Fix move-only arguments in bind_handler

CHANGELOG.md

@@ -1,6 +1,7 @@
 Version 172:
 
 * Tidy up websocket stream javadocs
+* Fix move-only arguments in bind_handler
 
 --------------------------------------------------------------------------------
 

include/boost/beast/core/detail/bind_handler.hpp

@@ -51,10 +51,10 @@ class bound_handler
         boost::is_placeholder<typename
             std::decay<Arg>::type>::value == 0,
         Arg&&>::type
-    extract(Arg&& arg, Vals& vals)
+    extract(Arg&& arg, Vals&& vals)
     {
         boost::ignore_unused(vals);
-        return arg;
+        return std::forward<Arg>(arg);
     }
 
     template<class Arg, class Vals>
@@ -101,7 +101,7 @@ class bound_handler
         index_sequence<S...>)
     {
         boost::ignore_unused(args);
-        h(std::get<S>(args)...);
+        h(std::get<S>(std::move(args))...);
     }
 
     template<
@@ -118,7 +118,7 @@ class bound_handler
     {
         boost::ignore_unused(args);
         boost::ignore_unused(vals);
-        h(extract(std::get<S>(args),
+        h(extract(std::get<S>(std::move(args)),
             std::forward<ValsTuple>(vals))...);
     }
 

test/beast/core/bind_handler.cpp

@@ -81,6 +81,21 @@ public:
             s.wrap(copyable_handler{}));
     }
 
+    struct move_only
+    {
+        move_only() = default;
+        move_only(move_only&&) = default;
+        move_only(move_only const&) = delete;
+    };
+
+    void
+    testMoveOnly()
+    {
+        bind_handler([](move_only){}, move_only{})();
+        bind_handler([](move_only){}, std::placeholders::_1)(move_only{});
+        bind_handler([](move_only, move_only){}, move_only{}, std::placeholders::_1)(move_only{});
+    }
+
     void
     run() override
     {
@@ -90,6 +105,7 @@ public:
         f();
         testPlaceholders();
         testAsioHandlerInvoke();
+        testMoveOnly();
     }
 };