ceph/src/boost/libs/icl/include/boost/icl/type_traits/succ_pred.hpp

   1 /*-----------------------------------------------------------------------------+
   2 Copyright (c) 2008-2011: Joachim Faulhaber
   3 +------------------------------------------------------------------------------+
   4    Distributed under the Boost Software License, Version 1.0.
   5       (See accompanying file LICENCE.txt or copy at
   6            http://www.boost.org/LICENSE_1_0.txt)
   7 +-----------------------------------------------------------------------------*/
   8 #ifndef BOOST_ICL_TYPE_TRAITS_SUCC_PRED_HPP_JOFA_080913
   9 #define BOOST_ICL_TYPE_TRAITS_SUCC_PRED_HPP_JOFA_080913
  10
  11 #include <boost/icl/type_traits/is_increasing.hpp>
  12
  13 namespace boost{ namespace icl
  14 {
  15 template <class IncrementableT>
  16 inline static IncrementableT succ(IncrementableT x) { return ++x; }
  17
  18 template <class DecrementableT>
  19 inline static DecrementableT pred(DecrementableT x) { return --x; }
  20
  21 namespace detail
  22 {
  23     template <class DomainT, bool increasing = true>
  24     struct successor;
  25
  26     template <class DomainT>
  27     struct successor<DomainT, true>
  28     {
  29         typedef successor type;
  30         inline static DomainT apply(DomainT value){ return ++value; }
  31     };
  32
  33     template <class DomainT>
  34     struct successor<DomainT, false>
  35     {
  36         typedef successor type;
  37         inline static DomainT apply(DomainT value){ return --value; }
  38     };
  39
  40     template <class DomainT, bool increasing = true>
  41     struct predecessor;
  42
  43     template <class DomainT>
  44     struct predecessor<DomainT, true>
  45     {
  46         typedef predecessor type;
  47         inline static DomainT apply(DomainT value){ return --value; }
  48     };
  49
  50     template <class DomainT>
  51     struct predecessor<DomainT, false>
  52     {
  53         typedef predecessor type;
  54         inline static DomainT apply(DomainT value){ return ++value; }
  55     };
  56 } // namespace detail
  57
  58 //------------------------------------------------------------------------------
  59 template <class DomainT, class Compare>
  60 struct successor
  61 {
  62     inline static DomainT apply(DomainT value)
  63     {
  64         return detail::successor
  65             <DomainT, is_increasing<DomainT,Compare>::value>::apply(value);
  66     }
  67 };
  68
  69 template <class DomainT, class Compare>
  70 struct predecessor
  71 {
  72     inline static DomainT apply(DomainT value)
  73     {
  74         return detail::predecessor
  75             <DomainT, is_increasing<DomainT,Compare>::value>::apply(value);
  76     }
  77 };
  78
  79 }} // namespace boost icl
  80
  81 #endif
  82
  83