Merge pull request #205 from SylvainCorlay/double-crtp

No double CRTP

include/xwidgets/xobject.hpp

@@ -14,8 +14,6 @@
 #include "xtl/xoptional.hpp"
 #include "xtl/xjson.hpp"
 
-#include "xproperty/xobserved.hpp"
-
 #include "xmaterialize.hpp"
 #include "xtransport.hpp"
 
@@ -26,7 +24,7 @@ namespace xw
      ***********************/
 
     template <class D>
-    class xobject : public xp::xobserved<D>, public xtransport<D>
+    class xobject : public xtransport<D>
     {
     public:
 
@@ -45,18 +43,9 @@ namespace xw
         XPROPERTY(xtl::xoptional<std::string>, derived_type, _view_module_version, XWIDGETS_BASE_VERSION);
         XPROPERTY(xtl::xoptional<std::string>, derived_type, _view_name, "WidgetView");
 
-        using base_type::notify;
-
     protected:
 
-// MSVC wrongly raises compiler error C2385 over ambiguous call to constructor
-// without this workaround.
-#ifdef _MSC_VER
-        xobject();
-        xobject(xeus::xcomm&&, bool owning = false);
-#else
         using base_type::base_type;
-#endif
     };
 
     /**************************
@@ -84,20 +73,6 @@ namespace xw
         set_property_from_patch(_view_module_version, patch, buffers);
         set_property_from_patch(_view_name, patch, buffers);
     }
-
-#ifdef _MSC_VER
-    template <class D>
-    inline xobject<D>::xobject()
-        : base_type()
-    {
-    }
-
-    template <class D>
-    inline xobject<D>::xobject(xeus::xcomm&& com, bool owning)
-        : base_type(std::move(com), owning)
-    {
-    }
-#endif
 }
 
 #endif

include/xwidgets/xtransport.hpp

@@ -16,6 +16,8 @@
 #include "xeus/xcomm.hpp"
 #include "xeus/xinterpreter.hpp"
 
+#include "xproperty/xobserved.hpp"
+
 #include "xbinary.hpp"
 #include "xcommon.hpp"
 #include "xholder.hpp"
@@ -43,16 +45,15 @@ namespace xw
      **************************/
 
     template <class D>
-    class xtransport : public xcommon
+    class xtransport : public xcommon, public xp::xobserved<D>
     {
     public:
 
         using base_type = xcommon;
         using derived_type = D;
+        using observed_type = xp::xobserved<D>;
 
-        derived_type& derived_cast() & noexcept;
-        const derived_type& derived_cast() const & noexcept;
-        derived_type derived_cast() && noexcept;
+        using base_type::notify;
 
     protected:
 
@@ -94,7 +95,7 @@ namespace xw
 
     template <class D>
     inline xtransport<D>::xtransport()
-        : base_type()
+        : base_type(), observed_type()
     {
         this->comm().on_message(std::bind(&xtransport::handle_message, this, std::placeholders::_1));
         get_transport_registry().register_weak(this);
@@ -111,7 +112,7 @@ namespace xw
 
     template <class D>
     inline xtransport<D>::xtransport(xeus::xcomm&& comm, bool owning)
-        : xcommon(std::move(comm))
+        : xcommon(std::move(comm)), observed_type()
     {
         this->comm().on_message(std::bind(&xtransport::handle_message, this, std::placeholders::_1));
         if (!owning)
@@ -122,15 +123,15 @@ namespace xw
 
     template <class D>
     inline xtransport<D>::xtransport(const xtransport& other)
-        : xcommon(other)
+        : xcommon(other), observed_type()
     {
         this->comm().on_message(std::bind(&xtransport::handle_message, this, std::placeholders::_1));
         get_transport_registry().register_weak(this);
     }
 
     template <class D>
     inline xtransport<D>::xtransport(xtransport&& other)
-        : xcommon(std::move(other))
+        : xcommon(std::move(other)), observed_type()
     {
         this->comm().on_message(std::bind(&xtransport::handle_message, this, std::placeholders::_1));
         get_transport_registry().register_weak(this);  // Replacing the address of the moved transport with `this`.
@@ -156,31 +157,13 @@ namespace xw
         return *this;
     }
 
-    template <class D>
-    inline auto xtransport<D>::derived_cast() & noexcept -> derived_type&
-    {
-        return *static_cast<derived_type*>(this);
-    }
-
-    template <class D>
-    inline auto xtransport<D>::derived_cast() const & noexcept -> const derived_type&
-    {
-        return *static_cast<const derived_type*>(this);
-    }
-
-    template <class D>
-    inline auto xtransport<D>::derived_cast() && noexcept -> derived_type
-    {
-        return *static_cast<derived_type*>(this);
-    }
-
     template <class D>
     inline void xtransport<D>::open()
     {
         // serialize state
         nl::json state;
         xeus::buffer_sequence buffers;
-        derived_cast().serialize_state(state, buffers);
+        this->derived_cast().serialize_state(state, buffers);
 
         // open comm
         base_type::open(std::move(state), std::move(buffers));        
@@ -207,7 +190,7 @@ namespace xw
             this->hold() = std::addressof(message);;
             insert_buffer_paths(const_cast<nl::json&>(state), buffer_paths);
             /*D*/
-            derived_cast().apply_patch(state, buffers);
+            this->derived_cast().apply_patch(state, buffers);
             /*D*/
             this->hold() = nullptr;
         }
@@ -216,7 +199,7 @@ namespace xw
             nl::json state;
             xeus::buffer_sequence buffers;
             /*D*/
-            derived_cast().serialize_state(state, buffers);
+            this->derived_cast().serialize_state(state, buffers);
             /*D*/
             send_patch(std::move(state), std::move(buffers));
         }
@@ -226,7 +209,7 @@ namespace xw
             if (it != data.end())
             {
                 /*D*/
-                derived_cast().handle_custom_message(it.value());
+                this->derived_cast().handle_custom_message(it.value());
                 /*D*/
             }
         }