Re: [boost] [Review] Phoenix review starts today, September 21st

Subject: Re: [boost] [Review] Phoenix review starts today, September 21st
From: David Abrahams (dave_at_[hidden])
Date: 2008-09-22 21:49:24

on Mon Sep 22 2008, Joel de Guzman <joel-AT-boost-consulting.com> wrote:

> David Abrahams wrote:
>> on Mon Sep 22 2008, "Peter Dimov" <pdimov-AT-pdimov.com> wrote:
>>
>>> Mathias Gaunard:
>>>> Loïc Joly wrote:
>>>>
>>>>> - How does this library position itself wrt the upcomming C++0x > standard,
>>>> with native support for lambdas, and standardized support for > function or
>>>> bind? Is it more expressive?
>>>>
>>>> The C++0x standard only specifies monomorphic lambdas at the moment.
>>>> So Phoenix is indeed more expressive, since all expressions are polymorphic.
>>> Except phoenix::bind, which is monomorphic, for whatever reasons. :-)
>>>
>>>
> http://www.boost.org/doc/libs/1_36_0/libs/spirit/phoenix/doc/html/phoenix/composite.html#phoenix.composite.bind>
>> Hmm, that seems like it will needlessly restrict generic code.
>
> Ah that one. I think that needs clarification. The note is wrong
> and should be corrected. A bound function pointer or member function
> pointer is only monorphic once bound (of course -- a single function
> pointer or member function pointer is monomorphic). The same is true
> with bind and lambda bind.

Yeah, but what about a bound polymorphic function object?  The doc makes
it sound like passing through bind removes that polymorphism.

> Phoenix bind, like bind and lambda bind is polymorphic at the call
> site in the sense that it can bind to any function and function
> pointer and function object (which can be polymorphic). One problem
> I notice now with the bind documentation of phoenix is that it
> lacks the function object binding part.
>
> Noted for correction. Pardon the confusion.

I'm still confused ;-)

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com