Add 1-arity and 2-arity binding to CompletionCall

Subtrees/beast/modules/beast_asio/basics/beast_CompletionCall.h

@@ -30,9 +30,31 @@ class CompletionCall
 public:
     typedef void result_type;
 
-    template <class Handler>
+    // Construction from Handler with zero arguments
+    //
+    template <typename Handler>
     CompletionCall (BOOST_ASIO_MOVE_ARG(Handler) handler)
-        : m_call (new CallType <Handler> (BOOST_ASIO_MOVE_CAST(Handler)(handler)))
+        : m_call (new CallType0 <Handler> (BOOST_ASIO_MOVE_CAST(Handler)(handler)))
+    {
+    }
+
+    // Creates a CompletionHandler with one parameter bound to Handler
+    // This can convert an ErrorCall to a CompletionCall, suitable
+    // for calling asio::io_service::post()
+    //
+    template <typename Handler, typename P1>
+    CompletionCall (BOOST_ASIO_MOVE_ARG(Handler) handler, P1 p1)
+        : m_call (new CallType1 <Handler, P1> (BOOST_ASIO_MOVE_CAST(Handler)(handler), p1))
+    {
+    }
+
+    // Creates a CompletionHandler with two parameters bound to Handler
+    // This can convert a TransferCall to a CompletionCall, suitable
+    // for calling asio::io_service::post()
+    //
+    template <typename Handler, typename P1, typename P2>
+    CompletionCall (BOOST_ASIO_MOVE_ARG(Handler) handler, P1 p1, P2 p2)
+        : m_call (new CallType2 <Handler, P1, P2> (BOOST_ASIO_MOVE_CAST(Handler)(handler), p1, p2))
     {
     }
 
@@ -53,9 +75,9 @@ private:
     };
 
     template <class Handler>
-    struct CallType : Call
+    struct CallType0 : Call
     {
-        CallType (BOOST_ASIO_MOVE_ARG(Handler) handler)
+        CallType0 (BOOST_ASIO_MOVE_ARG(Handler) handler)
             : m_handler (handler)
         {
         }
@@ -68,6 +90,44 @@ private:
         Handler m_handler;
     };
 
+    template <class Handler, typename P1>
+    struct CallType1 : Call
+    {
+        CallType1 (BOOST_ASIO_MOVE_ARG(Handler) handler, P1 p1)
+            : m_handler (handler)
+            , m_p1 (p1)
+        {
+        }
+
+        void operator() ()
+        {
+            m_handler (m_p1);
+        }
+
+        Handler m_handler;
+        P1 m_p1;
+    };
+
+    template <class Handler, typename P1, typename P2>
+    struct CallType2 : Call
+    {
+        CallType2 (BOOST_ASIO_MOVE_ARG(Handler) handler, P1 p1, P2 p2)
+            : m_handler (handler)
+            , m_p1 (p1)
+            , m_p2 (p2)
+        {
+        }
+
+        void operator() ()
+        {
+            m_handler (m_p1, m_p2);
+        }
+
+        Handler m_handler;
+        P1 m_p1;
+        P2 m_p2;
+    };
+
 private:
     SharedObjectPtr <Call> m_call;
 };