ceph/src/boost/libs/range/include/boost/range/size_type.hpp

   1 // Boost.Range library
   2 //
   3 //  Copyright Thorsten Ottosen 2003-2004. Use, modification and
   4 //  distribution is subject to the Boost Software License, Version
   5 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
   6 //  http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // For more information, see http://www.boost.org/libs/range/
   9 //
  10
  11 #ifndef BOOST_RANGE_SIZE_TYPE_HPP
  12 #define BOOST_RANGE_SIZE_TYPE_HPP
  13
  14 #if defined(_MSC_VER)
  15 # pragma once
  16 #endif
  17
  18 #include <boost/range/config.hpp>
  19 #include <boost/range/difference_type.hpp>
  20 #include <boost/range/concepts.hpp>
  21 #include <boost/range/has_range_iterator.hpp>
  22
  23 #include <boost/utility/enable_if.hpp>
  24 #include <boost/type_traits/make_unsigned.hpp>
  25 #include <boost/type_traits/remove_const.hpp>
  26 #include <cstddef>
  27 #include <utility>
  28
  29 namespace boost
  30 {
  31     namespace detail
  32     {
  33
  34         //////////////////////////////////////////////////////////////////////////
  35         // default
  36         //////////////////////////////////////////////////////////////////////////
  37
  38         template<typename T>
  39         class has_size_type
  40         {
  41             typedef char no_type;
  42             struct yes_type { char dummy[2]; };
  43
  44             template<typename C>
  45             static yes_type test(BOOST_DEDUCED_TYPENAME C::size_type x);
  46
  47             template<typename C>
  48             static no_type test(...);
  49
  50         public:
  51             static const bool value = sizeof(test<T>(0)) == sizeof(yes_type);
  52         };
  53
  54         template<typename C, typename Enabler=void>
  55         struct range_size_
  56         {
  57             typedef BOOST_DEDUCED_TYPENAME make_unsigned<
  58                 BOOST_DEDUCED_TYPENAME range_difference<C>::type
  59             >::type type;
  60         };
  61
  62         template<typename C>
  63         struct range_size_<
  64             C,
  65             BOOST_DEDUCED_TYPENAME ::boost::enable_if<has_size_type<C>, void>::type
  66         >
  67         {
  68             typedef BOOST_DEDUCED_TYPENAME C::size_type type;
  69         };
  70
  71         template<typename C, bool B = range_detail::has_type< range_iterator<C> >::value>
  72         struct range_size
  73         { };
  74
  75         template<typename C>
  76         struct range_size<C, true>
  77           : range_size_<C>
  78         { };
  79     }
  80
  81     template< class T >
  82     struct range_size :
  83         detail::range_size<T>
  84     { };
  85
  86     template< class T >
  87     struct range_size<const T > :
  88         detail::range_size<T>
  89     { };
  90
  91 } // namespace boost
  92
  93
  94
  95 #endif