Re: [Boost-bugs] [Boost C++ Libraries] #6278: mem_fn has a different result_type

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #6278: mem_fn has a different result_type
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-12-16 18:50:07

#6278: mem_fn has a different result_type
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  Reporter:  giecrilj@…             |       Owner:  pdimov 
      Type:  Bugs                   |      Status:  new    
 Milestone:  To Be Determined       |   Component:  bind   
   Version:  Boost 1.48.0           |    Severity:  Problem
Resolution:                         |    Keywords:         
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Comment (by giecrilj@…):

 If result_type were plain, as it ''allegedly'' is, and the type of the
 member were noncopyable then returning it from a function would be a
 problem.

 Specific problem:
   * you cannot copy into a `transform_iterator` when the transform selects
 a reference to a member by means of `mem_fn`.

 If I may digress a bit, I suppose that the reason why the standard does
 not provide an analogue for `mem_fun_ref` for data members is that
 accessing data members is discouraged in C++.  Having come to that
 conclusion, I added the necessary accessors to the underlying class and
 used just `mem_fun_ref`, eradicating `mem_fn` completely.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6278#comment:3>
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