src/gallium/state_trackers/clover/util/tuple.hpp

   1 //
   2 // Copyright 2013 Francisco Jerez
   3 //
   4 // Permission is hereby granted, free of charge, to any person obtaining a
   5 // copy of this software and associated documentation files (the "Software"),
   6 // to deal in the Software without restriction, including without limitation
   7 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 // and/or sell copies of the Software, and to permit persons to whom the
   9 // Software is furnished to do so, subject to the following conditions:
  10 //
  11 // The above copyright notice and this permission notice shall be included in
  12 // all copies or substantial portions of the Software.
  13 //
  14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18 // OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20 // OTHER DEALINGS IN THE SOFTWARE.
  21 //
  22
  23 #ifndef CLOVER_UTIL_TUPLE_HPP
  24 #define CLOVER_UTIL_TUPLE_HPP
  25
  26 #include <tuple>
  27
  28 namespace clover {
  29    namespace tuple {
  30       ///
  31       /// Static sequence of integers.
  32       ///
  33       template<int... Is>
  34       struct integral_sequence;
  35
  36       ///
  37       /// Static sequence containing all integers from 0 to N-1.
  38       ///
  39       template<int N, int... Is>
  40       struct enumerate {
  41          typedef typename enumerate<N-1, N-1, Is...>::type
  42             type;
  43       };
  44
  45       template<int... Is>
  46       struct enumerate<0, Is...> {
  47          typedef integral_sequence<Is...> type;
  48       };
  49
  50       namespace detail {
  51          template<typename F, typename T,
  52                   typename E = typename enumerate<std::tuple_size<
  53                         typename std::remove_reference<T>::type>::value
  54                      >::type>
  55          struct _apply;
  56
  57          template<typename F, typename T, int... Is>
  58          struct _apply<F, T, integral_sequence<Is...>> {
  59             typedef typename std::remove_reference<F>::type func_type;
  60             typedef decltype(
  61                std::declval<func_type>()(std::get<Is>(std::declval<T &&>())...)
  62                ) value_type;
  63
  64             static value_type
  65                eval(F &&f, T &&t) {
  66                return f(std::get<Is>(std::forward<T>(t))...);
  67             }
  68          };
  69       }
  70
  71       ///
  72       /// Evaluate function \a f with the elements of tuple \a t
  73       /// expanded as arguments.
  74       ///
  75       template<typename F, typename T>
  76       typename detail::_apply<F, T>::value_type
  77       apply(F &&f, T &&t) {
  78          return detail::_apply<F, T>::eval(std::forward<F>(f),
  79                                            std::forward<T>(t));
  80       }
  81
  82       namespace detail {
  83          template<typename F, typename T,
  84                   typename E = typename enumerate<std::tuple_size<
  85                         typename std::remove_reference<T>::type>::value
  86                      >::type>
  87          struct _map;
  88
  89          template<typename F, typename T, int... Is>
  90          struct _map<F, T, integral_sequence<Is...>> {
  91             typedef typename std::remove_reference<F>::type func_type;
  92             typedef std::tuple<
  93                decltype(std::declval<func_type>()(
  94                            std::get<Is>(std::declval<T &&>())))...
  95                > value_type;
  96
  97             static value_type
  98                eval(F &&f, T &&t) {
  99                return value_type(f(std::get<Is>(std::forward<T>(t)))...);
 100             }
 101          };
 102       }
 103
 104       ///
 105       /// Evaluate function \a f on each element of the tuple \a t and
 106       /// return the resulting values as a new tuple.
 107       ///
 108       template<typename F, typename T>
 109       typename detail::_map<F, T>::value_type
 110       map(F &&f, T &&t) {
 111          return detail::_map<F, T>::eval(std::forward<F>(f),
 112                                          std::forward<T>(t));
 113       }
 114    }
 115 }
 116
 117 #endif