pointers and protected objects

pointers and protected objects

[tonyg]

I can create pointers to protected objects, but how do I initialise the protected object as it is a limited type and the syntax

po_ptr := new Po_Type'(Po_Type_Instance) would not be allowed

Re: pointers and protected objects

[Simon Wright]

tonyg <tonythegair@gmail.com> writes:

> I can create pointers to protected objects, but how do I initialise
> the protected object as it is a limited type and the syntax
>
> po_ptr := new Po_Type'(Po_Type_Instance) would not be allowed

So far as I am aware, you can't; the PO needs to be self-initializing
(you can give the protected type discriminants, which may help)

Re: pointers and protected objects

[tonyg]

ah well shame. Thanks anyway. I am going to  implement each object in an array then, that should do the job,

do you know if I separate the body of the protected object in a different compilation file and what how I name the file in gnat ?

Re: pointers and protected objects

[Simon Wright]

tonyg <tonythegair@gmail.com> writes:

> do you know if I separate the body of the protected object in a
> different compilation file and what how I name the file in gnat ?

Yes.

--  pak.ads
package pak is
   protected type p is
      ...
   end p;
end pak;

--  pak.adb
package body pak is
   protected body p is separate;
end pak;

--  pak-p.adb
separate (pak)
protected body p is
   ...
end p;

Re: pointers and protected objects

[AdaMagica]

Am Freitag, 17. Oktober 2014 17:36:54 UTC+2 schrieb Simon Wright:

Note: this naming scheme is GNAT's standard. Other compilers use different schemes.

> --  pak.ads
> package pak is
> end pak;
>
> --  pak.adb
> package body pak is
>    protected body p is separate;
> end pak;
>
> --  pak-p.adb
> separate (pak)
> protected body p is
> end p;

Re: pointers and protected objects

[Adam Beneschan]

On Friday, October 17, 2014 5:51:43 AM UTC-7, tonyg wrote:
> I can create pointers to protected objects, but how do I initialise the protected object as it is a limited type and the syntax
> 
> po_ptr := new Po_Type'(Po_Type_Instance) would not be allowed

That syntax would mean that a new protected object would be created and Po_Type_Instance would be copied to it.  But you can't copy protected objects.  

You can, however, say

    po_ptr := new Po_Type;

or

    po_ptr := new Po_Type'(Some_Function(...));

where Some_Function is a function that returns a Po_Type.

                                -- Adam

Re: pointers and protected objects

[tonyg]

Thanks for your help all :)