Re: [boost] Re: Re: Re: Re: Formal Review: FOREACH macro

From: Iain K. Hanson (iain.hanson_at_[hidden])
Date: 2005-05-04 07:59:27

On Tue, 2005-05-03 at 13:38 -0400, Arkadiy Vertleyb wrote:
> "Iain K. Hanson" <iain.hanson_at_[hidden]> wrote
> 
> > Design and Evolution of C++ by Bjarne Stroustrup.
> >
> > >From the end of chapter 18 "The C Preprocessor " ( last Para ) :
> >
> > "I'd like to see Cpp abolished. However, the only realistic and
> > responsible way of doing that is first to make it redundant, then
> > encourage people to use the better alternatives, and <em> then </em> -
> > years later - banish Cpp into the program development with the other
> > extra-linguistic tools where it belongs."
> 
> With all due respect -- this was written more than 11 years ago -- you
> cannot literally apply this now...

Why not? The arguments that the chapter uses are as valid today as when
written.
> 
> Regarding preprocessor -- this is the only built-in code generator in C++,
> except template metaprogramming, which is limited in this regard.  And code
> generation is crucial for library writers.  You don't use preprocessor -- 
> you end up with external tools, like MFC wizards or IDL compiler.  I
> strongly prefer macros.
> 

The preprocessor is NOT a code generator IMHO. It is a textual
substitution processor. In some ways I regard external tools as more
honest as they do not pretend to be C++ source code.

> Basically the question is: if you don't use the preprocessor, can you
> achieve the same without it (external tools don't count) and without
> violating the DRY principle?  If yes, you probably better of without it.  If
> no -- I don't understand the reason to reject macros.
> 

IMHO external tools that do text substitution are equivilent to the Cpp
and do count. If you are after Good ( TM ) code generation tools then I
would go for graphical case tools that understand the language and type
system.

DRY?

/ikh

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