Update boost to 1.71 and add asio

boost/asio/detail/executor_op.hpp

@@ -0,0 +1,86 @@
+//
+// detail/executor_op.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_DETAIL_EXECUTOR_OP_HPP
+#define BOOST_ASIO_DETAIL_EXECUTOR_OP_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/fenced_block.hpp>
+#include <boost/asio/detail/handler_alloc_helpers.hpp>
+#include <boost/asio/detail/handler_invoke_helpers.hpp>
+#include <boost/asio/detail/scheduler_operation.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+template <typename Handler, typename Alloc,
+    typename Operation = scheduler_operation>
+class executor_op : public Operation
+{
+public:
+  BOOST_ASIO_DEFINE_HANDLER_ALLOCATOR_PTR(executor_op);
+
+  template <typename H>
+  executor_op(BOOST_ASIO_MOVE_ARG(H) h, const Alloc& allocator)
+    : Operation(&executor_op::do_complete),
+      handler_(BOOST_ASIO_MOVE_CAST(H)(h)),
+      allocator_(allocator)
+  {
+  }
+
+  static void do_complete(void* owner, Operation* base,
+      const boost::system::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    // Take ownership of the handler object.
+    executor_op* o(static_cast<executor_op*>(base));
+    Alloc allocator(o->allocator_);
+    ptr p = { detail::addressof(allocator), o, o };
+
+    BOOST_ASIO_HANDLER_COMPLETION((*o));
+
+    // Make a copy of the handler so that the memory can be deallocated before
+    // the upcall is made. Even if we're not about to make an upcall, a
+    // sub-object of the handler may be the true owner of the memory associated
+    // with the handler. Consequently, a local copy of the handler is required
+    // to ensure that any owning sub-object remains valid until after we have
+    // deallocated the memory here.
+    Handler handler(BOOST_ASIO_MOVE_CAST(Handler)(o->handler_));
+    p.reset();
+
+    // Make the upcall if required.
+    if (owner)
+    {
+      fenced_block b(fenced_block::half);
+      BOOST_ASIO_HANDLER_INVOCATION_BEGIN(());
+      boost_asio_handler_invoke_helpers::invoke(handler, handler);
+      BOOST_ASIO_HANDLER_INVOCATION_END;
+    }
+  }
+
+private:
+  Handler handler_;
+  Alloc allocator_;
+};
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_EXECUTOR_OP_HPP