Booelan Function and sizeof operator

Booelan Function and sizeof operator

[EMANUELE COSTA]

Hi everybody,
        I would like to know, if I can find something similar to the C
sizeof operator and  boolean functions on integer  in Ada. If
this is not the case how could I write something equal in Ada?

======================
Emanuele Costa
Pendle College
Lancaster University

costa@unix.lancs.ac.uk
======================

Re: Booelan Function and sizeof operator

[Robert Dewar]

Emanuele asks

"        I would like to know, if I can find something similar to the C
sizeof operator and  boolean functions on integer  in Ada. If
this is not the case how could I write something equal in Ada?"

sizeof correspond to 'Size in Ada

boolean functions are available on unsigned types, but not on signed
types in Ada (the effect of boolean functions on signed types in C
is implementation defined, and Ada prefers not to introduce this
particular implementation dependency).

Re: Booelan Function and sizeof operator

[Dale Stanbrough]

"sizeof correspond to 'Size in Ada"


...except of course that sizeof returns size in bytes, 
'size returns size in bits.

(I didn't want a repeat of a message posted here about
2 years ago from a student who was *amazed* that Ada
records could be *8* times larger than an equivalent C
struct :-).


Dale

Re: Booelan Function and sizeof operator

[David Wheeler]

EMANUELE COSTA (costa@UNIX.LANCS.AC.UK) wrote:
: Hi everybody,
:         I would like to know, if I can find something similar to the C
: sizeof operator and  boolean functions on integer  in Ada. If
: this is not the case how could I write something equal in Ada?


sizeof(int)  ===>   Integer'Size

I'm not sure what you mean by "boolean functions on integer".
If you want to _convert_ a Boolean to Integer, you can use 'Pos:

bool x;                   ==> X : Boolean;
printf("%d", (int) x);        Put(X'Pos);

If you mean "and", "or", etc., you can define a packed array of Booleans
and perform operations on the array.  In Ada 95, you can also use
modular types for "and", "or", etc.


--- David A. Wheeler
Net address: wheeler@ida.org

Re: Booelan Function and sizeof operator

[Samuel Tardieu]

>>>>> "David" == David Wheeler <wheeler@aphrodite.csed.ida.org> writes:

David> sizeof(int) ===> Integer'Size

I think you mean: sizeof(int) ===> Integer'Size/System.Storage_Unit

  Sam
-- 
"La cervelle des petits enfants, ca doit avoir comme un petit gout de noisette"
                                                       Charles Baudelaire

Re: Booelan Function and sizeof operator

[George Haddad]

Samuel Tardieu wrote:
>> "David" == David Wheeler <wheeler@aphrodite.csed.ida.org> writes: 
> David> sizeof(int) ===> Integer'Size
> 
> I think you mean: sizeof(int) ===> Integer'Size/System.Storage_Unit

Wouldn't it actually be:   :-)
   sizeof(int) ===> ((Integer'Size - 1)/System.Storage_Unit) + 1;

   (Just to drag things out a little more generally. :-))
-- 
I found these opinions on my doorstep, would you please give them a 
good home?