Re: Adding functions to generic package

[Marius Amado Alves <amado.alves@netcabo.pt>]

>>> I guess it must be:
>>>
>>>    procedure Swap (Container : in out Container_Type; L,R :
>>> Iterator_Type);
>>
>> No need. Cursors know their containers. (Marius)
>
> No, this is wrong.
>
> In Charles, iterators do *not* carry a pointer to container...
> Mario is probably thinking of the Ada 2005 standard container library. 
> (Matthew)

Yes. Sorry.

> Cursor types do indeed hold a pointer to the container, in addition to
> the node.  However, the rule about manipulation of the container object
> still applies (what a coincidence!), so the container is passed as a
> parameter too (see the operation named Swap_Links).

Ada.Containers has this operation for Lists and Vectors:

procedure Swap (I, J      : in Cursor);

with semantics

"If either I or J is No_Element, then Constraint_Error is propagated. 
If I and J
designate elements in different containers, then Program_Error is 
propagated.
Otherwise Swap exchanges the values of the elements designated by I and 
J."

(cf. http://www.softdevelcoop.org/software/ada_containers)

Is "exchanging values" not "manipulating the container?"