Re: point by point advantages of Ada

["Warren W. Gay VE3WWG" <ve3wwg@cogeco.ca>]

Randy Brukardt wrote:
> James S. Rogers wrote in message ...
> 
>>"David Thompson" <david.thompson1@worldnet.att.net> wrote in message
>>news:24oS9.30853$p_6.2594702@bgtnsc04-news.ops.worldnet.att.net...
>>
>>>Ada uses return type to resolve overloading (at compile time), but
>>>not to dispatch (possibly at run time).  (C++ and Java do neither.)
>>
>>Quoting from "Ada as a Second Language" by Cohen:
>>"If a primitive function of a type T has a result of type T, but no
> 
> parameters
> 
>>of type T or access T, a call on the function can be either
> 
> nondispatching or
> 
>>dispatching depending on the context."
>>
>>This is clearly more than simple overload resolution.
> 
> But it's not quite dispatching on the tag of the result (which you can't
> know). But it is dispatching on the tag of result that you need. Here is
> a quick example of it:  <snip>

I thought that this might work:

    declare
       V : T'Class := ...
    begin
       ...
       V := Some_Other_Func;  - Dispatching
    end;

But GNAT (at least) reports that this assignment is "ambiguous"
and will not compile it. I would have expected that it would
resolve it at runtime, knowing the current value of V and its
current tag. Is this consistent with the LRM (IANAL)?
-- 
Warren W. Gay VE3WWG
http://home.cogeco.ca/~ve3wwg