From: "Mike Silva" <mjsilva@jps.net>
Subject: Unchecked_Conversion on different sized types -- problem?
Date: 2000/01/13
Date: 2000-01-13T00:00:00+00:00 [thread overview]
Message-ID: <qXpf4.429$dw3.15200@news.wenet.net> (raw)
To do some prototyping I'm extending Michael Feldman's ANSI screen package a
bit, to allow colors, etc, and I ran into a question. I've enumerated
various attributes and set the enumerations to the corresponding ANSI codes,
and I'm using UC to convert the enumerated types to an Integer, to send via
Text_IO.Put(). I get a warning (GNAT 3.12p) that the types for the UC have
different sizes (not surprising), and I'm wondering if UC always does the
"right" thing here, i.e. zero-extending the smaller enum type when
converting to an Integer.
Here are some (reduced) relevant code bits:
type T is ( BLACK, WHITE );
for T use ( BLACK => 30, WHITE => 37 );
function T_to_int is new Unchecked_Conversion( T, Integer );
T_val : T := BLACK;
Text_IO.Put( Item => T_to_int( T_val )...
So, is T_to_int going to give me 30, as opposed to, say, all 32 bits
starting at the address of T_val? Can somebody tell me where in the LRM it
talks about this?
(It works "as expected" in this case, but I'm wondering what the rules are)
Also, there's not a simpler way to do this that I'm overlooking, is there?
Mike
next reply other threads:[~2000-01-13 0:00 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-01-13 0:00 Mike Silva [this message]
2000-01-13 0:00 ` Unchecked_Conversion on different sized types -- problem? Bryce Bardin
2000-01-13 0:00 ` Mike Silva
2000-01-13 0:00 ` Mike Silva
2000-01-14 0:00 ` Bryce Bardin
2000-01-14 0:00 ` Mike Silva
2000-01-14 0:00 ` Matthew Heaney
2000-01-13 0:00 ` Jim Rogers
2000-01-13 0:00 ` Mike Silva
2000-01-13 0:00 ` James S. Rogers
2000-01-13 0:00 ` reason67
2000-01-14 0:00 ` Keith Thompson
2000-01-16 0:00 ` David A. Cobb
2000-01-14 0:00 ` Jeff Carter
2000-01-14 0:00 ` Vladimir Olensky
2000-01-14 0:00 ` Werner Pachler
2000-01-14 0:00 ` reason67
2000-01-14 0:00 ` Bryce Bardin
2000-01-14 0:00 ` Wrap-Up (was Re: Unchecked_Conversion on different sized types -- problem?) Mike Silva
2000-01-15 0:00 ` Matthew Heaney
2000-01-15 0:00 ` Robert A Duff
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