Old problem with performance

[Don]

Weed wrote:
> Don пишет:
>> Weed wrote:
>>> Christopher Wright пишет:
>>>> Weed wrote:
>>>>> Kagamin пишет:
>>>>>> Weed Wrote:
>>>>>>
>>>>>>> Will the language change?
>>>>>> Hmm... You already has Walter's answer. He's the boss.
>>>>> I want a more specific answer (yes or no) if possible...
>>>> It will not. If you come up with some really awesome use case, then it
>>>> could, but nobody has yet, and the issue comes up every few months.
>>> Good (I think) use cases have been in this thread
>> They have not. The examples have been incomplete. You've provided use
>> cases involving classes, but haven't given _any_ details about the
>> contents of those classes.
>>
>> It's possible that you have indeed found use cases, but you haven't
>> actually shown them here.
> 
> I do not understand the claims.
> 
> For example, any class that implements the mathematical object (matrix,
> vector, number, etc.) is suitable for example. I think it is obvious.

Absolutely not! Those cases involve no polymorphism! No virtual function 
calls.

> Yes, the discussion in this thread showed that almost always possible
> for each case to find a different approach, using additives and other
> scary code. But what if these "perversions" flaw somewhere in the idea
> of a "reference-only" type?
> 
> I understand people who are against the changes of language, as they
> would at least explore these changes. I myself belong to those people, I
> do not like changes associated with cosmetic amenities, breaking the
> old-established solution for years.

I don't think the resistance comes from intertia and committment to the 
"long-established solution". There's plenty of C++ programmers here 
(including myself).

> I also understand the people who came from the languages Java and C#,
> which is not familiar with the semantics of the class value.
> 
> But just such a case, when the inertia hinders the development of
> language and prevents them winning at least a substantial number of
> positions. (Namely: the replacement of old C++. Yes, I believe, without
> C++ replacement functionality D will not be needed.)

> I think the problem is real and requires action. Not sure it will be a
> value semantic. Maybe we come up with something entirely new? I do not know.
> 
> But the problem is that one must at least acknowledge it and not come
> off the common phrases that "your use cases are not serious" etc.

You really MUST start from a solid use case. I'm genuinely surprised 
that you've had so much trouble coming up with one; it suggests to me 
that you're not looking at the right problem.