text: //
  // post.hpp
  // ~~~~~~~~
  //
  // Copyright (c) 2003-2020 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 ASIO_POST_HPP
  #define ASIO_POST_HPP
  
  #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  # pragma once
  #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  
  #include "asio/detail/config.hpp"
  #include "asio/async_result.hpp"
  #include "asio/detail/type_traits.hpp"
  #include "asio/execution_context.hpp"
  #include "asio/is_executor.hpp"
  
  #include "asio/detail/push_options.hpp"
  
  namespace asio {
  
  /// Submits a completion token or function object for execution.
  /**
   * This function submits an object for execution using the object's associated
   * executor. The function object is queued for execution, and is never called
   * from the current thread prior to returning from <tt>post()</tt>.
   *
   * The use of @c post(), rather than @ref defer(), indicates the caller's
   * preference that the function object be eagerly queued for execution.
   *
   * This function has the following effects:
   *
   * @li Constructs a function object handler of type @c Handler, initialized
   * with <tt>handler(forward<CompletionToken>(token))</tt>.
   *
   * @li Constructs an object @c result of type <tt>async_result<Handler></tt>,
   * initializing the object as <tt>result(handler)</tt>.
   *
   * @li Obtains the handler's associated executor object @c ex by performing
   * <tt>get_associated_executor(handler)</tt>.
   *
   * @li Obtains the handler's associated allocator object @c alloc by performing
   * <tt>get_associated_allocator(handler)</tt>.
   *
   * @li Performs <tt>ex.post(std::move(handler), alloc)</tt>.
   *
   * @li Returns <tt>result.get()</tt>.
   */
  template <ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken>
  ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
      ASIO_MOVE_ARG(CompletionToken) token);
  
  /// Submits a completion token or function object for execution.
  /**
   * This function submits an object for execution using the specified executor.
   * The function object is queued for execution, and is never called from the
   * current thread prior to returning from <tt>post()</tt>.
   *
   * The use of @c post(), rather than @ref defer(), indicates the caller's
   * preference that the function object be eagerly queued for execution.
   *
   * This function has the following effects:
   *
   * @li Constructs a function object handler of type @c Handler, initialized
   * with <tt>handler(forward<CompletionToken>(token))</tt>.
   *
   * @li Constructs an object @c result of type <tt>async_result<Handler></tt>,
   * initializing the object as <tt>result(handler)</tt>.
   *
   * @li Obtains the handler's associated executor object @c ex1 by performing
   * <tt>get_associated_executor(handler)</tt>.
   *
   * @li Creates a work object @c w by performing <tt>make_work(ex1)</tt>.
   *
   * @li Obtains the handler's associated allocator object @c alloc by performing
   * <tt>get_associated_allocator(handler)</tt>.
   *
   * @li Constructs a function object @c f with a function call operator that
   * performs <tt>ex1.dispatch(std::move(handler), alloc)</tt> followed by
   * <tt>w.reset()</tt>.
   *
   * @li Performs <tt>Executor(ex).post(std::move(f), alloc)</tt>.
   *
   * @li Returns <tt>result.get()</tt>.
   */
  template <typename Executor,
      ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken
        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(Executor)>
  ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
      const Executor& ex,
      ASIO_MOVE_ARG(CompletionToken) token
        ASIO_DEFAULT_COMPLETION_TOKEN(Executor),
      typename enable_if<is_executor<Executor>::value>::type* = 0);
  
  /// Submits a completion token or function object for execution.
  /**
   * @returns <tt>post(ctx.get_executor(), forward<CompletionToken>(token))</tt>.
   */
  template <typename ExecutionContext,
      ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken
        ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
          typename ExecutionContext::executor_type)>
  ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
      ExecutionContext& ctx,
      ASIO_MOVE_ARG(CompletionToken) token
        ASIO_DEFAULT_COMPLETION_TOKEN(
          typename ExecutionContext::executor_type),
      typename enable_if<is_convertible<
        ExecutionContext&, execution_context&>::value>::type* = 0);
  
  } // namespace asio
  
  #include "asio/detail/pop_options.hpp"
  
  #include "asio/impl/post.hpp"
  
  #endif // ASIO_POST_HPP
  