Re: controlled types and point of instanciation

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

Le 16/03/2018 à 15:39, Mehdi Saada a écrit :
> I make the humble request of an exegesis of this text: (from ada 95 the craft of oriented programming)
> "Since Ada.Finalization.Limited_Controlled and Ada.Finalization.Controlled are both library-level types, all controlled types must be derived by instantiation at library level. Since generic packages are treated as being declared at the point of instantiation, this means that JE.Lists can only be instantiated at library level, usually within the specification of another library package. This means that we can no longer use JE.Lists to build opaque types as [bellow]. Instantiating JE.Lists inside a package body is no longer permissible."

This was a rule of Ada95 intended to prevent accessing non existing
objects, but very annoying in practice, precisely because it forbad
instantiating the containers anywhere else than at library level.

Since Ada 2005, it has been replaced by a run-time check, so you don't
need to worry.

-- 
J-P. Rosen
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