Re: Problem trying to implement generics.

["Dmitry A. Kazakov" <dmitry@elros.cbb-automation.de>]

James Rogers wrote:

> Ayende Rahien wrote:
> 
>> "Dmitry A. Kazakov" <dmitry@elros.cbb-automation.de> wrote in message
>> news:3AD858A3.3070803@elros.cbb-automation.de...
>> 
>>> Well, but what I still cannot understand, what is the objection against
>>> *procedures* returning a value:
>> 
>> Because that is the difference between functions & procedures?
>> If you wanted it that way, you could do this:
>> function Foo(...) return nothing;
>> 
>> But I agree that it would be nice to be able to ignore function's return
>> value.
> 
> A procedure may modify parameters, but may not return a value.

Why? There are lot of cases where a procedure with a result would be 
natural: random generator, memory allocator, table search etc.

> The practice in C, C++, and Java of ignoring return values from 
> functions or methods may seem very convenient. In fact it is a
> fundamental violation of the contract defined for a function. This
> is the single greatest reason exceptions were added to C++, and
> included from the start in Java. A common C programming paradigm
> is to have a function return an indication of success or failure.
> That same function may also modify some or all parameter values.
> It is also very common in C to ignore the return value of a
> function. What is the obvious problem? If the return value
> indicates success or failure and that value is ignored, then the

The practice is exactly the point. Take a look at Windows API. You will 
discover functions returning values which nobody needs and modifying 
parameters as well as global system state.

Then I absolutely agree with you that ignoring the return value 
indicates a potential problem, therefore I would like to have a syntax 
construct for this, that will alert a code reader. Just like 
"unchecked_access". Moreover, I would like to have some syntax sugar for 
dummy [in]out parameters, but I have no idea how it cold look like.

Regards,
Dmitry Kazakov