From: Robert A Duff <bobduff@shell01.TheWorld.com>
Subject: Re: generic function and overloading
Date: Thu, 18 Oct 2007 11:58:48 -0400
Date: 2007-10-18T11:58:48-04:00 [thread overview]
Message-ID: <wccabqgl8hz.fsf@shell01.TheWorld.com> (raw)
In-Reply-To: 1192688972.967825.31130@t8g2000prg.googlegroups.com
eliben <eliben@gmail.com> writes:
> Hello,
>
> I have a few "hardware" types, for example uint16 and uint32. And I
> want to write a functions that will set or clear bits of such types.
> For example:
>
> function Bit_Set(word: uint16; bitn: natural) return uint16;
>
> function Bit_Set(word: uint16; bitn: natural) return uint16 is
> mask: uint16 := 2**bitn;
> begin
> return word or mask;
> end Bit_Set;
>
> However, I realize that such a function would be almost completely
> duplicated for the uint32 type. In C++ I would probably define it as a
> template on the type of the word, and the compiler would do the job
> for me. In Ada, however, when using generics it doesn't seem I can
> leave the same function name for all types (as I would do in
> overloading). I can define a generic Bit_Set, but then I have to
> specialize it for uin16 and uint32 with different function names. Is
> there any way I could combine the effects of generics and overloading
> and get a single Bit_Set for all my types without writing the code N
> times ?
Others answered your main question.
But do you really want to do arithmetic on these types,
as well as setting/clearing bits? If all you want to
do is set/clear bits, you might want to consider using
a packed array of Boolean. Then to set the Nth bit you
can say:
X (N) := True;
Alternatively, a packed array of type Bit, where:
type Bit is range 0..1;
If the individual bit numbers have some specific meaning,
the index type could be an enumeration type.
- Bob
next prev parent reply other threads:[~2007-10-18 15:58 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-18 7:28 generic function and overloading eliben
2007-10-18 8:18 ` Jean-Pierre Rosen
2007-10-18 9:31 ` Dmitry A. Kazakov
2007-10-18 9:33 ` Dmitry A. Kazakov
2007-10-18 10:32 ` Georg Bauhaus
2007-10-18 11:07 ` Stephen Leake
2007-10-18 11:30 ` Stefan Lucks
2007-10-18 15:58 ` Robert A Duff [this message]
2007-10-18 20:20 ` Simon Wright
2007-10-18 21:23 ` Robert A Duff
2007-10-19 5:19 ` Simon Wright
2007-10-19 13:59 ` Robert A Duff
2007-10-18 18:58 ` Dr. Adrian Wrigley
2007-10-18 22:30 ` Adam Beneschan
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