public inbox for gcc-help@gcc.gnu.org
 help / color / mirror / Atom feed
From: Eljay Love-Jensen <eljay@adobe.com>
To: Ming-Chia Jiang <jmc@wire.cs.nthu.edu.tw>, gcc-help@gcc.gnu.org
Subject: Re: extern functions in header file
Date: Fri, 10 Sep 2004 10:40:00 -0000	[thread overview]
Message-ID: <6.1.2.0.2.20040910053141.02d76340@iplan-mn.corp.adobe.com> (raw)
In-Reply-To: <20040910062659.M23072@wire.cs.nthu.edu.tw>

Hi Ming-Chia,

 >Is there any difference between declaring functions with prefix "extern" 
and without "extern" keyword in header files?

 From a C++ vantage point...

Effectively (by and large), no there's no difference.

Philosophically, yes.  Some consider (including myself) that supplying the 
(optional) <code>extern</code> keyword is good practice because it is 
self-documenting code.

Also, be aware that <code>extern "C"</code> has several important 
(critical!) implications regarding C++ code.

Also, in some areas, <code>extern</code> is REQUIRED to distinguish 
something that is "just a declaration" from being mistaken for a 
"definition" (without having the <code>extern</code>).  See Stroustrup's 
C++ Programming Language (3rd or special edition) section 9.2.

I haven't done C work since 1990, so my comments may not be appropriate for 
C "good style / best practices".

HTH,
--Eljay

  reply	other threads:[~2004-09-10 10:40 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-09-10  6:37 Ming-Chia Jiang
2004-09-10 10:40 ` Eljay Love-Jensen [this message]
2004-09-10 11:04   ` Sriharsha Vedurmudi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=6.1.2.0.2.20040910053141.02d76340@iplan-mn.corp.adobe.com \
    --to=eljay@adobe.com \
    --cc=gcc-help@gcc.gnu.org \
    --cc=jmc@wire.cs.nthu.edu.tw \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).