Add CRTP base class for the policies of the generic device

fairmq/devices/BaseSourcePolicy.h

@@ -0,0 +1,91 @@
+/* 
+ * File:   BaseSourcePolicy.h
+ * Author: winckler
+ *
+ * Created on October 14, 2015, 1:01 PM
+ */
+
+#ifndef BASESOURCEPOLICY_H
+#define	BASESOURCEPOLICY_H
+
+#include <type_traits>
+// c++11 code
+//  CRTP base class
+template <typename TDerived >
+class BaseSourcePolicy
+{
+public:
+    BaseSourcePolicy() 
+    {}
+
+    virtual ~BaseSourcePolicy()
+    {}
+
+    template<typename C = TDerived>
+    auto InitSource()-> decltype(static_cast<C*>(this)->InitSource() )
+    {
+        static_assert(std::is_same<C, TDerived>{}, "BaseSourcePolicy::InitSource hack broken");
+        return static_cast<TDerived*>(this)->InitSource();
+    }
+
+    template<typename C = TDerived>
+    int64_t GetNumberOfEvent()//-> decltype(static_cast<C*>(this)->GetNumberOfEvent() )
+    {
+        static_assert(std::is_same<C, TDerived>{}, "BaseSourcePolicy::GetNumberOfEvent hack broken");
+        return static_cast<TDerived*>(this)->GetNumberOfEvent();
+    }
+
+    template<typename C = TDerived>
+    auto SetIndex(int64_t eventIdx)-> decltype(static_cast<C*>(this)->SetIndex(eventIdx) )
+    {
+        static_assert(std::is_same<C, TDerived>{}, "BaseSourcePolicy::SetIndex hack broken");
+        return static_cast<TDerived*>(this)->SetIndex(eventIdx);
+    }
+
+    template<typename C = TDerived>
+    //auto GetOutData()-> decltype(static_cast<C*>(this)->GetOutData() )
+    decltype(std::declval<C*>()->GetOutData() ) GetOutData()
+    {
+        static_assert(std::is_same<C, TDerived>{}, "BaseSourcePolicy::GetOutData hack broken");
+        return static_cast<TDerived*>(this)->GetOutData();
+    }
+
+};
+
+/*
+// c++14 code
+//  CRTP base class
+template <typename TDerived >
+class BaseSourcePolicy
+{
+public:
+    BaseSourcePolicy() 
+    {}
+
+    virtual ~BaseSourcePolicy()
+    {}
+
+    auto InitSource()
+    {
+        return static_cast<TDerived*>(this)->InitSource();
+    }
+
+    int64_t GetNumberOfEvent()
+    {
+        return static_cast<TDerived*>(this)->GetNumberOfEvent();
+    }
+
+    auto SetIndex(int64_t eventIdx)
+    {
+        return static_cast<TDerived*>(this)->SetIndex(int64_t eventIdx);
+    }
+
+    auto GetOutData()
+    {
+        return static_cast<TDerived*>(this)->GetOutData();
+    }
+
+};
+*/
+#endif	/* BASESOURCEPOLICY_H */
+