versioned interfaces

solanaceae/plugin/plugin_manager.hpp

@@ -10,20 +10,50 @@
 #include <string>
 
 // TODO: save plug name to instance
-extern std::map<std::string, void*> g_instance_map;
+// id -> version -> ptr
+extern std::map<std::string, std::map<std::string, void*>> g_instance_map;
 
 extern "C" {
 
-void* g_resolveInstance__internal(const char* id);
+void* g_resolveInstance__internal(const char* id, const char* version);
 
-void g_provideInstance__internal(const char* id, const char* plugin_name, void* instance);
+void g_provideInstance__internal(const char* id, const char* version, const char* plugin_name, void* instance);
 
 } // extern C
 
+namespace internal {
+	template<typename T>
+	class g_type_version {
+		typedef char yes[1];
+		typedef char no [2];
+
+		template<typename C> static yes& test_version(decltype(&C::version));
+		template<typename C> static no& test_version(...);
+
+		static bool const has_version = sizeof(test_version<T>(nullptr)) == sizeof(yes);
+		static constexpr const char* get_version(void) {
+			if constexpr (has_version) {
+				return T::version;
+			} else {
+				return "UNK"; // default version
+			}
+		}
+
+		public:
+			static constexpr const char* version = get_version();
+	};
+} // internal
+
+
 // templated helper, use or make sure vtable is right
+template<typename T>
+void g_provideInstance(const char* id, const char* version, const char* plugin_name, T* instance) {
+	g_provideInstance__internal(id, version, plugin_name, instance);
+}
+
 template<typename T>
 void g_provideInstance(const char* id, const char* plugin_name, T* instance) {
-	g_provideInstance__internal(id, plugin_name, instance);
+	g_provideInstance__internal(id, internal::g_type_version<T>::version, plugin_name, instance);
 }
 
 // only on host!