ADD: added Catch2 test; added TrackClass

libs/Catch2/include/internal/catch_singletons.hpp

@@ -0,0 +1,44 @@
+/*
+ *  Created by Phil Nash on 15/6/2018.
+ *
+ *  Distributed under the Boost Software License, Version 1.0. (See accompanying
+ *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+ */
+#ifndef TWOBLUECUBES_CATCH_SINGLETONS_HPP_INCLUDED
+#define TWOBLUECUBES_CATCH_SINGLETONS_HPP_INCLUDED
+
+namespace Catch {
+
+    struct ISingleton {
+        virtual ~ISingleton();
+    };
+
+
+    void addSingleton( ISingleton* singleton );
+    void cleanupSingletons();
+
+
+    template<typename SingletonImplT, typename InterfaceT = SingletonImplT, typename MutableInterfaceT = InterfaceT>
+    class Singleton : SingletonImplT, public ISingleton {
+
+        static auto getInternal() -> Singleton* {
+            static Singleton* s_instance = nullptr;
+            if( !s_instance ) {
+                s_instance = new Singleton;
+                addSingleton( s_instance );
+            }
+            return s_instance;
+        }
+
+    public:
+        static auto get() -> InterfaceT const& {
+            return *getInternal();
+        }
+        static auto getMutable() -> MutableInterfaceT& {
+            return *getInternal();
+        }
+    };
+
+} // namespace Catch
+
+#endif // TWOBLUECUBES_CATCH_SINGLETONS_HPP_INCLUDED