Re: [boost] AlRangeExandrescu?

Subject: Re: [boost] AlRangeExandrescu?
From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2009-07-26 03:59:05

Thorsten Ottosen skrev:
> Andrei Alexandrescu skrev:
>> Thorsten Ottosen wrote:
> 
>>> A "not" slipped here.
>>>
>>>> Yes, until is lazy. I think it couldn't be implemented any other way 
>>>> for input ranges.
>>>
>>> Ok, but the problem with lazy ranges is that when you compose it with
>>> range adaptors, then it greatly limits the adaptors that you can 
>>> subsequently apply.
>>
>> Why is that the case?
> 
> because some adapters require random aceesss ranges e.g.
> 
>  rng | stride_view
> 
> and some requires bidirectionsal ranges e.g.
> 
>  rng | reverse_view

And also many later operations are usually more efficient when e.g. 
random access is preserved.

-Thorsten