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compose.hpp
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1 // Range v3 library
3 //
4 // Copyright Eric Niebler 2013-present
5 //
6 // Use, modification and distribution is subject to the
7 // Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
10 //
11 // Project home: https://github.com/ericniebler/range-v3
12 //
13 #ifndef RANGES_V3_FUNCTIONAL_COMPOSE_HPP
14 #define RANGES_V3_FUNCTIONAL_COMPOSE_HPP
15 
16 #include <type_traits>
17 #include <utility>
18 
19 #include <concepts/concepts.hpp>
20 
21 #include <range/v3/detail/config.hpp>
23 #include <range/v3/utility/static_const.hpp>
24 
25 #include <range/v3/detail/prologue.hpp>
26 
27 namespace ranges
28 {
31  template<typename Second, typename First>
32  struct composed
33  {
34  private:
35  RANGES_NO_UNIQUE_ADDRESS
36  First first_;
37  RANGES_NO_UNIQUE_ADDRESS
38  Second second_;
39 
40  // clang-format off
41  template<typename A, typename B, typename... Ts>
42  static constexpr auto //
43  CPP_auto_fun(do_)(A &&a, B &&b, std::false_type, Ts &&... ts)
44  (
45  return invoke((B &&) b, invoke((A &&) a, (Ts &&) ts...))
46  )
47  template<typename A, typename B, typename... Ts>
48  static constexpr auto CPP_auto_fun(do_)(A &&a, B &&b, std::true_type, Ts &&... ts)
49  (
50  return (invoke((A &&) a, (Ts &&) ts...), invoke((B &&) b))
51  )
52  public:
53  composed() = default;
54  // clang-format on
55  constexpr composed(Second second, First first)
56  : first_(std::move(first))
57  , second_(std::move(second))
58  {}
59  // clang-format off
60  template<typename... Ts>
61  constexpr auto CPP_auto_fun(operator())(Ts &&... ts)(mutable &)
62  (
63  return composed::do_(first_,
64  second_,
65  std::is_void<invoke_result_t<First &, Ts...>>{},
66  (Ts &&) ts...)
67  )
68  template<typename... Ts>
69  constexpr auto CPP_auto_fun(operator())(Ts &&... ts)(const &)
70  (
71  return composed::do_((First const &)first_,
72  (Second const &)second_,
73  std::is_void<invoke_result_t<First const &, Ts...>>{},
74  (Ts &&) ts...)
75  )
76  template<typename... Ts>
77  constexpr auto CPP_auto_fun(operator())(Ts &&... ts)(mutable &&)
78  (
79  return composed::do_((First &&)first_,
80  (Second &&)second_,
81  std::is_void<invoke_result_t<First &&, Ts...>>{},
82  (Ts &&) ts...)
83  )
84  // clang-format on
85  };
86 
87  struct compose_fn
88  {
89  template<typename Second, typename First>
90  constexpr composed<Second, First> operator()(Second second, First first) const
91  {
92  return {std::move(second), std::move(first)};
93  }
94  };
95 
100 } // namespace ranges
101 
102 #include <range/v3/detail/epilogue.hpp>
103 
104 #endif
RANGES_INLINE_VARIABLE(detail::to_container_fn< detail::from_range< std::vector >>, to_vector) template< template< typename... > class ContT > auto to(RANGES_HIDDEN_DETAIL(detail
For initializing a container of the specified type with the elements of an Range.
Definition: conversion.hpp:399
front< Pair > first
Retrieve the first element of the pair Pair.
Definition: meta.hpp:2251
front< pop_front< Pair > > second
Retrieve the first element of the pair Pair.
Definition: meta.hpp:2256
Definition: compose.hpp:88
Definition: compose.hpp:33