ceph/src/boost/boost/gil/extension/toolbox/metafunctions/get_num_bits.hpp

   1 //
   2 // Copyright 2012 Christian Henning, Andreas Pokorny, Lubomir Bourdev
   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 #ifndef BOOST_GIL_EXTENSION_TOOLBOX_METAFUNCTIONS_GET_NUM_BITS_HPP
   9 #define BOOST_GIL_EXTENSION_TOOLBOX_METAFUNCTIONS_GET_NUM_BITS_HPP
  10
  11 #include <boost/gil/channel.hpp>
  12 #include <boost/gil/detail/is_channel_integral.hpp>
  13 #include <boost/gil/detail/mp11.hpp>
  14
  15 #include <type_traits>
  16
  17 namespace boost{ namespace gil {
  18
  19 /// get_num_bits metafunctions
  20 /// \brief Determines the numbers of bits for the given channel type.
  21
  22 template <typename T, class = void>
  23 struct get_num_bits;
  24
  25 template<typename B, int I, int S, bool M>
  26 struct get_num_bits<packed_channel_reference<B, I, S, M>>
  27     : std::integral_constant<int, S>
  28 {};
  29
  30 template<typename B, int I, int S, bool M>
  31 struct get_num_bits<packed_channel_reference<B, I, S, M> const>
  32     : std::integral_constant<int, S>
  33 {};
  34
  35 template<typename B, int I, bool M>
  36 struct get_num_bits<packed_dynamic_channel_reference<B, I, M>>
  37     : std::integral_constant<int, I>
  38 {};
  39
  40 template<typename B, int I, bool M>
  41 struct get_num_bits<packed_dynamic_channel_reference<B, I, M> const>
  42     : std::integral_constant<int, I>
  43 {};
  44
  45 template<int N>
  46 struct get_num_bits<packed_channel_value<N>> : std::integral_constant<int, N>
  47 {};
  48
  49 template<int N>
  50 struct get_num_bits<packed_channel_value<N> const> : std::integral_constant<int, N>
  51 {};
  52
  53 template <typename T>
  54 struct get_num_bits
  55     <
  56         T,
  57         typename std::enable_if
  58         <
  59             mp11::mp_and
  60             <
  61                 detail::is_channel_integral<T>,
  62                 mp11::mp_not<std::is_class<T>>
  63            >::value
  64        >::type
  65     >
  66     : std::integral_constant<std::size_t, sizeof(T) * 8>
  67 {};
  68
  69 }} // namespace boost::gil
  70
  71 #endif