Re: [Boost-bugs] [Boost C++ Libraries] #11769: 64-bit hash_combine has weakness against zero input

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #11769: 64-bit hash_combine has weakness against zero input
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2016-01-13 23:55:34


#11769: 64-bit hash_combine has weakness against zero input
--------------------------------------+-------------------------
  Reporter: andysem | Owner: danieljames
      Type: Bugs | Status: assigned
 Milestone: To Be Determined | Component: hash
   Version: Boost Development Trunk | Severity: Problem
Resolution: | Keywords:
--------------------------------------+-------------------------
Changes (by danieljames):

 * status: new => assigned

Comment:

 You're right about the function but it turns out that there's no real
 problem for an embarrassing reason - that function has a spurious template
 argument so it's never used.

 There are unit tests for this exact problem (in `hash_sequence_test.hpp`),
 and I'm relieved to say that they would have been caught the problem if
 that function was actually used, so at least I got that right.

 I think I'll fix the function and put it to use. I had originally intended
 to do more rigorous testing of hash quality before releasing it, but ended
 up having little time. I think I'll be more cautious this time, so the new
 version might not make it into the next version of boost.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11769#comment:2>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.

This archive was generated by hypermail 2.1.7 : 2017-02-16 18:50:19 UTC