update ceph source to reef 18.1.2

[ceph.git] / ceph / src / boost / boost / asio / associated_executor.hpp

diff --git a/ceph/src/boost/boost/asio/associated_executor.hpp b/ceph/src/boost/boost/asio/associated_executor.hpp
index a44190b5fde9ae55540ebf554969e0e97c02c77c..02738aac820d6270bedb0abc8424b585e1795d3d 100644 (file)
--- a/ceph/src/boost/boost/asio/associated_executor.hpp
+++ b/ceph/src/boost/boost/asio/associated_executor.hpp
@@ -2,7 +2,7 @@
 // associated_executor.hpp
 // ~~~~~~~~~~~~~~~~~~~~~~~
 //
-// Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2003-2022 Christopher M. Kohlhoff (chris at kohlhoff dot com)
 //
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -16,7 +16,10 @@
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
 
 #include <boost/asio/detail/config.hpp>
+#include <boost/asio/associator.hpp>
+#include <boost/asio/detail/functional.hpp>
 #include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/execution/executor.hpp>
 #include <boost/asio/is_executor.hpp>
 #include <boost/asio/system_executor.hpp>
 
@@ -24,20 +27,32 @@
 
 namespace boost {
 namespace asio {
+
+template <typename T, typename Executor>
+struct associated_executor;
+
 namespace detail {
 
-template <typename>
-struct associated_executor_check
+template <typename T, typename = void>
+struct has_executor_type : false_type
 {
-  typedef void type;
 };
 
-template <typename T, typename E, typename = void>
+template <typename T>
+struct has_executor_type<T,
+  typename void_type<typename T::executor_type>::type>
+    : true_type
+{
+};
+
+template <typename T, typename E, typename = void, typename = void>
 struct associated_executor_impl
 {
+  typedef void asio_associated_executor_is_unspecialised;
+
   typedef E type;
 
-  static type get(const T&, const E& e) BOOST_ASIO_NOEXCEPT
+  static type get(const T&, const E& e = E()) BOOST_ASIO_NOEXCEPT
   {
     return e;
   }
@@ -45,16 +60,27 @@ struct associated_executor_impl
 
 template <typename T, typename E>
 struct associated_executor_impl<T, E,
-  typename associated_executor_check<typename T::executor_type>::type>
+  typename void_type<typename T::executor_type>::type>
 {
   typedef typename T::executor_type type;
 
-  static type get(const T& t, const E&) BOOST_ASIO_NOEXCEPT
+  static type get(const T& t, const E& = E()) BOOST_ASIO_NOEXCEPT
   {
     return t.get_executor();
   }
 };
 
+template <typename T, typename E>
+struct associated_executor_impl<T, E,
+  typename enable_if<
+    !has_executor_type<T>::value
+  >::type,
+  typename void_type<
+    typename associator<associated_executor, T, E>::type
+  >::type> : associator<associated_executor, T, E>
+{
+};
+
 } // namespace detail
 
 /// Traits type used to obtain the executor associated with an object.
@@ -78,22 +104,20 @@ struct associated_executor_impl<T, E,
  */
 template <typename T, typename Executor = system_executor>
 struct associated_executor
+#if !defined(GENERATING_DOCUMENTATION)
+  : detail::associated_executor_impl<T, Executor>
+#endif // !defined(GENERATING_DOCUMENTATION)
 {
+#if defined(GENERATING_DOCUMENTATION)
   /// If @c T has a nested type @c executor_type, <tt>T::executor_type</tt>.
   /// Otherwise @c Executor.
-#if defined(GENERATING_DOCUMENTATION)
   typedef see_below type;
-#else // defined(GENERATING_DOCUMENTATION)
-  typedef typename detail::associated_executor_impl<T, Executor>::type type;
-#endif // defined(GENERATING_DOCUMENTATION)
 
   /// If @c T has a nested type @c executor_type, returns
   /// <tt>t.get_executor()</tt>. Otherwise returns @c ex.
   static type get(const T& t,
-      const Executor& ex = Executor()) BOOST_ASIO_NOEXCEPT
-  {
-    return detail::associated_executor_impl<T, Executor>::get(t, ex);
-  }
+      const Executor& ex = Executor()) BOOST_ASIO_NOEXCEPT;
+#endif // defined(GENERATING_DOCUMENTATION)
 };
 
 /// Helper function to obtain an object's associated executor.
@@ -101,7 +125,7 @@ struct associated_executor
  * @returns <tt>associated_executor<T>::get(t)</tt>
  */
 template <typename T>
-inline typename associated_executor<T>::type
+BOOST_ASIO_NODISCARD inline typename associated_executor<T>::type
 get_associated_executor(const T& t) BOOST_ASIO_NOEXCEPT
 {
   return associated_executor<T>::get(t);
@@ -112,10 +136,11 @@ get_associated_executor(const T& t) BOOST_ASIO_NOEXCEPT
  * @returns <tt>associated_executor<T, Executor>::get(t, ex)</tt>
  */
 template <typename T, typename Executor>
-inline typename associated_executor<T, Executor>::type
+BOOST_ASIO_NODISCARD inline typename associated_executor<T, Executor>::type
 get_associated_executor(const T& t, const Executor& ex,
-    typename enable_if<is_executor<
-      Executor>::value>::type* = 0) BOOST_ASIO_NOEXCEPT
+    typename constraint<
+      is_executor<Executor>::value || execution::is_executor<Executor>::value
+    >::type = 0) BOOST_ASIO_NOEXCEPT
 {
   return associated_executor<T, Executor>::get(t, ex);
 }
@@ -126,11 +151,11 @@ get_associated_executor(const T& t, const Executor& ex,
  * ExecutionContext::executor_type>::get(t, ctx.get_executor())</tt>
  */
 template <typename T, typename ExecutionContext>
-inline typename associated_executor<T,
+BOOST_ASIO_NODISCARD inline typename associated_executor<T,
   typename ExecutionContext::executor_type>::type
 get_associated_executor(const T& t, ExecutionContext& ctx,
-    typename enable_if<is_convertible<ExecutionContext&,
-      execution_context&>::value>::type* = 0) BOOST_ASIO_NOEXCEPT
+    typename constraint<is_convertible<ExecutionContext&,
+      execution_context&>::value>::type = 0) BOOST_ASIO_NOEXCEPT
 {
   return associated_executor<T,
     typename ExecutionContext::executor_type>::get(t, ctx.get_executor());
@@ -143,6 +168,54 @@ using associated_executor_t = typename associated_executor<T, Executor>::type;
 
 #endif // defined(BOOST_ASIO_HAS_ALIAS_TEMPLATES)
 
+namespace detail {
+
+template <typename T, typename E, typename = void>
+struct associated_executor_forwarding_base
+{
+};
+
+template <typename T, typename E>
+struct associated_executor_forwarding_base<T, E,
+    typename enable_if<
+      is_same<
+        typename associated_executor<T,
+          E>::asio_associated_executor_is_unspecialised,
+        void
+      >::value
+    >::type>
+{
+  typedef void asio_associated_executor_is_unspecialised;
+};
+
+} // namespace detail
+
+#if defined(BOOST_ASIO_HAS_STD_REFERENCE_WRAPPER) \
+  || defined(GENERATING_DOCUMENTATION)
+
+/// Specialisation of associated_executor for @c std::reference_wrapper.
+template <typename T, typename Executor>
+struct associated_executor<reference_wrapper<T>, Executor>
+#if !defined(GENERATING_DOCUMENTATION)
+  : detail::associated_executor_forwarding_base<T, Executor>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+  /// Forwards @c type to the associator specialisation for the unwrapped type
+  /// @c T.
+  typedef typename associated_executor<T, Executor>::type type;
+
+  /// Forwards the request to get the executor to the associator specialisation
+  /// for the unwrapped type @c T.
+  static type get(reference_wrapper<T> t,
+      const Executor& ex = Executor()) BOOST_ASIO_NOEXCEPT
+  {
+    return associated_executor<T, Executor>::get(t.get(), ex);
+  }
+};
+
+#endif // defined(BOOST_ASIO_HAS_STD_REFERENCE_WRAPPER)
+       //   || defined(GENERATING_DOCUMENTATION)
+
 } // namespace asio
 } // namespace boost