[boost] [range_ex] needs ADL Barrier

From: MB (mb2act_at_[hidden])
Date: 2005-11-29 14:28:02

Hi, gurus,

If boost iterators are passed to 'std::equal' of VC++7.1,
the 'std::equal' calls 'non-qualified' 'mismatch' and
the unintentional ADLookup to 'namespace boost' 
finds incorrectly 'boost::mismatch' of range_ex.

error C2039:
  'const_iterator' : is not a member of 'boost::counting_iterator<Incrementable>'
  // He views iterator as range.

  #include <algorithm>
  #include <vector>
  #include <boost/iterator/counting_iterator.hpp>
  #include <boost/range_ex/algorithm.hpp> // greetings.

  int main()
  {
    std::vector<int> vec;

    std::equal(boost::counting_iterator<int>(0),
      boost::counting_iterator<int>(10), vec.begin());
    return 0;
  }

The workaround is something like:

  namespace boost_range_ex_unspecified {
    // many range algorithms here
    // ...
  }

  namespace boost {
    using namespace boost_range_ex_unspecified;
  }

Regards,
MB
http://p-stade.sourceforge.net/

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