Re: header files

From: Francis Glassborow (francis_at_robinton.demon.co.uk)
Date: 04/05/04 

Date: Mon, 5 Apr 2004 20:58:43 +0100

In message <c4s9o6$k0i$1@newsg3.svr.pol.co.uk>, mike ttoouli
<mttoouli@yahoo.com> writes
>hi jeffc, sorry I wasn't being very clear.
>
>It was never my intention to create one big file - lots separate files, each
>being used by one another. All the code could just be written in .h files,
>and used by other .h files by including them (#include "filename.h" - can
>this be done with cpp files?).
>
>This would lead to the problem of including the same header file in more
>than one place in a large program, but by enclosing the code in each header
>file using:
>
>#ifndef FILENAME_H
>#define FILENAME_H
>..code...
>#endif
>
>then this would ensure that the header file is added only the first time it
>is encountered in a program, as after that FILENAME_H is defined.

Then your program will have to consist of a single monolithic
translation unit. The job of header files is to mediate between a
program written as multiple TU + one or more libraries.

One mamoth disadvantage of the monolithic approach is that every change
anywhere requires complete recompilation.

>
>well i think that makes sense. I've implemented a fairly large program only
>using header files, and I couldn't really see the point of .cpp files at
>all.

Sorry, but I do not believe you (I am sure you think you have buyt a
fairly large program would consist of tens of thousands of lines of
code.) If you cannot see the point of .cpp files I suspect you do not
understand the basics of organising work the way C and C++ have been
designed for. 

-- 
Francis Glassborow      ACCU
Author of 'You Can Do It!' see http://www.spellen.org/youcandoit
For project ideas and contributions: http://www.spellen.org/youcandoit/projects

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