#ifndef FOOHEADER_H
#define FOOHEADER_H

extern int foo;
extern char *foostring;
//...
#endif

foo1.cpp
#include "fooheader.h"

foo2.cpp
#include "fooheader1.h"

int foo=631;
char* foostring=0;


Cheers.