ceph/src/boost/boost/gil/extension/toolbox/metafunctions/is_homogeneous.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_IS_HOMOGENEOUS_HPP
   9 #define BOOST_GIL_EXTENSION_TOOLBOX_METAFUNCTIONS_IS_HOMOGENEOUS_HPP
  10
  11 #include <boost/gil/pixel.hpp>
  12 #include <boost/gil/detail/mp11.hpp>
  13
  14 #include <type_traits>
  15
  16 namespace boost{ namespace gil {
  17
  18 /// is_homogeneous metafunctions
  19 /// \brief Determines if a pixel types are homogeneous.
  20
  21 template<typename C,typename CMP, int Next, int Last>
  22 struct is_homogeneous_impl;
  23
  24 template<typename C, typename CMP, int Last>
  25 struct is_homogeneous_impl<C, CMP, Last, Last> : std::true_type {};
  26
  27 template<typename C, typename CMP, int Next, int Last>
  28 struct is_homogeneous_impl
  29     : mp11::mp_and
  30         <
  31             is_homogeneous_impl<C, CMP, Next + 1, Last>,
  32             std::is_same<CMP, mp11::mp_at_c<C, Next>>
  33         >
  34 {};
  35
  36 template <typename P>
  37 struct is_homogeneous : std::false_type {};
  38
  39 // pixel
  40 template <typename C, typename L>
  41 struct is_homogeneous<pixel<C, L>> : std::true_type {};
  42
  43 template <typename C, typename L >
  44 struct is_homogeneous<pixel<C, L> const> : std::true_type {};
  45
  46 template <typename C, typename L>
  47 struct is_homogeneous<pixel<C, L>&> : std::true_type {};
  48
  49 template <typename C, typename L>
  50 struct is_homogeneous<pixel<C, L> const&> : std::true_type {};
  51
  52 // planar pixel reference
  53 template <typename Channel, typename ColorSpace>
  54 struct is_homogeneous<planar_pixel_reference<Channel, ColorSpace>> : std::true_type {};
  55
  56 template <typename Channel, typename ColorSpace>
  57 struct is_homogeneous<planar_pixel_reference<Channel, ColorSpace> const> : std::true_type {};
  58
  59 template<typename C, typename CMP, int I, int Last>
  60 struct is_homogeneous_impl_p {};
  61
  62 // for packed_pixel
  63 template <typename B, typename C, typename L>
  64 struct is_homogeneous<packed_pixel<B, C, L>>
  65     : is_homogeneous_impl_p
  66     <
  67         C,
  68         mp11::mp_at_c<C, 0>,
  69         1,
  70         mp11::mp_size<C>::value
  71     > {};
  72
  73 template< typename B
  74         , typename C
  75         , typename L
  76         >
  77 struct is_homogeneous<packed_pixel<B, C, L> const>
  78     : is_homogeneous_impl_p
  79     <
  80         C,
  81         mp11::mp_at_c<C, 0>,
  82         1,
  83         mp11::mp_size<C>::value
  84     > {};
  85
  86 // for bit_aligned_pixel_reference
  87 template <typename B, typename C, typename L, bool M>
  88 struct is_homogeneous<bit_aligned_pixel_reference<B, C, L, M>>
  89     : is_homogeneous_impl<C, mp11::mp_at_c<C, 0>, 1, mp11::mp_size<C>::value>
  90 {};
  91
  92 template <typename B, typename C, typename L, bool M>
  93 struct is_homogeneous<const bit_aligned_pixel_reference<B, C, L, M> >
  94     : is_homogeneous_impl<C, mp11::mp_at_c<C, 0>, 1, mp11::mp_size<C>::value>
  95 {};
  96
  97 }} // namespace boost::gil
  98
  99 #endif