Path: utzoo!mnetor!tmsoft!torsqnt!hybrid!scifi!bywater!uunet!microsoft!jimad
From: jimad@microsoft.UUCP (Jim ADCOCK)
Newsgroups: comp.lang.c++
Subject: Re: Problems maintaining header files
Message-ID: <70484@microsoft.UUCP>
Date: 5 Feb 91 19:00:51 GMT
References: <15917@reed.UUCP> <6107@stpstn.UUCP>
Reply-To: jimad@microsoft.UUCP (Jim ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 34

In article <6107@stpstn.UUCP> lerman@stpstn.UUCP (Ken Lerman) writes:
|In article <15917@reed.UUCP> minar@reed.bitnet (Nelson Minar,L08,x640,7776519) writes:
|:
|:In C, I barely managed to keep all my header files straight and organized.
|:C++ just compounds my problems.
|
|...
|
|:
|:Are constructs like '#pragma once' just entirely common in C++ headers? I
|:find them ugly..
|
|Objective-C (please hold the flames down to a dull roar) uses '#import
|<foo.h>' to mean the same thing as '#include <foo.h>' except do
|nothing if the file has already been imported.  This is MUCH nicer
|than '#pragma once' and might be a useful addition to C++.

I agree.  I think its silly that the most common [and unavoidable] use
of the preprocessor requires several lines of code to program.

Likewise, one could imagine an:

#export "foo.h" 
....
#endexport

directive that [in the simplest implementations] would have the effect of
copying the code found in the enclosed section, before macro expansion,
to the file "foo.h"

Such an export section would allow one write a complete class in one 
.c file, with the required .h file generated "automatically."  Smarter
implementations could only generate a new .h section if the .c export
section changed, could cache the #export section in memory, ....