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Date: Thu, 23 Dec 2004 00:22:41 +0000
From: Peter Edwards <peadar.edwards@gmail.com>
To: "M. Warner Losh" <imp@bsdimp.com>
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cc: grog@freebsd.org
cc: PeterJeremy@optushome.com.au
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Subject: Re: Header files with enums instead of defines?
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> 
> Or better yet, just use the array of error values already compiled
> into the programs that strerror() formats for you (you don't need to
> use strerror, just sys_errlist[]).

I'd dispute the "better yet": If used in code, "errno_t" is useful in
its own right. Even beyond the type safety, if used in a structure

> (gdb) print *structptr

Will print errno_t members properly, without requiring hints that
fields represent errno values, etc. (ie, it's a hint to the debugger
that something of type errno_t conveys more specific information than
a value between INT_MIN and INT_MAX.)
Although textual descriptions are better than the errno names to
users, "err_EBADF" means much more than "9" in a debug output to the
programmer running the debugger.

Sorry for splitting hairs. (But the bikeshed should definitely be blue)
-- 
Peadar.