Re: [Boost-bugs] [Boost C++ Libraries] #1519: lvalue-ness resurrection in transform_iterator

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #1519: lvalue-ness resurrection in transform_iterator
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-06-06 15:39:25

#1519: lvalue-ness resurrection in transform_iterator
----------------------------------------------------+-----------------------
  Reporter:  Shunsuke Sogame <pstade.mb@…>          |       Owner:  dave                       
      Type:  Patches                                |      Status:  closed                     
 Milestone:  Boost 1.36.0                           |   Component:  iterator                   
   Version:  Boost Development Trunk                |    Severity:  Problem                    
Resolution:  invalid                                |    Keywords:  transform_iterator iterator
----------------------------------------------------+-----------------------
Changes (by dave):

  * status:  new => closed
  * resolution:  => invalid

Comment:

 If I understand correctly what your patch is doing, you are effectively
 determining whether the resulting {{{transform_iterator<...>}}} satisfies
 the access requirements of !ForwardIterator (and thus,
 !RandomAccessIterator) by looking at the lvalueness of the transformed
 result_type.  Unfortunately, that's not a valid way to make the
 determination, because the resulting iterator doesn't suddenly become
 multipass just because of a change in the reference type. In fact, most of
 the standard's !InputIterators return references from their
 {{{operator*}}}.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/1519#comment:1>
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