Re: [Boost-bugs] [Boost C++ Libraries] #7294: boost::hash does not compile with ranges

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7294: boost::hash does not compile with ranges
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-08-27 08:52:24

#7294: boost::hash does not compile with ranges
-----------------------------------------------+----------------------------
  Reporter:  Gennady  Proskurin <gpr@…>        |       Owner:  neilgroves
      Type:  Feature Requests                  |      Status:  new       
 Milestone:  To Be Determined                  |   Component:  range     
   Version:  Boost 1.51.0                      |    Severity:  Problem   
Resolution:                                    |    Keywords:            
-----------------------------------------------+----------------------------
Changes (by danieljames):

  * owner:  danieljames => neilgroves
  * type:  Bugs => Feature Requests
  * component:  hash => range

Comment:

 That's a bug fix, iterator_range has an implicit conversion to bool, which
 is why is was hashing - you really don't want that because it will only
 hash to 0 or 1. So it might have worked, but you get terrible performance
 for more than a few items.

 If you want hashing support for `iterator_range` it will need to be added
 to that library. For an example of how to do that, open boost/array.hpp
 and search for 'hash'. It shouldn't be too hard to implement.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7294#comment:3>
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