is_buffer_sequence.hpp 7.1 KB

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  1. //
  2. // detail/is_buffer_sequence.hpp
  3. // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  4. //
  5. // Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
  6. //
  7. // Distributed under the Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9. //
  10. #ifndef BOOST_ASIO_DETAIL_IS_BUFFER_SEQUENCE_HPP
  11. #define BOOST_ASIO_DETAIL_IS_BUFFER_SEQUENCE_HPP
  12. #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  13. # pragma once
  14. #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  15. #include <boost/asio/detail/config.hpp>
  16. #include <boost/asio/detail/type_traits.hpp>
  17. #include <boost/asio/detail/push_options.hpp>
  18. namespace boost {
  19. namespace asio {
  20. class mutable_buffer;
  21. class const_buffer;
  22. class mutable_registered_buffer;
  23. class const_registered_buffer;
  24. namespace detail {
  25. struct buffer_sequence_memfns_base
  26. {
  27. void begin();
  28. void end();
  29. void size();
  30. void max_size();
  31. void capacity();
  32. void data();
  33. void prepare();
  34. void commit();
  35. void consume();
  36. void grow();
  37. void shrink();
  38. };
  39. template <typename T>
  40. struct buffer_sequence_memfns_derived
  41. : T, buffer_sequence_memfns_base
  42. {
  43. };
  44. template <typename T, T>
  45. struct buffer_sequence_memfns_check
  46. {
  47. };
  48. template <typename>
  49. char buffer_sequence_begin_helper(...);
  50. template <typename T>
  51. char (&buffer_sequence_begin_helper(T* t,
  52. enable_if_t<!is_same<
  53. decltype(boost::asio::buffer_sequence_begin(*t)),
  54. void>::value>*))[2];
  55. template <typename>
  56. char buffer_sequence_end_helper(...);
  57. template <typename T>
  58. char (&buffer_sequence_end_helper(T* t,
  59. enable_if_t<!is_same<
  60. decltype(boost::asio::buffer_sequence_end(*t)),
  61. void>::value>*))[2];
  62. template <typename>
  63. char (&size_memfn_helper(...))[2];
  64. template <typename T>
  65. char size_memfn_helper(
  66. buffer_sequence_memfns_check<
  67. void (buffer_sequence_memfns_base::*)(),
  68. &buffer_sequence_memfns_derived<T>::size>*);
  69. template <typename>
  70. char (&max_size_memfn_helper(...))[2];
  71. template <typename T>
  72. char max_size_memfn_helper(
  73. buffer_sequence_memfns_check<
  74. void (buffer_sequence_memfns_base::*)(),
  75. &buffer_sequence_memfns_derived<T>::max_size>*);
  76. template <typename>
  77. char (&capacity_memfn_helper(...))[2];
  78. template <typename T>
  79. char capacity_memfn_helper(
  80. buffer_sequence_memfns_check<
  81. void (buffer_sequence_memfns_base::*)(),
  82. &buffer_sequence_memfns_derived<T>::capacity>*);
  83. template <typename>
  84. char (&data_memfn_helper(...))[2];
  85. template <typename T>
  86. char data_memfn_helper(
  87. buffer_sequence_memfns_check<
  88. void (buffer_sequence_memfns_base::*)(),
  89. &buffer_sequence_memfns_derived<T>::data>*);
  90. template <typename>
  91. char (&prepare_memfn_helper(...))[2];
  92. template <typename T>
  93. char prepare_memfn_helper(
  94. buffer_sequence_memfns_check<
  95. void (buffer_sequence_memfns_base::*)(),
  96. &buffer_sequence_memfns_derived<T>::prepare>*);
  97. template <typename>
  98. char (&commit_memfn_helper(...))[2];
  99. template <typename T>
  100. char commit_memfn_helper(
  101. buffer_sequence_memfns_check<
  102. void (buffer_sequence_memfns_base::*)(),
  103. &buffer_sequence_memfns_derived<T>::commit>*);
  104. template <typename>
  105. char (&consume_memfn_helper(...))[2];
  106. template <typename T>
  107. char consume_memfn_helper(
  108. buffer_sequence_memfns_check<
  109. void (buffer_sequence_memfns_base::*)(),
  110. &buffer_sequence_memfns_derived<T>::consume>*);
  111. template <typename>
  112. char (&grow_memfn_helper(...))[2];
  113. template <typename T>
  114. char grow_memfn_helper(
  115. buffer_sequence_memfns_check<
  116. void (buffer_sequence_memfns_base::*)(),
  117. &buffer_sequence_memfns_derived<T>::grow>*);
  118. template <typename>
  119. char (&shrink_memfn_helper(...))[2];
  120. template <typename T>
  121. char shrink_memfn_helper(
  122. buffer_sequence_memfns_check<
  123. void (buffer_sequence_memfns_base::*)(),
  124. &buffer_sequence_memfns_derived<T>::shrink>*);
  125. template <typename, typename>
  126. char (&buffer_sequence_element_type_helper(...))[2];
  127. template <typename T, typename Buffer>
  128. char buffer_sequence_element_type_helper(T* t,
  129. enable_if_t<is_convertible<
  130. decltype(*boost::asio::buffer_sequence_begin(*t)),
  131. Buffer>::value>*);
  132. template <typename>
  133. char (&const_buffers_type_typedef_helper(...))[2];
  134. template <typename T>
  135. char const_buffers_type_typedef_helper(
  136. typename T::const_buffers_type*);
  137. template <typename>
  138. char (&mutable_buffers_type_typedef_helper(...))[2];
  139. template <typename T>
  140. char mutable_buffers_type_typedef_helper(
  141. typename T::mutable_buffers_type*);
  142. template <typename T, typename Buffer>
  143. struct is_buffer_sequence_class
  144. : integral_constant<bool,
  145. sizeof(buffer_sequence_begin_helper<T>(0, 0)) != 1 &&
  146. sizeof(buffer_sequence_end_helper<T>(0, 0)) != 1 &&
  147. sizeof(buffer_sequence_element_type_helper<T, Buffer>(0, 0)) == 1>
  148. {
  149. };
  150. template <typename T, typename Buffer>
  151. struct is_buffer_sequence
  152. : conditional<is_class<T>::value,
  153. is_buffer_sequence_class<T, Buffer>,
  154. false_type>::type
  155. {
  156. };
  157. template <>
  158. struct is_buffer_sequence<mutable_buffer, mutable_buffer>
  159. : true_type
  160. {
  161. };
  162. template <>
  163. struct is_buffer_sequence<mutable_buffer, const_buffer>
  164. : true_type
  165. {
  166. };
  167. template <>
  168. struct is_buffer_sequence<const_buffer, const_buffer>
  169. : true_type
  170. {
  171. };
  172. template <>
  173. struct is_buffer_sequence<const_buffer, mutable_buffer>
  174. : false_type
  175. {
  176. };
  177. template <>
  178. struct is_buffer_sequence<mutable_registered_buffer, mutable_buffer>
  179. : true_type
  180. {
  181. };
  182. template <>
  183. struct is_buffer_sequence<mutable_registered_buffer, const_buffer>
  184. : true_type
  185. {
  186. };
  187. template <>
  188. struct is_buffer_sequence<const_registered_buffer, const_buffer>
  189. : true_type
  190. {
  191. };
  192. template <>
  193. struct is_buffer_sequence<const_registered_buffer, mutable_buffer>
  194. : false_type
  195. {
  196. };
  197. template <typename T>
  198. struct is_dynamic_buffer_class_v1
  199. : integral_constant<bool,
  200. sizeof(size_memfn_helper<T>(0)) != 1 &&
  201. sizeof(max_size_memfn_helper<T>(0)) != 1 &&
  202. sizeof(capacity_memfn_helper<T>(0)) != 1 &&
  203. sizeof(data_memfn_helper<T>(0)) != 1 &&
  204. sizeof(consume_memfn_helper<T>(0)) != 1 &&
  205. sizeof(prepare_memfn_helper<T>(0)) != 1 &&
  206. sizeof(commit_memfn_helper<T>(0)) != 1 &&
  207. sizeof(const_buffers_type_typedef_helper<T>(0)) == 1 &&
  208. sizeof(mutable_buffers_type_typedef_helper<T>(0)) == 1>
  209. {
  210. };
  211. template <typename T>
  212. struct is_dynamic_buffer_v1
  213. : conditional<is_class<T>::value,
  214. is_dynamic_buffer_class_v1<T>,
  215. false_type>::type
  216. {
  217. };
  218. template <typename T>
  219. struct is_dynamic_buffer_class_v2
  220. : integral_constant<bool,
  221. sizeof(size_memfn_helper<T>(0)) != 1 &&
  222. sizeof(max_size_memfn_helper<T>(0)) != 1 &&
  223. sizeof(capacity_memfn_helper<T>(0)) != 1 &&
  224. sizeof(data_memfn_helper<T>(0)) != 1 &&
  225. sizeof(consume_memfn_helper<T>(0)) != 1 &&
  226. sizeof(grow_memfn_helper<T>(0)) != 1 &&
  227. sizeof(shrink_memfn_helper<T>(0)) != 1 &&
  228. sizeof(const_buffers_type_typedef_helper<T>(0)) == 1 &&
  229. sizeof(mutable_buffers_type_typedef_helper<T>(0)) == 1>
  230. {
  231. };
  232. template <typename T>
  233. struct is_dynamic_buffer_v2
  234. : conditional<is_class<T>::value,
  235. is_dynamic_buffer_class_v2<T>,
  236. false_type>::type
  237. {
  238. };
  239. } // namespace detail
  240. } // namespace asio
  241. } // namespace boost
  242. #include <boost/asio/detail/pop_options.hpp>
  243. #endif // BOOST_ASIO_DETAIL_IS_BUFFER_SEQUENCE_HPP