From: Denis Vlasenko <vda@ilport.com.ua>
To: Coywolf Qi Hunt <coywolf@gmail.com>
Subject: Re: Use enum to declare errno values
Date: Fri, 2 Dec 2005 14:07:02 +0200
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Cc: "linux-os (Dick Johnson)" <linux-os@analogic.com>,
       Paul Jackson <pj@sgi.com>, francis_moreau2000@yahoo.fr,
       linux-kernel@vger.kernel.org
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On Friday 02 December 2005 11:27, Coywolf Qi Hunt wrote:
> 2005/12/2, Denis Vlasenko <vda@ilport.com.ua>:
> > On Thursday 01 December 2005 22:01, linux-os (Dick Johnson) wrote:
> > > On Thu, 24 Nov 2005, Paul Jackson wrote:
> > >
> > > > If errno's were an enum type, what would be the type
> > > > of the return value of a variety of kernel routines
> > > > that now return an int, returning negative errno's on
> > > > error and zero or positive values on success?
> > >
> > > enums are 'integer types', one of the reasons why #defines
> > > which are also 'integer types' are just as useful. If you
> > > want to auto-increment these integer types, then enums are
> > > useful. Otherwise, just use definitions.
> >
> > There is another reason why enums are better than #defines:
> 
> This is a reason why enums are worse than #defines.

Why?

> > file.c:
> > ...
> > #include "something_which_eventually_includes_file.h"
> > ...
> > int f(int foo, int bar)
> > {
> >         return foo+bar;
> > }

This gets converted to "int f(int 123, int bar)" when foo
is a #define. Do you disagree that it is bad?
--
vda
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