ceph/src/boost/libs/compute/include/boost/compute/functional/detail/unpack.hpp

   1 //---------------------------------------------------------------------------//
   2 // Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 // See http://boostorg.github.com/compute for more information.
   9 //---------------------------------------------------------------------------//
  10
  11 #ifndef BOOST_COMPUTE_FUNCTIONAL_DETAIL_UNPACK_HPP
  12 #define BOOST_COMPUTE_FUNCTIONAL_DETAIL_UNPACK_HPP
  13
  14 #include <boost/compute/functional/get.hpp>
  15 #include <boost/compute/type_traits/is_vector_type.hpp>
  16 #include <boost/compute/type_traits/result_of.hpp>
  17 #include <boost/compute/type_traits/vector_size.hpp>
  18 #include <boost/compute/detail/meta_kernel.hpp>
  19
  20 namespace boost {
  21 namespace compute {
  22 namespace detail {
  23
  24 template<class Function, class Arg, size_t Arity>
  25 struct invoked_unpacked
  26 {
  27     invoked_unpacked(const Function &f, const Arg &arg)
  28         : m_function(f),
  29           m_arg(arg)
  30     {
  31     }
  32
  33     Function m_function;
  34     Arg m_arg;
  35 };
  36
  37 template<class Function, class Arg, size_t Arity>
  38 inline meta_kernel& operator<<(meta_kernel &k, const invoked_unpacked<Function, Arg, Arity> &expr);
  39
  40 template<class Function, class Arg>
  41 inline meta_kernel& operator<<(meta_kernel &k, const invoked_unpacked<Function, Arg, 1> &expr)
  42 {
  43     return k << expr.m_function(get<0>()(expr.m_arg));
  44 }
  45
  46 template<class Function, class Arg>
  47 inline meta_kernel& operator<<(meta_kernel &k, const invoked_unpacked<Function, Arg, 2> &expr)
  48 {
  49     return k << expr.m_function(get<0>()(expr.m_arg), get<1>()(expr.m_arg));
  50 }
  51
  52 template<class Function, class Arg>
  53 inline meta_kernel& operator<<(meta_kernel &k, const invoked_unpacked<Function, Arg, 3> &expr)
  54 {
  55     return k << expr.m_function(get<0>()(expr.m_arg), get<1>()(expr.m_arg), get<2>()(expr.m_arg));
  56 }
  57
  58 template<class Function>
  59 struct unpacked
  60 {
  61     template<class T, class Enable = void>
  62     struct aggregate_length
  63     {
  64         BOOST_STATIC_CONSTANT(size_t, value = boost::tuples::length<T>::value);
  65     };
  66
  67     template<class T>
  68     struct aggregate_length<T, typename enable_if<is_vector_type<T> >::type>
  69     {
  70         BOOST_STATIC_CONSTANT(size_t, value = vector_size<T>::value);
  71     };
  72
  73     template<class TupleArg, size_t TupleSize>
  74     struct result_impl {};
  75
  76     template<class TupleArg>
  77     struct result_impl<TupleArg, 1>
  78     {
  79         typedef typename detail::get_result_type<0, TupleArg>::type T1;
  80
  81         typedef typename boost::compute::result_of<Function(T1)>::type type;
  82     };
  83
  84     template<class TupleArg>
  85     struct result_impl<TupleArg, 2>
  86     {
  87         typedef typename detail::get_result_type<0, TupleArg>::type T1;
  88         typedef typename detail::get_result_type<1, TupleArg>::type T2;
  89
  90         typedef typename boost::compute::result_of<Function(T1, T2)>::type type;
  91     };
  92
  93     template<class TupleArg>
  94     struct result_impl<TupleArg, 3>
  95     {
  96         typedef typename detail::get_result_type<0, TupleArg>::type T1;
  97         typedef typename detail::get_result_type<1, TupleArg>::type T2;
  98         typedef typename detail::get_result_type<2, TupleArg>::type T3;
  99
 100         typedef typename boost::compute::result_of<Function(T1, T2, T3)>::type type;
 101     };
 102
 103     template<class Signature>
 104     struct result {};
 105
 106     template<class This, class Arg>
 107     struct result<This(Arg)>
 108     {
 109         typedef typename result_impl<Arg, aggregate_length<Arg>::value>::type type;
 110     };
 111
 112     unpacked(const Function &f)
 113         : m_function(f)
 114     {
 115     }
 116
 117     template<class Arg>
 118     detail::invoked_unpacked<
 119         Function, Arg, aggregate_length<typename Arg::result_type>::value
 120     >
 121     operator()(const Arg &arg) const
 122     {
 123         return detail::invoked_unpacked<
 124                    Function,
 125                    Arg,
 126                    aggregate_length<typename Arg::result_type>::value
 127                 >(m_function, arg);
 128     }
 129
 130     Function m_function;
 131 };
 132
 133 template<class Function>
 134 inline unpacked<Function> unpack(const Function &f)
 135 {
 136     return unpacked<Function>(f);
 137 }
 138
 139 } // end detail namespace
 140 } // end compute namespace
 141 } // end boost namespace
 142
 143 #endif // BOOST_COMPUTE_FUNCTIONAL_DETAIL_UNPACK_HPP