From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Subject: Re: Why constant components are not permitted ?
Date: Fri, 25 Nov 2011 18:41:36 +0100
Date: 2011-11-25T18:41:36+01:00 [thread overview]
Message-ID: <9ja2aiFla6U1@mid.individual.net> (raw)
In-Reply-To: <14efc07c-744c-4f9a-905b-b9e3ad353e55@cc2g2000vbb.googlegroups.com>
On 11-11-25 11:06 , AdaMagica wrote:
> Useful applications for constant components could be (this is what you
> can have in C++):
>
> record -- *not* Ada
> Name: constant String := "James Bond";
> Id : constant Positive := 007; -- e.g employee number of a company
> other variable components
> end record;
The original poster specified the constant value in the declaration of
the record *type*, not separately for each record *object*. This is what
I do not understand: what is the use of a value that is the same for all
objects in which it can appear?
The "type constants" that Ada now provides are the attributes of a type
(tag, size, and so on), as Ludovic pointed out.
I understand that some would like to have a "write once" kind of record
component that can be given a value once, when a record object is
created, and cannot be changed afterwards. Discriminants are like that
in Ada, but cannot be of arbitrary type.
--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .
next prev parent reply other threads:[~2011-11-25 17:41 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-24 18:14 Why constant components are not permitted ? David Sauvage
2011-11-24 19:06 ` anon
2011-11-24 19:49 ` David Sauvage
2011-11-24 22:55 ` Georg Bauhaus
2011-11-24 23:53 ` anon
2011-11-24 19:46 ` Ludovic Brenta
2011-11-25 9:10 ` Dmitry A. Kazakov
2011-11-25 10:23 ` Ludovic Brenta
2011-11-25 10:45 ` Dmitry A. Kazakov
2011-11-25 6:56 ` Niklas Holsti
2011-11-25 9:53 ` Yannick Duchêne (Hibou57)
2011-11-25 10:06 ` AdaMagica
2011-11-25 10:16 ` AdaMagica
2011-11-25 10:56 ` Yannick Duchêne (Hibou57)
2011-11-25 17:41 ` Niklas Holsti [this message]
2011-11-26 0:23 ` anon
2011-11-29 4:10 ` Randy Brukardt
2011-11-29 7:55 ` David Sauvage
2011-11-29 10:55 ` Yannick Duchêne (Hibou57)
2011-11-29 11:17 ` Mark Lorenzen
2011-11-26 10:22 ` Pascal Obry
2011-11-26 10:59 ` Dmitry A. Kazakov
2011-11-25 7:03 ` AdaMagica
2011-11-25 9:12 ` Dmitry A. Kazakov
2011-11-25 9:57 ` Yannick Duchêne (Hibou57)
2011-11-25 10:22 ` Dmitry A. Kazakov
2011-11-25 11:00 ` Yannick Duchêne (Hibou57)
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