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From: x1y2z3@my-dejanews.com
Subject: Rational Apex and RM 7.4(2)
Date: 1998/08/06
Message-ID: <6qbomp$s9k$1@nnrp1.dejanews.com>#1/1
X-Deja-AN: 378461651
Organization: Deja News - The Leader in Internet Discussion
X-Article-Creation-Date: Thu Aug 06 08:06:51 1998 GMT
Newsgroups: comp.lang.ada
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Date: 1998-08-06T00:00:00+00:00
List-Id: <comp.lang.ada>

Hi,

we have some code containing deferred constants which are imported from
C. Gnat has no trouble with this, however I was told by a client that
their Rational Apex compiler did not like those constants (I don't know
of any specific error messages).

The RM says in 7.4(2)  "A deferred constant declaration requires a
completion, which shall be a full constant declaration ([...]), or a
pragma Import (see Annex B).", so what we are doing seems ok.

Has anyone else come across this problem (if it is a problem), or are
we doing something "naughty"?

  package A is
    ...
    package B is
       type Foo is private;
       ...
    private
       type Foo is new System.Address;
    end B;

    Bar : constant B.Foo;
    ...
  private
    pragma Import (C, Bar, "C_Bar");
  end A;

A workaround for Apex is to declare a variable in A's private part,
Import that and use the variable to complete the constant:

  private
    Temp_Bar : B.Foo;
    pragma Import (C, Temp_Bar, "C_Bar");
    Bar : constant B.Foo := Temp_Bar;
  end A;

This gets rather verbose when setting up a dozen constants. Any
better ideas?

Andrew.

--
+----------------------------------------------------------------------+
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