From: mab@dst17.wdl.loral.com (Mark A Biggar)
Subject: Re: Valid Attribute and Unchecked Conversion
Date: 1996/10/07
Date: 1996-10-07T00:00:00+00:00 [thread overview]
Message-ID: <53b658$c71@wdl1.wdl.lmco.com> (raw)
In-Reply-To: 32550731.167EB0E7@swl.msd.ray.com
In article <32550731.167EB0E7@swl.msd.ray.com> Karl Cooper {46901} <ktc@swl.msd.ray.com> writes:
>John Herro wrote:
>> I could be wrong, but I thought that Unchecked_Conversion is erroneous in
>> _any_ case. I heard that the first validated Ada compiler, Ada/Ed, took
>> advantage of that fact and generated code to raise Program_Error wherever
>> the program tried to make use of Unchecked_Conversion.
>> Is this true, and if so, has any of it changed with Ada 95 and the new
>> 'Valid attribute?
>No, see the Ada83 reference manual 13.10, and the Ada95 reference
>manual 13.9 and 13.9.1. Unchecked_Conversion leads to erroneous
>behavior in some cases, but not in others. In my opinion, the
>Ada95 reference manual is clearer when describing the safe uses
>of Unchecked_Conversion.
Why was the Unchecked_Conversion of an invalid scalar made erroneous in LM 95
instead of a bounded error like the coresponding uninitialized variable case?
--
Mark Biggar
mab@wdl.lmco.com
next prev parent reply other threads:[~1996-10-07 0:00 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-09-22 0:00 Rules for Representation of Subtypes Matthew Heaney
1996-09-23 0:00 ` David C. Hoos, Sr.
1996-09-23 0:00 ` Samuel T. Harris
1996-09-26 0:00 ` David C. Hoos, Sr.
1996-09-23 0:00 ` Robert A Duff
1996-09-24 0:00 ` Robert Dewar
1996-09-24 0:00 ` Robert Dewar
1996-09-26 0:00 ` Keith Thompson
1996-09-26 0:00 ` Matthew Heaney
1996-09-27 0:00 ` Robert Dewar
1996-09-27 0:00 ` Robert A Duff
1996-09-27 0:00 ` Robert Dewar
1996-09-27 0:00 ` Robert A Duff
1996-09-23 0:00 ` Robert A Duff
1996-09-24 0:00 ` Matthew Heaney
1996-09-26 0:00 ` Robert A Duff
1996-09-26 0:00 ` Larry Kilgallen
1996-09-27 0:00 ` Robert A Duff
1996-09-27 0:00 ` Mark A Biggar
1996-09-30 0:00 ` Robert A Duff
1996-10-01 0:00 ` Larry Kilgallen
1996-10-01 0:00 ` Robert A Duff
1996-10-01 0:00 ` Samuel Tardieu
1996-10-01 0:00 ` Valid Attribute and Unchecked Conversion Matthew Heaney
1996-10-02 0:00 ` Robert A Duff
1996-10-04 0:00 ` Keith Thompson
1996-10-04 0:00 ` Matthew Heaney
1996-10-07 0:00 ` Robert Dewar
1996-10-09 0:00 ` Keith Thompson
1996-10-04 0:00 ` Robert A Duff
1996-10-04 0:00 ` Robert Dewar
1996-10-11 0:00 ` Norman H. Cohen
1996-10-12 0:00 ` Robert Dewar
1996-10-06 0:00 ` Keith Thompson
1996-10-07 0:00 ` Robert Dewar
1996-10-09 0:00 ` Keith Thompson
1996-10-07 0:00 ` Ken Garlington
1996-10-08 0:00 ` Alan Brain
1996-10-07 0:00 ` Kenneth Almquist
1996-10-07 0:00 ` Robert Dewar
1996-10-10 0:00 ` Ken Garlington
1996-10-11 0:00 ` Robert Dewar
1996-10-14 0:00 ` Keith Thompson
1996-10-14 0:00 ` Ken Garlington
1996-10-01 0:00 ` Rules for Representation of Subtypes Ken Garlington
1996-09-28 0:00 ` Larry Kilgallen
1996-09-29 0:00 ` Robert A Duff
1996-09-29 0:00 ` Larry Kilgallen
1996-09-29 0:00 ` Matthew Heaney
1996-09-30 0:00 ` Robert A Duff
1996-10-01 0:00 ` Ken Garlington
1996-10-02 0:00 ` Robert A Duff
1996-10-02 0:00 ` Ken Garlington
1996-10-06 0:00 ` Robert Dewar
1996-09-29 0:00 ` Matthew Heaney
1996-09-30 0:00 ` Robert Dewar
1996-09-30 0:00 ` Matthew Heaney
1996-09-30 0:00 ` Robert A Duff
1996-10-03 0:00 ` Robert Dewar
1996-10-02 0:00 ` Valid Attribute and Unchecked Conversion Robert I. Eachus
1996-10-02 0:00 ` Matthew Heaney
1996-10-02 0:00 ` George Haddad
1996-10-03 0:00 ` John Herro
1996-10-04 0:00 ` Karl Cooper {46901}
1996-10-07 0:00 ` Mark A Biggar [this message]
1996-10-08 0:00 ` Robert Dewar
1996-10-05 0:00 ` Robert Dewar
1996-10-06 0:00 ` Keith Thompson
1996-10-14 0:00 ` Robert A Duff
1996-09-27 0:00 ` Rules for Representation of Subtypes Matthew Heaney
1996-09-27 0:00 ` Robert A Duff
-- strict thread matches above, loose matches on Subject: below --
1996-10-03 0:00 Valid Attribute and Unchecked Conversion Franco Mazzanti
1996-10-04 0:00 Franco Mazzanti
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