[boost] Re: boost::transform_iterator and boost::lambda functors

From: David Abrahams (dave_at_[hidden])
Date: 2004-06-10 16:21:48

"Peter Dimov" <pdimov_at_[hidden]> writes:

> David Abrahams wrote:
>> "Maxim Yegorushkin" <e-maxim_at_[hidden]> writes:
>>
>>> David Abrahams <dave_at_[hidden]> wrote:
>>>
>>> I wonder, why doesn't boost::lambda::ret<> privide that functionality
>>> of boost::make_adaptable<>? It would certainly made sense and saved
>>> me and hopefully other people from troubles.
>>
>> It can't.  The result type of the lambda expression depends on its
>> inputs.  result_type is only one type.  Adaptable functions are
>> fundamentally non-polymorphic.
>
> The result type of ret<R>(expr) is always R. That's what it does. That's
> _all_ it does. ;-)

Sorry, I thought it was something else.

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com