Async init-fns use the executor's default token

CHANGELOG.md

@@ -1,3 +1,9 @@
+Version 275:
+
+* Async init-fns use the executor's default token
+
+--------------------------------------------------------------------------------
+
 Version 274:
 
 * Fix leftovers in basic_parser corner case

include/boost/beast/_experimental/http/icy_stream.hpp

@@ -224,11 +224,14 @@ public:
     */
     template<
         class MutableBufferSequence,
-        class ReadHandler>
+        class ReadHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read_some(
         MutableBufferSequence const& buffers,
-        ReadHandler&& handler);
+        ReadHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 
     /** Write some data to the stream.
     
@@ -303,11 +306,14 @@ public:
     */
     template<
         class ConstBufferSequence,
-        class WriteHandler>
+        class WriteHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
     async_write_some(
         ConstBufferSequence const& buffers,
-        WriteHandler&& handler);
+        WriteHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 };
 
 } // http

include/boost/beast/_experimental/test/stream.hpp

@@ -475,9 +475,12 @@ public:
         to ensure that the requested amount of data is read before the asynchronous
         operation completes.
     */
-    template<class MutableBufferSequence, class ReadHandler>
+    template<
+        class MutableBufferSequence,
+        class ReadHandler>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
-    async_read_some(MutableBufferSequence const& buffers,
+    async_read_some(
+        MutableBufferSequence const& buffers,
         ReadHandler&& handler);
 
     /** Write some data to the stream.
@@ -550,9 +553,12 @@ public:
         the peer. Consider using the function `net::async_write` if you need
         to ensure that all data is written before the asynchronous operation completes.
     */
-    template<class ConstBufferSequence, class WriteHandler>
+    template<
+        class ConstBufferSequence,
+        class WriteHandler>
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
-    async_write_some(ConstBufferSequence const& buffers,
+    async_write_some(
+        ConstBufferSequence const& buffers,
         WriteHandler&& handler);
 
 #if ! BOOST_BEAST_DOXYGEN

include/boost/beast/core/basic_stream.hpp

@@ -911,11 +911,16 @@ public:
 
         @see async_connect
     */
-    template<class ConnectHandler>
+    template<
+        class ConnectHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(ConnectHandler)
     async_connect(
         endpoint_type const& ep,
-        ConnectHandler&& handler);
+        ConnectHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Establishes a connection by trying each endpoint in a sequence asynchronously.
 
@@ -960,7 +965,8 @@ public:
     */
     template<
         class EndpointSequence,
-        class RangeConnectHandler
+        class RangeConnectHandler =
+            net::default_completion_token_t<executor_type>
     #if ! BOOST_BEAST_DOXYGEN
         ,class = typename std::enable_if<
             net::is_endpoint_sequence<
@@ -970,7 +976,8 @@ public:
     BOOST_ASIO_INITFN_RESULT_TYPE(RangeConnectHandler,void (error_code, typename Protocol::endpoint))
     async_connect(
         EndpointSequence const& endpoints,
-        RangeConnectHandler&& handler);
+        RangeConnectHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 
     /** Establishes a connection by trying each endpoint in a sequence asynchronously.
 
@@ -1047,7 +1054,8 @@ public:
     template<
         class EndpointSequence,
         class ConnectCondition,
-        class RangeConnectHandler
+        class RangeConnectHandler =
+            net::default_completion_token_t<executor_type>
     #if ! BOOST_BEAST_DOXYGEN
         ,class = typename std::enable_if<
             net::is_endpoint_sequence<
@@ -1058,7 +1066,9 @@ public:
     async_connect(
         EndpointSequence const& endpoints,
         ConnectCondition connect_condition,
-        RangeConnectHandler&& handler);
+        RangeConnectHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Establishes a connection by trying each endpoint in a sequence asynchronously.
 
@@ -1104,11 +1114,13 @@ public:
     */
     template<
         class Iterator,
-        class IteratorConnectHandler>
+        class IteratorConnectHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_ASIO_INITFN_RESULT_TYPE(IteratorConnectHandler,void (error_code, Iterator))
     async_connect(
         Iterator begin, Iterator end,
-        IteratorConnectHandler&& handler);
+        IteratorConnectHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 
     /** Establishes a connection by trying each endpoint in a sequence asynchronously.
 
@@ -1159,12 +1171,14 @@ public:
     template<
         class Iterator,
         class ConnectCondition,
-        class IteratorConnectHandler>
+        class IteratorConnectHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_ASIO_INITFN_RESULT_TYPE(IteratorConnectHandler,void (error_code, Iterator))
     async_connect(
         Iterator begin, Iterator end,
         ConnectCondition connect_condition,
-        IteratorConnectHandler&& handler);
+        IteratorConnectHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 
     //--------------------------------------------------------------------------
 
@@ -1277,11 +1291,17 @@ public:
         to ensure that the requested amount of data is read before the asynchronous
         operation completes.
     */
-    template<class MutableBufferSequence, class ReadHandler>
+    template<
+        class MutableBufferSequence,
+        class ReadHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read_some(
         MutableBufferSequence const& buffers,
-        ReadHandler&& handler);
+        ReadHandler&& handler =
+            net::default_completion_token_t<executor_type>{}
+    );
 
     /** Write some data.
 
@@ -1394,11 +1414,16 @@ public:
         to ensure that the requested amount of data is sent before the asynchronous
         operation completes.
     */
-    template<class ConstBufferSequence, class WriteHandler>
+    template<
+        class ConstBufferSequence,
+        class WriteHandler =
+            net::default_completion_token_t<Executor>
+    >
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
     async_write_some(
         ConstBufferSequence const& buffers,
-        WriteHandler&& handler);
+        WriteHandler&& handler =
+            net::default_completion_token_t<Executor>{});
 };
 
 } // beast

include/boost/beast/core/buffered_read_stream.hpp

@@ -261,10 +261,15 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class MutableBufferSequence, class ReadHandler>
+    template<
+        class MutableBufferSequence,
+        class ReadHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
-    async_read_some(MutableBufferSequence const& buffers,
+    async_read_some(
-        ReadHandler&& handler);
+        MutableBufferSequence const& buffers,
+        ReadHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 
     /** Write some data to the stream.
 
@@ -335,10 +340,15 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class ConstBufferSequence, class WriteHandler>
+    template<
+        class ConstBufferSequence,
+        class WriteHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
-    async_write_some(ConstBufferSequence const& buffers,
+    async_write_some(
-        WriteHandler&& handler);
+        ConstBufferSequence const& buffers,
+        WriteHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 };
 
 } // beast

include/boost/beast/core/detect_ssl.hpp

@@ -316,7 +316,9 @@ detect_ssl(
 template<
     class AsyncReadStream,
     class DynamicBuffer,
-    class CompletionToken>
+    class CompletionToken =
+        net::default_completion_token_t<beast::executor_type<AsyncReadStream>>
+>
 #if BOOST_BEAST_DOXYGEN
 BOOST_ASIO_INITFN_RESULT_TYPE(CompletionToken, void(error_code, bool))
 #else
@@ -325,7 +327,8 @@ auto
 async_detect_ssl(
     AsyncReadStream& stream,
     DynamicBuffer& buffer,
-    CompletionToken&& token) ->
+    CompletionToken&& token = net::default_completion_token_t<
+            beast::executor_type<AsyncReadStream>>{}) ->
         typename net::async_result<
             typename std::decay<CompletionToken>::type, /*< `async_result` customizes the return value based on the completion token >*/
             void(error_code, bool)>::return_type; /*< This is the signature for the completion handler >*/

include/boost/beast/core/flat_stream.hpp

@@ -253,11 +253,13 @@ public:
     */
     template<
         class MutableBufferSequence,
-        class ReadHandler>
+        class ReadHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read_some(
         MutableBufferSequence const& buffers,
-        ReadHandler&& handler);
+        ReadHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 
     /** Write some data to the stream.
     
@@ -332,11 +334,13 @@ public:
     */
     template<
         class ConstBufferSequence,
-        class WriteHandler>
+        class WriteHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
     async_write_some(
         ConstBufferSequence const& buffers,
-        WriteHandler&& handler);
+        WriteHandler&& handler =
+            net::default_completion_token_t<executor_type>{});
 };
 
 } // beast

include/boost/beast/http/read.hpp

@@ -12,6 +12,7 @@
 
 #include <boost/beast/core/detail/config.hpp>
 #include <boost/beast/core/error.hpp>
+#include <boost/beast/core/stream_traits.hpp>
 #include <boost/beast/http/basic_parser.hpp>
 #include <boost/beast/http/message.hpp>
 #include <boost/asio/async_result.hpp>
@@ -204,13 +205,17 @@ template<
     class AsyncReadStream,
     class DynamicBuffer,
     bool isRequest,
-    class ReadHandler>
+    class ReadHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>>
 BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
 async_read_some(
     AsyncReadStream& stream,
     DynamicBuffer& buffer,
     basic_parser<isRequest>& parser,
-    ReadHandler&& handler);
+    ReadHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>{});
 
 //------------------------------------------------------------------------------
 
@@ -397,13 +402,17 @@ template<
     class AsyncReadStream,
     class DynamicBuffer,
     bool isRequest,
-    class ReadHandler>
+    class ReadHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>>
 BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
 async_read_header(
     AsyncReadStream& stream,
     DynamicBuffer& buffer,
     basic_parser<isRequest>& parser,
-    ReadHandler&& handler);
+    ReadHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>{});
 
 //------------------------------------------------------------------------------
 
@@ -590,13 +599,17 @@ template<
     class AsyncReadStream,
     class DynamicBuffer,
     bool isRequest,
-    class ReadHandler>
+    class ReadHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>>
 BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
 async_read(
     AsyncReadStream& stream,
     DynamicBuffer& buffer,
     basic_parser<isRequest>& parser,
-    ReadHandler&& handler);
+    ReadHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>{});
 
 //------------------------------------------------------------------------------
 
@@ -792,13 +805,17 @@ template<
     class AsyncReadStream,
     class DynamicBuffer,
     bool isRequest, class Body, class Allocator,
-    class ReadHandler>
+    class ReadHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>>
 BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
 async_read(
     AsyncReadStream& stream,
     DynamicBuffer& buffer,
     message<isRequest, Body, basic_fields<Allocator>>& msg,
-    ReadHandler&& handler);
+    ReadHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncReadStream>>{});
 
 } // http
 } // beast

include/boost/beast/http/write.hpp

@@ -11,15 +11,12 @@
 #define BOOST_BEAST_HTTP_WRITE_HPP
 
 #include <boost/beast/core/detail/config.hpp>
-#include <boost/beast/core/buffers_cat.hpp>
-#include <boost/beast/core/buffers_suffix.hpp>
-#include <boost/beast/core/multi_buffer.hpp>
 #include <boost/beast/http/message.hpp>
 #include <boost/beast/http/serializer.hpp>
 #include <boost/beast/http/type_traits.hpp>
 #include <boost/beast/http/detail/chunk_encode.hpp>
 #include <boost/beast/core/error.hpp>
-#include <boost/beast/core/string.hpp>
+#include <boost/beast/core/stream_traits.hpp>
 #include <boost/asio/async_result.hpp>
 #include <iosfwd>
 #include <limits>
@@ -169,12 +166,16 @@ write_some(
 template<
     class AsyncWriteStream,
     bool isRequest, class Body, class Fields,
-    class WriteHandler>
+    class WriteHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>>
 BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
 async_write_some(
     AsyncWriteStream& stream,
     serializer<isRequest, Body, Fields>& sr,
-    WriteHandler&& handler);
+    WriteHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>{});
 
 //------------------------------------------------------------------------------
 
@@ -295,12 +296,16 @@ write_header(
 template<
     class AsyncWriteStream,
     bool isRequest, class Body, class Fields,
-    class WriteHandler>
+    class WriteHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>>
 BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
 async_write_header(
     AsyncWriteStream& stream,
     serializer<isRequest, Body, Fields>& sr,
-    WriteHandler&& handler);
+    WriteHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>{});
 
 //------------------------------------------------------------------------------
 
@@ -412,12 +417,16 @@ write(
 template<
     class AsyncWriteStream,
     bool isRequest, class Body, class Fields,
-    class WriteHandler>
+    class WriteHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>>
 BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
 async_write(
     AsyncWriteStream& stream,
     serializer<isRequest, Body, Fields>& sr,
-    WriteHandler&& handler);
+    WriteHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>{});
 
 //------------------------------------------------------------------------------
 
@@ -633,7 +642,9 @@ write(
 template<
     class AsyncWriteStream,
     bool isRequest, class Body, class Fields,
-    class WriteHandler>
+    class WriteHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>>
 #if BOOST_BEAST_DOXYGEN
 BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
 #else
@@ -644,7 +655,9 @@ typename std::enable_if<
 async_write(
     AsyncWriteStream& stream,
     message<isRequest, Body, Fields>& msg,
-    WriteHandler&& handler);
+    WriteHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>);
 
 /** Write a complete message to a stream asynchronously.
 
@@ -692,7 +705,9 @@ async_write(
 template<
     class AsyncWriteStream,
     bool isRequest, class Body, class Fields,
-    class WriteHandler>
+    class WriteHandler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>>
 #if BOOST_BEAST_DOXYGEN
 BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
 #else
@@ -703,7 +718,9 @@ typename std::enable_if<
 async_write(
     AsyncWriteStream& stream,
     message<isRequest, Body, Fields> const& msg,
-    WriteHandler&& handler);
+    WriteHandler&& handler =
+        net::default_completion_token_t<
+            executor_type<AsyncWriteStream>>{});
 
 //------------------------------------------------------------------------------
 

include/boost/beast/websocket/stream.hpp

@@ -875,12 +875,17 @@ public:
         @li <a href="https://tools.ietf.org/html/rfc7230#section-3.1.1">request-target (RFC7230)</a>
         @li <a href="https://tools.ietf.org/html/rfc7230#section-5.3.1">origin-form (RFC7230)</a>
     */
-    template<class HandshakeHandler>
+    template<
+        class HandshakeHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(HandshakeHandler)
     async_handshake(
         string_view host,
         string_view target,
-        HandshakeHandler&& handler);
+        HandshakeHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Perform the WebSocket handshake asynchronously in the client role.
 
@@ -956,13 +961,18 @@ public:
         @li <a href="https://tools.ietf.org/html/rfc7230#section-3.1.1">request-target (RFC7230)</a>
         @li <a href="https://tools.ietf.org/html/rfc7230#section-5.3.1">origin-form (RFC7230)</a>
     */
-    template<class HandshakeHandler>
+    template<
+        class HandshakeHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(HandshakeHandler)
     async_handshake(
         response_type& res,
         string_view host,
         string_view target,
-        HandshakeHandler&& handler);
+        HandshakeHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
     //
@@ -1275,9 +1285,15 @@ public:
         @see
         @li <a href="https://tools.ietf.org/html/rfc6455#section-4.2">Websocket Opening Handshake Server Requirements (RFC6455)</a>
     */
-    template<class AcceptHandler>
+    template<
+        class AcceptHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(AcceptHandler)
-    async_accept(AcceptHandler&& handler);
+    async_accept(
+        AcceptHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Perform the WebSocket handshake asynchronously in the server role.
 
@@ -1338,7 +1354,9 @@ public:
     */
     template<
         class ConstBufferSequence,
-        class AcceptHandler>
+        class AcceptHandler =
+            net::default_completion_token_t<executor_type>
+    >
 #if BOOST_BEAST_DOXYGEN
     void_or_deduced
 #else
@@ -1348,7 +1366,9 @@ public:
 #endif
     async_accept(
         ConstBufferSequence const& buffers,
-        AcceptHandler&& handler);
+        AcceptHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Perform the WebSocket handshake asynchronously in the server role.
 
@@ -1399,12 +1419,16 @@ public:
     */
     template<
         class Body, class Allocator,
-        class AcceptHandler>
+        class AcceptHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(AcceptHandler)
     async_accept(
         http::request<Body,
             http::basic_fields<Allocator>> const& req,
-        AcceptHandler&& handler);
+        AcceptHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
     //
@@ -1529,9 +1553,16 @@ public:
         @see
         @li <a href="https://tools.ietf.org/html/rfc6455#section-7.1.2">Websocket Closing Handshake (RFC6455)</a>
     */
-    template<class CloseHandler>
+    template<
+        class CloseHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(CloseHandler)
-    async_close(close_reason const& cr, CloseHandler&& handler);
+    async_close(
+        close_reason const& cr,
+        CloseHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
     //
@@ -1624,9 +1655,16 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class WriteHandler>
+    template<
+        class WriteHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(WriteHandler)
-    async_ping(ping_data const& payload, WriteHandler&& handler);
+    async_ping(
+        ping_data const& payload,
+        WriteHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Send a websocket pong control frame.
 
@@ -1725,9 +1763,16 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class WriteHandler>
+    template<
+        class WriteHandler =
+            net::default_completion_token_t<executor_type>
+    >
     BOOST_BEAST_ASYNC_RESULT1(WriteHandler)
-    async_pong(ping_data const& payload, WriteHandler&& handler);
+    async_pong(
+        ping_data const& payload,
+        WriteHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
     //
@@ -1879,11 +1924,17 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class DynamicBuffer, class ReadHandler>
+    template<
+        class DynamicBuffer,
+        class ReadHandler =
+            net::default_completion_token_t<
+                executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read(
         DynamicBuffer& buffer,
-        ReadHandler&& handler);
+        ReadHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
 
@@ -2052,12 +2103,18 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class DynamicBuffer, class ReadHandler>
+    template<
+        class DynamicBuffer,
+        class ReadHandler =
+            net::default_completion_token_t<
+                executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read_some(
         DynamicBuffer& buffer,
         std::size_t limit,
-        ReadHandler&& handler);
+        ReadHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
 
@@ -2221,11 +2278,17 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class MutableBufferSequence, class ReadHandler>
+    template<
+        class MutableBufferSequence,
+        class ReadHandler =
+            net::default_completion_token_t<
+                executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read_some(
         MutableBufferSequence const& buffers,
-        ReadHandler&& handler);
+        ReadHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //--------------------------------------------------------------------------
     //
@@ -2340,11 +2403,15 @@ public:
     */
     template<
         class ConstBufferSequence,
-        class WriteHandler>
+        class WriteHandler =
+            net::default_completion_token_t<
+                executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
     async_write(
         ConstBufferSequence const& buffers,
-        WriteHandler&& handler);
+        WriteHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     /** Write some message data.
 
@@ -2457,10 +2524,18 @@ public:
         this function. Invocation of the handler will be performed in a
         manner equivalent to using `net::post`.
     */
-    template<class ConstBufferSequence, class WriteHandler>
+    template<
+        class ConstBufferSequence,
+        class WriteHandler =
+            net::default_completion_token_t<
+                executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
-    async_write_some(bool fin,
+    async_write_some(
-        ConstBufferSequence const& buffers, WriteHandler&& handler);
+        bool fin,
+        ConstBufferSequence const& buffers,
+        WriteHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{});
 
     //
     // Deprecated

test/doc/core_4_layers.cpp

@@ -243,11 +243,15 @@ public:
     }
 
     /// Read some data from the stream asynchronously
-    template <class MutableBufferSequence, class ReadHandler>
+    template<
+        class MutableBufferSequence,
+        class ReadHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(ReadHandler)
     async_read_some(
         MutableBufferSequence const& buffers,
-        ReadHandler&& handler)
+        ReadHandler&& handler =
+            net::default_completion_token_t<executor_type>{})
     {
         return net::async_initiate<
             ReadHandler,
@@ -259,11 +263,16 @@ public:
     }
 
     /// Write some data to the stream asynchronously
-    template <class ConstBufferSequence, class WriteHandler>
+    template<
+        class ConstBufferSequence,
+        class WriteHandler =
+            net::default_completion_token_t<executor_type>>
     BOOST_BEAST_ASYNC_RESULT2(WriteHandler)
     async_write_some(
         ConstBufferSequence const& buffers,
-        WriteHandler&& handler)
+        WriteHandler&& handler =
+            net::default_completion_token_t<
+                executor_type>{})
     {
         return net::async_initiate<
             WriteHandler,