SeqAn3  3.2.0
The Modern C++ library for sequence analysis.
out_file_iterator.hpp
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1 // -----------------------------------------------------------------------------------------------------
2 // Copyright (c) 2006-2022, Knut Reinert & Freie Universität Berlin
3 // Copyright (c) 2016-2022, Knut Reinert & MPI für molekulare Genetik
4 // This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
5 // shipped with this file and also available at: https://github.com/seqan/seqan3/blob/master/LICENSE.md
6 // -----------------------------------------------------------------------------------------------------
7 
13 #pragma once
14 
15 #include <cassert>
16 #include <ranges>
17 
18 #include <seqan3/core/platform.hpp>
19 
20 namespace seqan3::detail
21 {
22 
45 template <typename file_type>
46 class out_file_iterator
47 {
48  static_assert(!std::is_const_v<file_type>,
49  "You cannot iterate over const files, because the iterator changes the file.");
50 
51 public:
58  using value_type = void;
60  using reference = void;
62  using const_reference = void;
64  using size_type = void;
66  using difference_type = std::ptrdiff_t;
68  using pointer = void *;
70  using iterator_category = std::output_iterator_tag;
72 
77  constexpr out_file_iterator() = default;
79  constexpr out_file_iterator(out_file_iterator const &) = default;
81  constexpr out_file_iterator & operator=(out_file_iterator const &) = default;
83  constexpr out_file_iterator(out_file_iterator &&) = default;
85  constexpr out_file_iterator & operator=(out_file_iterator &&) = default;
87  ~out_file_iterator() = default;
88 
90  constexpr out_file_iterator(file_type & _host) noexcept : host{&_host}
91  {}
93 
98  out_file_iterator & operator++()
99  {
100  return *this;
101  }
102 
104  out_file_iterator operator++(int)
105  {
106  return *this;
107  }
108 
110 
111  out_file_iterator & operator*() noexcept
112  {
113  return *this;
114  }
115 
120  template <typename arg_t>
121  out_file_iterator & operator=(arg_t && arg)
122  {
123  assert(host != nullptr);
124  host->push_back(std::forward<arg_t>(arg));
125  return *this;
126  }
128 
135  constexpr bool operator==(std::default_sentinel_t const &) const noexcept
136  {
137  return false;
138  }
139 
141  constexpr bool operator!=(std::default_sentinel_t const &) const noexcept
142  {
143  return true;
144  }
145 
147  constexpr friend bool operator==(std::default_sentinel_t const &, out_file_iterator const & it) noexcept
148  {
149  return (it == std::default_sentinel);
150  }
151 
153  constexpr friend bool operator!=(std::default_sentinel_t const &, out_file_iterator const & it) noexcept
154  {
155  return (it != std::default_sentinel);
156  }
158 
159 private:
161  file_type * host{};
162 };
163 
164 } // namespace seqan3::detail
T operator!=(T... args)
Provides platform and dependency checks.
The <ranges> header from C++20's standard library.