From: David Rasmussen <pinkfloydhomer@yahoo.com>
Subject: Re: with and use
Date: Wed, 10 Jul 2002 15:45:13 +0200
Date: 2002-07-10T15:45:13+02:00 [thread overview]
Message-ID: <3D2C3A69.8070207@yahoo.com> (raw)
In-Reply-To: aghchh$oqb$1@s1.read.news.oleane.net
Jean-Pierre Rosen wrote:
> "David Rasmussen" <pinkfloydhomer@yahoo.com> a �crit dans le message
> news: 3D2C2FF9.4020300@yahoo.com...
>
>> First of all, what does this message from GNAT mean:
>>
>> "with" can only appear in context clause
>>
>
> A context clause is a clause that appears *before* a compilation
> unit. A with clause cannot appear *inside* anything else, so this
> basically means that you have to move the with clause on top of the
> unit.
>
Thanks!
>
>> Secondly, where is with and use typically used, and what is the
>> difference between them?
>>
>
> A with clause means that a compilation unit needs the services from
> another *compilation unit* (i.e. a package, subprogram or generic
> which is separately compiled).
>
> A use clause factors out a *package*, i.e. you don't have to repeat
> the package name in front of every element. Since a package can (but
> needs not) be a compilation unit, there are cases where both clauses
> can be applied, but they are really orthogonals.
>
So with corresponds roughly to an #include of some header file that
defines prototypes etc. for some other compilation unit in C++, and use
corresponds roughly to "using namespace Whatever", assuming that the
things included were in a seperate namespace?
"with" and only appear at the top of a unit. Where can "use" appear?
/David
next prev parent reply other threads:[~2002-07-10 13:45 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-07-10 13:00 with and use David Rasmussen
2002-07-10 13:25 ` Jean-Pierre Rosen
2002-07-10 13:45 ` David Rasmussen [this message]
2002-07-10 14:24 ` Jean-Pierre Rosen
2002-07-10 19:17 ` Ted Dennison
2002-07-10 17:18 ` Jeffrey D. Cherry
-- strict thread matches above, loose matches on Subject: below --
2002-07-10 17:20 Gautier direct_replies_not_read
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