traits: add cpp file for testing instantiations

CMakeLists.txt

@@ -84,6 +84,7 @@ list (APPEND sources
     shader_module.hpp
     surface.cpp
     surface.hpp
+    traits.cpp
     traits.hpp
 )
 

traits.cpp

@@ -0,0 +1,21 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright:
+ *      2017, Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "./traits.hpp"
+
+
+///////////////////////////////////////////////////////////////////////////////