Re: [boost] [Review:Algorithms] all.hpp vs std::count

Subject: Re: [boost] [Review:Algorithms] all.hpp vs std::count
From: Marshall Clow (mclow.lists_at_[hidden])
Date: 2011-10-04 20:00:46

On Oct 4, 2011, at 4:42 PM, Stephan T. Lavavej wrote:

> [Dave Abrahams]
>> Furthermore, the size() operation on std::list is not (necessarily) O(1).
> 
> FDIS 23.2.1 [container.requirements.general] requires a.size() to have constant complexity.
> 23.3.5 [list] doesn't specify any exceptions to this. 
> 23.3.4.1 [forwardlist.overview]/2 does: "A forward_list satisfies all of the requirements of a container (Table 96), except that the size() member function is not provided."
> 
> This was changed from C++03, which specified that size() "should have constant complexity".

That's fine - if you are talking about an entire container.
However, for an arbitrary pair of iterators, it is not true.

-- Marshall

Marshall Clow     Idio Software   <mailto:mclow.lists_at_[hidden]>

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