Re: Ada.Containers.Indefinite_Holders in GNAT and Ada2012

[Victor Porton <porton@narod.ru>]

Victor Porton wrote:

> Victor Porton wrote:
> 
>> I tried to write:
>> 
>> Element(Object)'Access;
>> 
>> for "Object" being a value of an instance of
>> Ada.Containers.Indefinite_Holders.
>> 
>> This does not work because the return type of Element is not aliased.
> 
> By the way, does it makes sense in the next Ada specification to make the
> return type of "Element" function aliased?

Hm, my idea was wrong: Element may return a copy instead of the actual 
element.

However I propose to add Element_Access to next RM which would return access 
to the element in the container.

One (real World!) usage for this: Interfaces.C.Strings.To_Chars_Ptr applied 
to an element in an indefinite holder of type char_array.

>> Then I tried:
>> 
>> Reference(Object).all'Access;
>> 
>> This does not work because in GNAT 4.9 a-coinho.ads source file is not up
>> to date with Ada2012 and there are no Reference function here.
>> 
>> My questions:
>> 
>> 1. How long to wait for GNAT to work with this? (in which GNAT version?)
>> 
>> 2. In a conforming Ada2012 compiler `Reference(Object).all'Access;` is
>> semantically correct, isn't it?
>> 
>> In the meantime, I need to write for my private use a container similar
>> to Ada.Containers.Indefinite_Holders for aliased objects by myself :-(

-- 
Victor Porton - http://portonvictor.org