Re: Confused about Attribute Size?

[Patrick Hohmeyer <pi3_1415926536@yahoo.ca>]

And Zebylon has spoken :

> Hi,
> 
> I'm a newbie in Ada but I saw an Ada example that confused me a bit, here
> it is:
> 
> type My_Type is
>     (startbit,
>      endbit,
>      timeout,
>      spare,
>      nextbit,
>      ......
>      ......
>      lastbit);
> 
> for My_Type use
>     (startbit =>0,
>      endbit=>1,
>      timeout=>2,
>      spare=>3,
>      nextbit=>4,
>      ......
>      ......
>      lastbit=>15);
> 
> for My_Type'Size use 8;
> 
> type My_Type_Array is array (My_Type) of Boolean;
> 
> What I don't understand is how you can assign the size to 8 bits? How will
> this work when
> there are 16 bits in the type? What will be the size of the array?
> This example was in Ada 83 could this be a clue?
> 
> Thanks
> 
> /S

Hint : My_Type is an enumeration type.

Ex : Character is also an enumeration,
there are 256 possible characters,
does this make a character 256 bit ? ;-)

The array will be 16 or 2 bytes
(if you use the pragma pack, what I suspect)
One boolean per possible value of My_Type.

Hint2 : try some general tutorials befor trying to understand chapter 13.

-- 
Patrick Hohmeyer