Workaround for msvc-14.0

include/boost/beast/websocket/detail/decorator.hpp

@@ -16,7 +16,6 @@
 #include <boost/core/exchange.hpp>
 #include <boost/type_traits/make_void.hpp>
 #include <algorithm>
-#include <functional>
 #include <memory>
 #include <new>
 #include <type_traits>
@@ -29,19 +28,24 @@ namespace detail {
 
 class decorator
 {
+    friend class decorator_test;
+
     struct incomplete;
 
+    struct exemplar
+    {
+        void(incomplete::*mf)();
+        std::shared_ptr<incomplete> sp;
+        void* param;
+    };
+
     static std::size_t constexpr Bytes =
         beast::detail::max_sizeof<
             void*,
             void const*,
             void(*)(),
             void(incomplete::*)(),
-            decltype(std::bind(
+            exemplar
-                std::declval<
-                    void(incomplete::*)(request_type&)>(),
-                std::shared_ptr<incomplete>{},
-                std::placeholders::_1))
         >();
 
     struct base
@@ -69,28 +73,29 @@ class decorator
 
     struct none
     {
+        void
+        operator()(request_type&)
+        {
+        }
+
+        void
+        operator()(response_type&)
+        {
+        }
     };
 
-    template<class T, class = void>
+    // VFALCO NOTE: When this is two traits, one for
-    struct is_req_op : std::false_type
+    //              request and one for response,
+    //              Visual Studio 2015 fails.
+
+    template<class T, class U, class = void>
+    struct is_op_of : std::false_type
     {
     };
 
-    template<class T>
+    template<class T, class U>
-    struct is_req_op<T, boost::void_t<decltype(
+    struct is_op_of<T, U, boost::void_t<decltype(
-        std::declval<T&>()(std::declval<request_type&>())
+        std::declval<T&>()(std::declval<U&>())
-        )>> : std::true_type
-    {
-    };
-
-    template<class T, class = void>
-    struct is_res_op : std::false_type
-    {
-    };
-
-    template<class T>
-    struct is_res_op<T, boost::void_t<decltype(
-        std::declval<T&>()(std::declval<response_type&>())
         )>> : std::true_type
     {
     };
@@ -120,7 +125,8 @@ class decorator
         void
         invoke(request_type& req) override
         {
-            this->invoke(req, is_req_op<F>{});
+            this->invoke(req,
+                is_op_of<F, request_type>{});
         }
 
         void
@@ -137,7 +143,8 @@ class decorator
         void
         invoke(response_type& res) override
         {
-            this->invoke(res, is_res_op<F>{});
+            this->invoke(res,
+                is_op_of<F, response_type>{});
         }
 
         void

test/beast/websocket/_detail_decorator.cpp

@@ -44,6 +44,9 @@ public:
         }
     };
 
+    BOOST_STATIC_ASSERT(decorator::is_op_of<
+        req_t, request_type>::value);
+
     struct res_t
     {
         bool pass_ = false;
@@ -68,6 +71,9 @@ public:
         }
     };
 
+    BOOST_STATIC_ASSERT(decorator::is_op_of<
+        res_t, response_type>::value);
+
     struct both_t : res_t , req_t
     {
         using req_t::operator();
@@ -115,14 +121,6 @@ public:
             decorator d3;
             d3 = std::move(d2);
         }
-
-        {
-            // this would be leaner with bind_front
-            decorator d(std::bind(
-                &decorator_test::dec_req, this,
-                    std::placeholders::_1));
-            BEAST_EXPECT(d.is_inline());
-        }
     }
 
     void