ceph/src/boost/libs/accumulators/include/boost/accumulators/statistics/times2_iterator.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // times2_iterator.hpp
   3 //
   4 //  Copyright 2006 Eric Niebler. Distributed under the Boost
   5 //  Software License, Version 1.0. (See accompanying file
   6 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7
   8 #ifndef BOOST_ACCUMULATORS_STATISTICS_TIMES2_ITERATOR_HPP_DE_01_01_2006
   9 #define BOOST_ACCUMULATORS_STATISTICS_TIMES2_ITERATOR_HPP_DE_01_01_2006
  10
  11 #include <functional>
  12 #include <boost/detail/workaround.hpp>
  13 #include <boost/range/begin.hpp>
  14 #include <boost/range/end.hpp>
  15 #include <boost/range/iterator_range.hpp>
  16 #include <boost/iterator/transform_iterator.hpp>
  17 #include <boost/iterator/counting_iterator.hpp>
  18 #include <boost/iterator/permutation_iterator.hpp>
  19
  20 namespace boost { namespace accumulators
  21 {
  22
  23 namespace detail
  24 {
  25     typedef transform_iterator<
  26         std::binder1st<std::multiplies<std::size_t> >
  27       , counting_iterator<std::size_t>
  28     > times2_iterator;
  29
  30     inline times2_iterator make_times2_iterator(std::size_t i)
  31     {
  32         return make_transform_iterator(
  33             make_counting_iterator(i)
  34           , std::bind1st(std::multiplies<std::size_t>(), 2)
  35         );
  36     }
  37
  38     ///////////////////////////////////////////////////////////////////////////////
  39     // lvalue_index_iterator
  40     template<typename Base>
  41     struct lvalue_index_iterator
  42       : Base
  43     {
  44         lvalue_index_iterator()
  45           : Base()
  46         {}
  47
  48         lvalue_index_iterator(Base base)
  49           : Base(base)
  50         {
  51         }
  52
  53         typename Base::reference operator [](typename Base::difference_type n) const
  54         {
  55             return *(*this + n);
  56         }
  57     };
  58 } // namespace detail
  59
  60 }}
  61
  62 #endif