Re: Normalize_Scalars

["Alex R. Mosteo" <devnull@mailinator.com>]

Simon Wright wrote:

> "Alex R. Mosteo" <devnull@mailinator.com> writes:
> 
>> Maciej Sobczak wrote:
>>
>>> gautier_niouzes@hotmail.com wrote:
>>>> BTW
>>>> - it seems that Normalize_Scalars is in Ada 95, Initialize_Scalars is
>>>> GNAT-only.
>>> 
>>> Portable code? :-)
>>> 
>>> But to be frank, I'm fine with GNAT-only Initialize_Scalars. Thank you
>>> for pointing me in this direction.
>>
>> But bear in mind they do opposite things!
> 
> ?
> 
> Normalize_Scalars: "This pragma ensures that an otherwise
> uninitialized scalar object is set to a predictable value, but out of
> range if possible.' (ARM95)
> 
> Intialize_Scalars: "This pragma is similar to Normalize_Scalars
> conceptually ..." (GNATRM)

Mmmm I had the following idea about them:

Normalize_Scalars should tries to cause an exception as soon as possible,
because it initializes to an /invalid/ value.

ITOH, Initialize_Scalars will use a /valid/ value for the initialization.

So the former should expose bugs and the latter hide them, for programs that
don't do proper initializations.

But I've seen after your warn that Initialize_Scalars is tailored by the user,
so my remembrances can come from a particular use of this pragma...