Re: DYNAMIC ADA TASK CREATION?

[Dmitry A. Kazakov <mailbox@dmitry-kazakov.de>]

On 30 Jun 2003 08:01:29 -0700, mheaney@on2.com (Matthew Heaney) wrote:

>Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote in message news:<0gpvfv49qaa0b62ab5m0kg39kka66sis8t@4ax.com>...
>> On Sat, 28 Jun 2003 07:25:02 GMT, "Robert I. Eachus"
>> <rieachus@attbi.com> wrote:
>> 
>> >    generic
>> >      type Element is limited private;
>> 
>> A short question. Why not:
>> 
>>    type Element (<>) is limited private;
>> 
>> [I am using this in my containers because it is weaker than just
>> limited private.]
>
>Because the type must be definite, of course!  Otherwise, how would
>you know how much space to allocate for the object?
>
>Consider the following type (as you've declared it above):
>
>package P is
>   type T (<>) is limited private;
>private
>   type T is limited null record;
>end P;
>
>Here's a little puzzle: how do you declare an instance of type T?

I thought the container has only pointers to instances which are
created by caller, but maybe I missed something.

[ An advantage in having (<>) for Element is that it could then have
T'Class as actual. For example:

type Operand is new Ada.Finalization.Limited_Controlled with private;
type Operand_Ptr is access all Operand'Class;
...
package Argument_Stack is new Limited_Stack
   (Element => Operand'Class, Pointer => Operand_Ptr);
]

---
Regards,
Dmitry Kazakov
www.dmitry-kazakov.de