Add make_strand

CHANGELOG.md

@@ -3,6 +3,7 @@ Version 216:
 * Refactor websocket::stream operations
 * Add websocket::stream timeouts
 * Use suggested timeouts in Websocket examples
+* Add make_strand
 
 --------------------------------------------------------------------------------
 

doc/qbk/quickref.xml

@@ -65,12 +65,12 @@
           <member><link linkend="beast.ref.boost__beast__beast_close_socket">beast_close_socket</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__bind_front_handler">bind_front_handler</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__bind_handler">bind_handler</link></member>
-          <member><link linkend="beast.ref.boost__beast__buffer_size">buffer_size</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__close_socket">close_socket</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__connect">connect</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__generic_category">generic_category</link></member>
           <member><link linkend="beast.ref.boost__beast__get_lowest_layer">get_lowest_layer</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__iequals">iequals</link></member>
+          <member><link linkend="beast.ref.boost__beast__make_strand">make_strand</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
           <member><link linkend="beast.ref.boost__beast__to_static_string">to_static_string</link></member>
         </simplelist>
       </entry>
@@ -123,6 +123,7 @@
         <simplelist type="vert" columns="1">
             <member><link linkend="beast.ref.boost__beast__basic_flat_buffer">basic_flat_buffer</link></member>
             <member><link linkend="beast.ref.boost__beast__basic_multi_buffer">basic_multi_buffer</link></member>
+            <member><link linkend="beast.ref.boost__beast__buffer_size">buffer_size</link>&nbsp;<emphasis role="green">&#128946;</emphasis></member>
             <member><link linkend="beast.ref.boost__beast__buffered_read_stream">buffered_read_stream</link></member>
             <member><link linkend="beast.ref.boost__beast__buffers_adaptor">buffers_adaptor</link></member>
             <member><link linkend="beast.ref.boost__beast__buffers_cat_view">buffers_cat_view</link></member>

include/boost/beast/core.hpp

@@ -35,6 +35,7 @@
 #include <boost/beast/core/flat_stream.hpp>
 #include <boost/beast/core/handler_ptr.hpp>
 #include <boost/beast/core/make_printable.hpp>
+#include <boost/beast/core/make_strand.hpp>
 #include <boost/beast/core/multi_buffer.hpp>
 #include <boost/beast/core/ostream.hpp>
 #include <boost/beast/core/read_size.hpp>

include/boost/beast/core/make_strand.hpp

@@ -0,0 +1,60 @@
+//
+// Copyright (c) 2019 Vinnie Falco (vinnie dot falco at gmail 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)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_MAKE_STRAND_HPP
+#define BOOST_BEAST_MAKE_STRAND_HPP
+
+#include <boost/beast/core/detail/config.hpp>
+#include <boost/beast/core/stream_traits.hpp>
+#include <boost/asio/is_executor.hpp>
+#include <boost/asio/strand.hpp>
+#include <type_traits>
+
+namespace boost {
+namespace beast {
+
+/** Return a strand usable with the specified execution context.
+*/
+#if BOOST_BEAST_DOXYGEN
+template<class ExecutionContext>
+__see_below__
+#else
+template<class ExecutionContext
+    ,class = typename std::enable_if<
+        has_get_executor<ExecutionContext>::value &&
+        std::is_convertible<
+            ExecutionContext&,
+            net::execution_context&>::value>::type
+>
+net::strand<executor_type<ExecutionContext>>
+#endif
+make_strand(ExecutionContext& context)
+{
+    return net::strand<executor_type<
+        ExecutionContext>>{context.get_executor()};
+}
+
+/** Return a strand usable with the specified executor.
+*/
+template<class Executor
+#if ! BOOST_BEAST_DOXYGEN
+    , class = typename
+        net::is_executor<Executor>::type
+#endif
+>
+net::strand<Executor>
+make_strand(Executor const& ex)
+{
+    return net::strand<Executor>{ex};
+}
+
+} // beast
+} // boost
+
+#endif

test/beast/core/CMakeLists.txt

@@ -55,6 +55,7 @@ add_executable (tests-beast-core
     flat_stream.cpp
     handler_ptr.cpp
     make_printable.cpp
+    make_strand.cpp
     multi_buffer.cpp
     ostream.cpp
     read_size.cpp

test/beast/core/Jamfile

@@ -43,6 +43,7 @@ local SOURCES =
     flat_stream.cpp
     handler_ptr.cpp
     make_printable.cpp
+    make_strand.cpp
     multi_buffer.cpp
     ostream.cpp
     read_size.cpp

test/beast/core/make_strand.cpp

@@ -0,0 +1,49 @@
+//
+// Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail 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)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+// Test that header file is self-contained.
+#include <boost/beast/core/make_strand.hpp>
+
+#include <boost/beast/_experimental/unit_test/suite.hpp>
+#include <boost/asio/executor.hpp>
+#include <boost/asio/io_context.hpp>
+
+namespace boost {
+namespace beast {
+
+class make_strand_test : public beast::unit_test::suite
+{
+public:
+    void
+    testFunction()
+    {
+        net::io_context ioc;
+        make_strand(ioc);
+        make_strand(ioc.get_executor());
+        make_strand(make_strand(ioc));
+
+        net::executor ex(ioc.get_executor());
+        make_strand(ex);
+
+        // this *should-not* compile
+        //make_strand(ex.context());
+    }
+
+    void
+    run() override
+    {
+        testFunction();
+        pass();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(beast,core,make_strand);
+
+} // beast
+} // boost