Re: [boost] Formal Review Request: TypeErasure

Subject: Re: [boost] Formal Review Request: TypeErasure
From: Julien Nitard (julien.nitard_at_[hidden])
Date: 2012-06-14 09:51:08

Hi again,

On Thu, Jun 14, 2012 at 2:45 AM, Dave Abrahams <dave_at_[hidden]>

[...]

>
>> Moreover, when using polymorphic value types implemented this way, you
>> are still paying for one dynamic allocation and one deletion per copy
>> of the object (this may be implementation–specific). Since those
>> objects are supposed to be copied frequently,
>
> Says who?

Well, if you go all that way to have polymorphism on value types and
you take references to them, I fail to see why you did the effort in
the first place. You actually said:

>>> and => reference semantics  (- hard to reason about)

I am probably missing the point, but I am not sure where.

> Of course.  And I don't want to avoid shared state completely.  I want
> to avoid sharing state all over the place "by default."  By the way,
> this affects single-threaded code too.  If you haven't heard of
> "defensive copying" in the Java world, look it up.

I'll be doing that, many thanks for the advice.

Julien