Update boost to 1.71 and add asio

boost/asio/bind_executor.hpp

@@ -0,0 +1,582 @@
+//
+// bind_executor.hpp
+// ~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 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)
+//
+
+#ifndef BOOST_ASIO_BIND_EXECUTOR_HPP
+#define BOOST_ASIO_BIND_EXECUTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/type_traits.hpp>
+#include <boost/asio/detail/variadic_templates.hpp>
+#include <boost/asio/associated_executor.hpp>
+#include <boost/asio/associated_allocator.hpp>
+#include <boost/asio/async_result.hpp>
+#include <boost/asio/execution_context.hpp>
+#include <boost/asio/is_executor.hpp>
+#include <boost/asio/uses_executor.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename T>
+struct executor_binder_check
+{
+  typedef void type;
+};
+
+// Helper to automatically define nested typedef result_type.
+
+template <typename T, typename = void>
+struct executor_binder_result_type
+{
+protected:
+  typedef void result_type_or_void;
+};
+
+template <typename T>
+struct executor_binder_result_type<T,
+  typename executor_binder_check<typename T::result_type>::type>
+{
+  typedef typename T::result_type result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct executor_binder_result_type<R(*)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R>
+struct executor_binder_result_type<R(&)()>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct executor_binder_result_type<R(*)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1>
+struct executor_binder_result_type<R(&)(A1)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_result_type<R(*)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_result_type<R(&)(A1, A2)>
+{
+  typedef R result_type;
+protected:
+  typedef result_type result_type_or_void;
+};
+
+// Helper to automatically define nested typedef argument_type.
+
+template <typename T, typename = void>
+struct executor_binder_argument_type {};
+
+template <typename T>
+struct executor_binder_argument_type<T,
+  typename executor_binder_check<typename T::argument_type>::type>
+{
+  typedef typename T::argument_type argument_type;
+};
+
+template <typename R, typename A1>
+struct executor_binder_argument_type<R(*)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+template <typename R, typename A1>
+struct executor_binder_argument_type<R(&)(A1)>
+{
+  typedef A1 argument_type;
+};
+
+// Helper to automatically define nested typedefs first_argument_type and
+// second_argument_type.
+
+template <typename T, typename = void>
+struct executor_binder_argument_types {};
+
+template <typename T>
+struct executor_binder_argument_types<T,
+  typename executor_binder_check<typename T::first_argument_type>::type>
+{
+  typedef typename T::first_argument_type first_argument_type;
+  typedef typename T::second_argument_type second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_argument_type<R(*)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+template <typename R, typename A1, typename A2>
+struct executor_binder_argument_type<R(&)(A1, A2)>
+{
+  typedef A1 first_argument_type;
+  typedef A2 second_argument_type;
+};
+
+// Helper to:
+// - Apply the empty base optimisation to the executor.
+// - Perform uses_executor construction of the target type, if required.
+
+template <typename T, typename Executor, bool UsesExecutor>
+class executor_binder_base;
+
+template <typename T, typename Executor>
+class executor_binder_base<T, Executor, true>
+  : protected Executor
+{
+protected:
+  template <typename E, typename U>
+  executor_binder_base(BOOST_ASIO_MOVE_ARG(E) e, BOOST_ASIO_MOVE_ARG(U) u)
+    : executor_(BOOST_ASIO_MOVE_CAST(E)(e)),
+      target_(executor_arg_t(), executor_, BOOST_ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  Executor executor_;
+  T target_;
+};
+
+template <typename T, typename Executor>
+class executor_binder_base<T, Executor, false>
+{
+protected:
+  template <typename E, typename U>
+  executor_binder_base(BOOST_ASIO_MOVE_ARG(E) e, BOOST_ASIO_MOVE_ARG(U) u)
+    : executor_(BOOST_ASIO_MOVE_CAST(E)(e)),
+      target_(BOOST_ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  Executor executor_;
+  T target_;
+};
+
+// Helper to enable SFINAE on zero-argument operator() below.
+
+template <typename T, typename = void>
+struct executor_binder_result_of0
+{
+  typedef void type;
+};
+
+template <typename T>
+struct executor_binder_result_of0<T,
+  typename executor_binder_check<typename result_of<T()>::type>::type>
+{
+  typedef typename result_of<T()>::type type;
+};
+
+} // namespace detail
+
+/// A call wrapper type to bind an executor of type @c Executor to an object of
+/// type @c T.
+template <typename T, typename Executor>
+class executor_binder
+#if !defined(GENERATING_DOCUMENTATION)
+  : public detail::executor_binder_result_type<T>,
+    public detail::executor_binder_argument_type<T>,
+    public detail::executor_binder_argument_types<T>,
+    private detail::executor_binder_base<
+      T, Executor, uses_executor<T, Executor>::value>
+#endif // !defined(GENERATING_DOCUMENTATION)
+{
+public:
+  /// The type of the target object.
+  typedef T target_type;
+
+  /// The type of the associated executor.
+  typedef Executor executor_type;
+
+#if defined(GENERATING_DOCUMENTATION)
+  /// The return type if a function.
+  /**
+   * The type of @c result_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to function type, @c result_type is a synonym for
+   * the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c result_type, then @c
+   * result_type is a synonym for @c T::result_type;
+   *
+   * @li otherwise @c result_type is not defined.
+   */
+  typedef see_below result_type;
+
+  /// The type of the function's argument.
+  /**
+   * The type of @c argument_type is based on the type @c T of the wrapper's
+   * target object:
+   *
+   * @li if @c T is a pointer to a function type accepting a single argument,
+   * @c argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c argument_type, then @c
+   * argument_type is a synonym for @c T::argument_type;
+   *
+   * @li otherwise @c argument_type is not defined.
+   */
+  typedef see_below argument_type;
+
+  /// The type of the function's first argument.
+  /**
+   * The type of @c first_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * first_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c first_argument_type is a synonym for @c T::first_argument_type;
+   *
+   * @li otherwise @c first_argument_type is not defined.
+   */
+  typedef see_below first_argument_type;
+
+  /// The type of the function's second argument.
+  /**
+   * The type of @c second_argument_type is based on the type @c T of the
+   * wrapper's target object:
+   *
+   * @li if @c T is a pointer to a function type accepting two arguments, @c
+   * second_argument_type is a synonym for the return type of @c T;
+   *
+   * @li if @c T is a class type with a member type @c first_argument_type,
+   * then @c second_argument_type is a synonym for @c T::second_argument_type;
+   *
+   * @li otherwise @c second_argument_type is not defined.
+   */
+  typedef see_below second_argument_type;
+#endif // defined(GENERATING_DOCUMENTATION)
+
+  /// Construct an executor wrapper for the specified object.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U>
+  executor_binder(executor_arg_t, const executor_type& e,
+      BOOST_ASIO_MOVE_ARG(U) u)
+    : base_type(e, BOOST_ASIO_MOVE_CAST(U)(u))
+  {
+  }
+
+  /// Copy constructor.
+  executor_binder(const executor_binder& other)
+    : base_type(other.get_executor(), other.get())
+  {
+  }
+
+  /// Construct a copy, but specify a different executor.
+  executor_binder(executor_arg_t, const executor_type& e,
+      const executor_binder& other)
+    : base_type(e, other.get())
+  {
+  }
+
+  /// Construct a copy of a different executor wrapper type.
+  /**
+   * This constructor is only valid if the @c Executor type is constructible
+   * from type @c OtherExecutor, and the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U, typename OtherExecutor>
+  executor_binder(const executor_binder<U, OtherExecutor>& other)
+    : base_type(other.get_executor(), other.get())
+  {
+  }
+
+  /// Construct a copy of a different executor wrapper type, but specify a
+  /// different executor.
+  /**
+   * This constructor is only valid if the type @c T is constructible from type
+   * @c U.
+   */
+  template <typename U, typename OtherExecutor>
+  executor_binder(executor_arg_t, const executor_type& e,
+      const executor_binder<U, OtherExecutor>& other)
+    : base_type(e, other.get())
+  {
+  }
+
+#if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Move constructor.
+  executor_binder(executor_binder&& other)
+    : base_type(BOOST_ASIO_MOVE_CAST(executor_type)(other.get_executor()),
+        BOOST_ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct the target object, but specify a different executor.
+  executor_binder(executor_arg_t, const executor_type& e,
+      executor_binder&& other)
+    : base_type(e, BOOST_ASIO_MOVE_CAST(T)(other.get()))
+  {
+  }
+
+  /// Move construct from a different executor wrapper type.
+  template <typename U, typename OtherExecutor>
+  executor_binder(executor_binder<U, OtherExecutor>&& other)
+    : base_type(BOOST_ASIO_MOVE_CAST(OtherExecutor)(other.get_executor()),
+        BOOST_ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+  /// Move construct from a different executor wrapper type, but specify a
+  /// different executor.
+  template <typename U, typename OtherExecutor>
+  executor_binder(executor_arg_t, const executor_type& e,
+      executor_binder<U, OtherExecutor>&& other)
+    : base_type(e, BOOST_ASIO_MOVE_CAST(U)(other.get()))
+  {
+  }
+
+#endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
+
+  /// Destructor.
+  ~executor_binder()
+  {
+  }
+
+  /// Obtain a reference to the target object.
+  target_type& get() BOOST_ASIO_NOEXCEPT
+  {
+    return this->target_;
+  }
+
+  /// Obtain a reference to the target object.
+  const target_type& get() const BOOST_ASIO_NOEXCEPT
+  {
+    return this->target_;
+  }
+
+  /// Obtain the associated executor.
+  executor_type get_executor() const BOOST_ASIO_NOEXCEPT
+  {
+    return this->executor_;
+  }
+
+#if defined(GENERATING_DOCUMENTATION)
+
+  template <typename... Args> auto operator()(Args&& ...);
+  template <typename... Args> auto operator()(Args&& ...) const;
+
+#elif defined(BOOST_ASIO_HAS_VARIADIC_TEMPLATES)
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      BOOST_ASIO_MOVE_ARG(Args)... args)
+  {
+    return this->target_(BOOST_ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+  /// Forwarding function call operator.
+  template <typename... Args>
+  typename result_of<T(Args...)>::type operator()(
+      BOOST_ASIO_MOVE_ARG(Args)... args) const
+  {
+    return this->target_(BOOST_ASIO_MOVE_CAST(Args)(args)...);
+  }
+
+#elif defined(BOOST_ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typename detail::executor_binder_result_of0<T>::type operator()()
+  {
+    return this->target_();
+  }
+
+  typename detail::executor_binder_result_of0<T>::type operator()() const
+  {
+    return this->target_();
+  }
+
+#define BOOST_ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF(n) \
+  template <BOOST_ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(BOOST_ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      BOOST_ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return this->target_(BOOST_ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <BOOST_ASIO_VARIADIC_TPARAMS(n)> \
+  typename result_of<T(BOOST_ASIO_VARIADIC_TARGS(n))>::type operator()( \
+      BOOST_ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return this->target_(BOOST_ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  BOOST_ASIO_VARIADIC_GENERATE(BOOST_ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF)
+#undef BOOST_ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF
+
+#else // defined(BOOST_ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+  typedef typename detail::executor_binder_result_type<T>::result_type_or_void
+    result_type_or_void;
+
+  result_type_or_void operator()()
+  {
+    return this->target_();
+  }
+
+  result_type_or_void operator()() const
+  {
+    return this->target_();
+  }
+
+#define BOOST_ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF(n) \
+  template <BOOST_ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      BOOST_ASIO_VARIADIC_MOVE_PARAMS(n)) \
+  { \
+    return this->target_(BOOST_ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  \
+  template <BOOST_ASIO_VARIADIC_TPARAMS(n)> \
+  result_type_or_void operator()( \
+      BOOST_ASIO_VARIADIC_MOVE_PARAMS(n)) const \
+  { \
+    return this->target_(BOOST_ASIO_VARIADIC_MOVE_ARGS(n)); \
+  } \
+  /**/
+  BOOST_ASIO_VARIADIC_GENERATE(BOOST_ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF)
+#undef BOOST_ASIO_PRIVATE_BIND_EXECUTOR_CALL_DEF
+
+#endif // defined(BOOST_ASIO_HAS_STD_TYPE_TRAITS) && !defined(_MSC_VER)
+
+private:
+  typedef detail::executor_binder_base<T, Executor,
+    uses_executor<T, Executor>::value> base_type;
+};
+
+/// Associate an object of type @c T with an executor of type @c Executor.
+template <typename Executor, typename T>
+inline executor_binder<typename decay<T>::type, Executor>
+bind_executor(const Executor& ex, BOOST_ASIO_MOVE_ARG(T) t,
+    typename enable_if<is_executor<Executor>::value>::type* = 0)
+{
+  return executor_binder<typename decay<T>::type, Executor>(
+      executor_arg_t(), ex, BOOST_ASIO_MOVE_CAST(T)(t));
+}
+
+/// Associate an object of type @c T with an execution context's executor.
+template <typename ExecutionContext, typename T>
+inline executor_binder<typename decay<T>::type,
+  typename ExecutionContext::executor_type>
+bind_executor(ExecutionContext& ctx, BOOST_ASIO_MOVE_ARG(T) t,
+    typename enable_if<is_convertible<
+      ExecutionContext&, execution_context&>::value>::type* = 0)
+{
+  return executor_binder<typename decay<T>::type,
+    typename ExecutionContext::executor_type>(
+      executor_arg_t(), ctx.get_executor(), BOOST_ASIO_MOVE_CAST(T)(t));
+}
+
+#if !defined(GENERATING_DOCUMENTATION)
+
+template <typename T, typename Executor>
+struct uses_executor<executor_binder<T, Executor>, Executor>
+  : true_type {};
+
+template <typename T, typename Executor, typename Signature>
+class async_result<executor_binder<T, Executor>, Signature>
+{
+public:
+  typedef executor_binder<
+    typename async_result<T, Signature>::completion_handler_type, Executor>
+      completion_handler_type;
+
+  typedef typename async_result<T, Signature>::return_type return_type;
+
+  explicit async_result(executor_binder<T, Executor>& b)
+    : target_(b.get())
+  {
+  }
+
+  return_type get()
+  {
+    return target_.get();
+  }
+
+private:
+  async_result(const async_result&) BOOST_ASIO_DELETED;
+  async_result& operator=(const async_result&) BOOST_ASIO_DELETED;
+
+  async_result<T, Signature> target_;
+};
+
+template <typename T, typename Executor, typename Allocator>
+struct associated_allocator<executor_binder<T, Executor>, Allocator>
+{
+  typedef typename associated_allocator<T, Allocator>::type type;
+
+  static type get(const executor_binder<T, Executor>& b,
+      const Allocator& a = Allocator()) BOOST_ASIO_NOEXCEPT
+  {
+    return associated_allocator<T, Allocator>::get(b.get(), a);
+  }
+};
+
+template <typename T, typename Executor, typename Executor1>
+struct associated_executor<executor_binder<T, Executor>, Executor1>
+{
+  typedef Executor type;
+
+  static type get(const executor_binder<T, Executor>& b,
+      const Executor1& = Executor1()) BOOST_ASIO_NOEXCEPT
+  {
+    return b.get_executor();
+  }
+};
+
+#endif // !defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_BIND_EXECUTOR_HPP