boost/gil/concepts/pixel_dereference.hpp

   1 //
   2 // Copyright 2005-2007 Adobe Systems Incorporated
   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_CONCEPTS_PIXEL_DEREFERENCE_HPP
   9 #define BOOST_GIL_CONCEPTS_PIXEL_DEREFERENCE_HPP
  10
  11 #include <boost/gil/concepts/basic.hpp>
  12 #include <boost/gil/concepts/concept_check.hpp>
  13 #include <boost/gil/concepts/fwd.hpp>
  14 #include <boost/gil/concepts/pixel.hpp>
  15 #include <boost/gil/concepts/detail/type_traits.hpp>
  16
  17 #include <boost/concept_check.hpp>
  18
  19 #include <cstddef>
  20 #include <type_traits>
  21
  22 #if defined(BOOST_CLANG)
  23 #pragma clang diagnostic push
  24 #pragma clang diagnostic ignored "-Wunused-local-typedefs"
  25 #endif
  26
  27 #if defined(BOOST_GCC) && (BOOST_GCC >= 40900)
  28 #pragma GCC diagnostic push
  29 #pragma GCC diagnostic ignored "-Wunused-local-typedefs"
  30 #endif
  31
  32 namespace boost { namespace gil {
  33
  34 /// \ingroup PixelDereferenceAdaptorConcept
  35 /// \brief Represents a unary function object that can be invoked upon dereferencing a pixel iterator.
  36 ///
  37 /// This can perform an arbitrary computation, such as color conversion or table lookup.
  38 /// \code
  39 /// concept PixelDereferenceAdaptorConcept<boost::UnaryFunctionConcept D>
  40 ///     : DefaultConstructibleConcept<D>, CopyConstructibleConcept<D>, AssignableConcept<D>
  41 /// {
  42 ///     typename const_t; where PixelDereferenceAdaptorConcept<const_t>;
  43 ///     typename value_type; where PixelValueConcept<value_type>;
  44 ///     typename reference;         // may be mutable
  45 ///     typename const_reference;   // must not be mutable
  46 ///     static const bool D::is_mutable;
  47 ///
  48 ///     where Convertible<value_type,result_type>;
  49 /// };
  50 /// \endcode
  51 template <typename D>
  52 struct PixelDereferenceAdaptorConcept
  53 {
  54     void constraints()
  55     {
  56         gil_function_requires
  57         <
  58             boost::UnaryFunctionConcept
  59             <
  60                 D,
  61                 typename detail::remove_const_and_reference<typename D::result_type>::type,
  62                 typename D::argument_type
  63             >
  64         >();
  65         gil_function_requires<boost::DefaultConstructibleConcept<D>>();
  66         gil_function_requires<boost::CopyConstructibleConcept<D>>();
  67         gil_function_requires<boost::AssignableConcept<D>>();
  68
  69         gil_function_requires<PixelConcept
  70             <
  71                 typename detail::remove_const_and_reference<typename D::result_type>::type
  72             >>();
  73
  74         using const_t = typename D::const_t;
  75         gil_function_requires<PixelDereferenceAdaptorConcept<const_t>>();
  76
  77         using value_type = typename D::value_type;
  78         gil_function_requires<PixelValueConcept<value_type>>();
  79
  80         // TODO: Should this be concept-checked after "if you remove const and reference"? --mloskot
  81         using reference = typename D::reference; // == PixelConcept (if you remove const and reference)
  82         using const_reference = typename D::const_reference; // == PixelConcept (if you remove const and reference)
  83
  84         bool const is_mutable = D::is_mutable;
  85         ignore_unused_variable_warning(is_mutable);
  86     }
  87     D d;
  88 };
  89
  90 template <typename P>
  91 struct PixelDereferenceAdaptorArchetype
  92 {
  93     using argument_type = P;
  94     using result_type = P;
  95     using const_t = PixelDereferenceAdaptorArchetype;
  96     using value_type = typename std::remove_reference<P>::type;
  97     using reference = typename std::add_lvalue_reference<P>::type;
  98     using const_reference = reference;
  99
 100     static const bool is_mutable = false;
 101     P operator()(P) const { throw; }
 102 };
 103
 104 }} // namespace boost::gil
 105
 106 #if defined(BOOST_CLANG)
 107 #pragma clang diagnostic pop
 108 #endif
 109
 110 #if defined(BOOST_GCC) && (BOOST_GCC >= 40900)
 111 #pragma GCC diagnostic pop
 112 #endif
 113
 114 #endif