Re: [Boost-bugs] [Boost C++ Libraries] #6095: boost::icl::is_empty fails for certain open intervals

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #6095: boost::icl::is_empty fails for certain open intervals
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-11-06 16:53:22

#6095: boost::icl::is_empty fails for certain open intervals
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  Reporter:  Marvin Sielenkemper <m.sielenkemper@…>             |       Owner:  jofaber
      Type:  Bugs                                               |      Status:  new    
 Milestone:  To Be Determined                                   |   Component:  ICL    
   Version:  Boost 1.47.0                                       |    Severity:  Problem
Resolution:                                                     |    Keywords:         
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Comment (by jofaber):

 Hi Marvin,

 thank you for your report and the attached patch. I agree that the
 behavior of {{{icl::intervals}}} at open borders and for limited domain
 types is kind of nasty. Nevertheless after examining your information I am
 not convinced that we can speak of a bug here and that a code change is
 needed.

 In your test case you propose that
 {{{
   BOOST_CHECK( is_empty(Interval::open(max, max)));
 }}}

 is supposed to succeed. But an open interval {{{Interval::open(max, x)}}}
 has an open lower bound of {{{max}}}, which means that values of its
 domain_type do not exist that can be elements of the interval. My
 interpretation of intervals of this kind is that they are ill formed
 rather than empty. So the user has to take care via program logic that
 these types of intervals are not constructed in the same way she has to
 take care that {{{++i}}} is not called if {{{i ==
 numeric_limits<int>::max()}}} already.

 Best regards,
 Joachim

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/6095#comment:1>
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