Boost C++ Libraries

namespace boost {
  namespace algorithm {
    template<typename ForwardIterator1, typename ForwardIterator2, 
             typename BinaryPredicate> 
      bool is_permutation(ForwardIterator1, ForwardIterator1, 
                          ForwardIterator2, BinaryPredicate);
    template<typename ForwardIterator1, typename ForwardIterator2> 
      bool is_permutation(ForwardIterator1, ForwardIterator1, 
                          ForwardIterator2);
    template<typename Range, typename ForwardIterator> 
      bool is_permutation(const Range &, ForwardIterator);
    template<typename Range, typename ForwardIterator, 
             typename BinaryPredicate> 
      boost::disable_if_c< boost::is_same< Range, ForwardIterator >::value, bool >::type 
      is_permutation(const Range &, ForwardIterator, BinaryPredicate);
  }
}