Re: General integer-types.

["J-P. Rosen" <rosen@adalog.fr>]

Le 07/04/2013 03:45, Shark8 a écrit :
>     Generic
> 	Size : Positive;
>     Package SWF_Integer is
> 	Exp : Constant Positive := Size-1;
> 	
> 	-- For some reason adding the "New Long_Long_Integer" allows
> 	-- this to compile... but it might ignore the Size aspect.
> 	Type Signed is New Long_Long_Integer Range -2**Exp..2**Exp-1
> 	with Size => Size;
>         
>         -- This doesn't work at all; Size is not static.	
> 	Type Unsigned is Mod 0..2**Size
> 	with Size => Size;
> 	
>     End SWF_Integer;
> 
A type definition must be static, and a size aspect too. A generic
formal is never static, therefore you can't define a type from a generic
parameter. (but of course, a constraint needs not be static, this is why
it works as a derived type). But then, all instantiations will use the
same size as Long_Long_Integer, which is likely not what you want.

-- 
J-P. Rosen
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