is_homogeneous.hpp 2.8 KB

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