github.com/kaydxh/golang@v0.0.131/pkg/gocv/cgo/third_path/opencv4/include/opencv2/gapi/util/util.hpp (about)

     1  // This file is part of OpenCV project.
     2  // It is subject to the license terms in the LICENSE file found in the top-level directory
     3  // of this distribution and at http://opencv.org/license.html.
     4  //
     5  // Copyright (C) 2018-2019 Intel Corporation
     6  
     7  
     8  #ifndef OPENCV_GAPI_UTIL_HPP
     9  #define OPENCV_GAPI_UTIL_HPP
    10  
    11  #include <tuple>
    12  
    13  // \cond HIDDEN_SYMBOLS
    14  // This header file contains some generic utility functions which are
    15  // used in other G-API Public API headers.
    16  //
    17  // PLEASE don't put any stuff here if it is NOT used in public API headers!
    18  
    19  namespace cv
    20  {
    21  namespace detail
    22  {
    23      // Recursive integer sequence type, useful for enumerating elements of
    24      // template parameter packs.
    25      template<int... I> struct Seq     { using next = Seq<I..., sizeof...(I)>; };
    26      template<int Sz>   struct MkSeq   { using type = typename MkSeq<Sz-1>::type::next; };
    27      template<>         struct MkSeq<0>{ using type = Seq<>; };
    28  
    29      // Checks if elements of variadic template satisfy the given Predicate.
    30      // Implemented via tuple, with an interface to accept plain type lists
    31      template<template<class> class, typename, typename...> struct all_satisfy;
    32  
    33      template<template<class> class F, typename T, typename... Ts>
    34      struct all_satisfy<F, std::tuple<T, Ts...> >
    35      {
    36          static const constexpr bool value = F<T>::value
    37              && all_satisfy<F, std::tuple<Ts...> >::value;
    38      };
    39      template<template<class> class F, typename T>
    40      struct all_satisfy<F, std::tuple<T> >
    41      {
    42          static const constexpr bool value = F<T>::value;
    43      };
    44  
    45      template<template<class> class F, typename T, typename... Ts>
    46      struct all_satisfy: public all_satisfy<F, std::tuple<T, Ts...> > {};
    47  
    48      // Permute given tuple type C with given integer sequence II
    49      // Sequence may be less than tuple C size.
    50      template<class, class> struct permute_tuple;
    51  
    52      template<class C, int... IIs>
    53      struct permute_tuple<C, Seq<IIs...> >
    54      {
    55          using type = std::tuple< typename std::tuple_element<IIs, C>::type... >;
    56      };
    57  
    58      // Given T..., generates a type sequence of sizeof...(T)-1 elements
    59      // which is T... without its last element
    60      // Implemented via tuple, with an interface to accept plain type lists
    61      template<typename T, typename... Ts> struct all_but_last;
    62  
    63      template<typename T, typename... Ts>
    64      struct all_but_last<std::tuple<T, Ts...> >
    65      {
    66          using C    = std::tuple<T, Ts...>;
    67          using S    = typename MkSeq<std::tuple_size<C>::value - 1>::type;
    68          using type = typename permute_tuple<C, S>::type;
    69      };
    70  
    71      template<typename T, typename... Ts>
    72      struct all_but_last: public all_but_last<std::tuple<T, Ts...> > {};
    73  
    74      template<typename... Ts>
    75      using all_but_last_t = typename all_but_last<Ts...>::type;
    76  
    77      // NB.: This is here because there's no constexpr std::max in C++11
    78      template<std::size_t S0, std::size_t... SS> struct max_of_t
    79      {
    80          static constexpr const std::size_t rest  = max_of_t<SS...>::value;
    81          static constexpr const std::size_t value = rest > S0 ? rest : S0;
    82      };
    83      template<std::size_t S> struct max_of_t<S>
    84      {
    85          static constexpr const std::size_t value = S;
    86      };
    87  
    88      template <typename...>
    89      struct contains : std::false_type{};
    90  
    91      template <typename T1, typename T2, typename... Ts>
    92      struct contains<T1, T2, Ts...> : std::integral_constant<bool, std::is_same<T1, T2>::value ||
    93                                                                    contains<T1, Ts...>::value> {};
    94      template<typename T, typename... Types>
    95      struct contains<T, std::tuple<Types...>> : std::integral_constant<bool, contains<T, Types...>::value> {};
    96  
    97      template <typename...>
    98      struct all_unique : std::true_type{};
    99  
   100      template <typename T1, typename... Ts>
   101      struct all_unique<T1, Ts...> : std::integral_constant<bool, !contains<T1, Ts...>::value &&
   102                                                                   all_unique<Ts...>::value> {};
   103  
   104      template<typename>
   105      struct tuple_wrap_helper;
   106  
   107      template<typename T> struct tuple_wrap_helper
   108      {
   109          using type = std::tuple<T>;
   110          static type get(T&& obj) { return std::make_tuple(std::move(obj)); }
   111      };
   112  
   113      template<typename... Objs>
   114      struct tuple_wrap_helper<std::tuple<Objs...>>
   115      {
   116          using type = std::tuple<Objs...>;
   117          static type get(std::tuple<Objs...>&& objs) { return std::forward<std::tuple<Objs...>>(objs); }
   118      };
   119  } // namespace detail
   120  } // namespace cv
   121  
   122  // \endcond
   123  
   124  #endif //  OPENCV_GAPI_UTIL_HPP