text: //
  // impl/post.hpp
  // ~~~~~~~~~~~~~
  //
  // Copyright (c) 2003-2021 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_IMPL_POST_HPP
  #define ASIO_IMPL_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/associated_allocator.hpp"
  #include "asio/associated_executor.hpp"
  #include "asio/detail/work_dispatcher.hpp"
  #include "asio/execution/allocator.hpp"
  #include "asio/execution/blocking.hpp"
  #include "asio/execution/relationship.hpp"
  #include "asio/prefer.hpp"
  #include "asio/require.hpp"
  
  #include "asio/detail/push_options.hpp"
  
  namespace asio {
  namespace detail {
  
  class initiate_post
  {
  public:
    template <typename CompletionHandler>
    void operator()(ASIO_MOVE_ARG(CompletionHandler) handler,
        typename enable_if<
          execution::is_executor<
            typename associated_executor<
              typename decay<CompletionHandler>::type
            >::type
          >::value
        >::type* = 0) const
    {
      typedef typename decay<CompletionHandler>::type handler_t;
  
      typename associated_executor<handler_t>::type ex(
          (get_associated_executor)(handler));
  
      typename associated_allocator<handler_t>::type alloc(
          (get_associated_allocator)(handler));
  
      execution::execute(
          asio::prefer(
            asio::require(ex, execution::blocking.never),
            execution::relationship.fork,
            execution::allocator(alloc)),
          ASIO_MOVE_CAST(CompletionHandler)(handler));
    }
  
    template <typename CompletionHandler>
    void operator()(ASIO_MOVE_ARG(CompletionHandler) handler,
        typename enable_if<
          !execution::is_executor<
            typename associated_executor<
              typename decay<CompletionHandler>::type
            >::type
          >::value
        >::type* = 0) const
    {
      typedef typename decay<CompletionHandler>::type handler_t;
  
      typename associated_executor<handler_t>::type ex(
          (get_associated_executor)(handler));
  
      typename associated_allocator<handler_t>::type alloc(
          (get_associated_allocator)(handler));
  
      ex.post(ASIO_MOVE_CAST(CompletionHandler)(handler), alloc);
    }
  };
  
  template <typename Executor>
  class initiate_post_with_executor
  {
  public:
    typedef Executor executor_type;
  
    explicit initiate_post_with_executor(const Executor& ex)
      : ex_(ex)
    {
    }
  
    executor_type get_executor() const ASIO_NOEXCEPT
    {
      return ex_;
    }
  
    template <typename CompletionHandler>
    void operator()(ASIO_MOVE_ARG(CompletionHandler) handler,
        typename enable_if<
          execution::is_executor<
            typename conditional<true, executor_type, CompletionHandler>::type
          >::value
        >::type* = 0,
        typename enable_if<
          !detail::is_work_dispatcher_required<
            typename decay<CompletionHandler>::type,
            Executor
          >::value
        >::type* = 0) const
    {
      typedef typename decay<CompletionHandler>::type handler_t;
  
      typename associated_allocator<handler_t>::type alloc(
          (get_associated_allocator)(handler));
  
      execution::execute(
          asio::prefer(
            asio::require(ex_, execution::blocking.never),
            execution::relationship.fork,
            execution::allocator(alloc)),
          ASIO_MOVE_CAST(CompletionHandler)(handler));
    }
  
    template <typename CompletionHandler>
    void operator()(ASIO_MOVE_ARG(CompletionHandler) handler,
        typename enable_if<
          execution::is_executor<
            typename conditional<true, executor_type, CompletionHandler>::type
          >::value
        >::type* = 0,
        typename enable_if<
          detail::is_work_dispatcher_required<
            typename decay<CompletionHandler>::type,
            Executor
          >::value
        >::type* = 0) const
    {
      typedef typename decay<CompletionHandler>::type handler_t;
  
      typedef typename associated_executor<
        handler_t, Executor>::type handler_ex_t;
      handler_ex_t handler_ex((get_associated_executor)(handler, ex_));
  
      typename associated_allocator<handler_t>::type alloc(
          (get_associated_allocator)(handler));
  
      execution::execute(
          asio::prefer(
            asio::require(ex_, execution::blocking.never),
            execution::relationship.fork,
            execution::allocator(alloc)),
          detail::work_dispatcher<handler_t, handler_ex_t>(
            ASIO_MOVE_CAST(CompletionHandler)(handler), handler_ex));
    }
  
    template <typename CompletionHandler>
    void operator()(ASIO_MOVE_ARG(CompletionHandler) handler,
        typename enable_if<
          !execution::is_executor<
            typename conditional<true, executor_type, CompletionHandler>::type
          >::value
        >::type* = 0,
        typename enable_if<
          !detail::is_work_dispatcher_required<
            typename decay<CompletionHandler>::type,
            Executor
          >::value
        >::type* = 0) const
    {
      typedef typename decay<CompletionHandler>::type handler_t;
  
      typename associated_allocator<handler_t>::type alloc(
          (get_associated_allocator)(handler));
  
      ex_.post(ASIO_MOVE_CAST(CompletionHandler)(handler), alloc);
    }
  
    template <typename CompletionHandler>
    void operator()(ASIO_MOVE_ARG(CompletionHandler) handler,
        typename enable_if<
          !execution::is_executor<
            typename conditional<true, executor_type, CompletionHandler>::type
          >::value
        >::type* = 0,
        typename enable_if<
          detail::is_work_dispatcher_required<
            typename decay<CompletionHandler>::type,
            Executor
          >::value
        >::type* = 0) const
    {
      typedef typename decay<CompletionHandler>::type handler_t;
  
      typedef typename associated_executor<
        handler_t, Executor>::type handler_ex_t;
      handler_ex_t handler_ex((get_associated_executor)(handler, ex_));
  
      typename associated_allocator<handler_t>::type alloc(
          (get_associated_allocator)(handler));
  
      ex_.post(detail::work_dispatcher<handler_t, handler_ex_t>(
            ASIO_MOVE_CAST(CompletionHandler)(handler),
            handler_ex), alloc);
    }
  
  private:
    Executor ex_;
  };
  
  } // namespace detail
  
  template <ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken>
  ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
      ASIO_MOVE_ARG(CompletionToken) token)
  {
    return async_initiate<CompletionToken, void()>(
        detail::initiate_post(), token);
  }
  
  template <typename Executor,
      ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken>
  ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
      const Executor& ex, ASIO_MOVE_ARG(CompletionToken) token,
      typename enable_if<
        execution::is_executor<Executor>::value || is_executor<Executor>::value
      >::type*)
  {
    return async_initiate<CompletionToken, void()>(
        detail::initiate_post_with_executor<Executor>(ex), token);
  }
  
  template <typename ExecutionContext,
      ASIO_COMPLETION_TOKEN_FOR(void()) CompletionToken>
  inline ASIO_INITFN_AUTO_RESULT_TYPE(CompletionToken, void()) post(
      ExecutionContext& ctx, ASIO_MOVE_ARG(CompletionToken) token,
      typename enable_if<is_convertible<
        ExecutionContext&, execution_context&>::value>::type*)
  {
    return async_initiate<CompletionToken, void()>(
        detail::initiate_post_with_executor<
          typename ExecutionContext::executor_type>(
            ctx.get_executor()), token);
  }
  
  } // namespace asio
  
  #include "asio/detail/pop_options.hpp"
  
  #endif // ASIO_IMPL_POST_HPP
  