[Boost-bugs] [Boost C++ Libraries] #7226: relax() in relax.hpp can return false even if predecessor map is changed

Subject: [Boost-bugs] [Boost C++ Libraries] #7226: relax() in relax.hpp can return false even if predecessor map is changed
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-08-13 13:54:14

#7226: relax() in relax.hpp can return false even if predecessor map is changed
-------------------------------------------------+--------------------------
 Reporter:  Alex Hagen-Zanker <ahh34@…>          |       Owner:  jewillco
     Type:  Bugs                                 |      Status:  new     
Milestone:  To Be Determined                     |   Component:  graph   
  Version:  Boost 1.51.0                         |    Severity:  Problem 
 Keywords:  relax, floating point precision      |  
-------------------------------------------------+--------------------------
 The relax function in relax.hpp checks whether the distance of an edge
 really is reduced after relaxation and only returns true if that is the
 case. (the alternative possibility is that the expected reduction in
 distance does not take place due to floating point precision).

 However, the function updates the predecessor map in any case. It is
 therefore possible that the predecessor map is changed while the relax
 function returns false. I suppose this is a bug, even though I did not
 cause me any trouble.

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Ticket URL: <https://svn.boost.org/trac/boost/ticket/7226>
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