[Boost-bugs] [Boost C++ Libraries] #7824: "++--rng.end() == rng.end()" can fail for strided ranges

Subject: [Boost-bugs] [Boost C++ Libraries] #7824: "++--rng.end() == rng.end()" can fail for strided ranges
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-12-22 07:53:10

#7824: "++--rng.end() == rng.end()" can fail for strided ranges
-------------------------------------+--------------------------------------
 Reporter:  michel                   |       Owner:  neilgroves
     Type:  Bugs                     |      Status:  new       
Milestone:  To Be Determined         |   Component:  range     
  Version:  Boost Development Trunk  |    Severity:  Problem   
 Keywords:                           |  
-------------------------------------+--------------------------------------
 Attached a test case for which "`++--rng.end() == rng.end()`" fails.

 Due to this bug, libc++'s `deque<T>::insert` function misunderstands
 the size of strided ranges. For example,
 {{{
 using boost::strided_range;
 using boost::adaptors::strided;

 int ar[3] = {0, 1, 2};
 strided_range<int[3]> rng = ar | strided(3);

 std::deque<int> cont;
 cont.insert(cont.begin(), rng.begin(), rng.end());

 std::cout << cont.size() << std::endl;
 }}}
 outputs 2 (not 1) with libc++.
 You can see `libs/range/test/adaptor_test/strided.cpp` fails
 on test runners with libc++.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7824>
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