add observer_handler class

src/util/ObjectsKeeper.hpp

@@ -3,20 +3,39 @@
 #include <memory>
 #include <vector>
 
+#include "util/observer_handler.hpp"
+
 namespace util {
     /// @brief Keeps shared pointers alive until destruction
     class ObjectsKeeper {
         std::vector<std::shared_ptr<void>> ptrs;
+        std::vector<observer_handler> handlers;
     public:
+        ObjectsKeeper() = default;
+
+        ObjectsKeeper(const ObjectsKeeper&) = delete;
+
+        ObjectsKeeper(ObjectsKeeper&& keeper) noexcept
+            : ptrs(std::move(keeper.ptrs)),
+              handlers(std::move(keeper.handlers)) {
+        }
+
+        ObjectsKeeper& operator=(ObjectsKeeper&& keeper) noexcept = default;
+
         virtual ~ObjectsKeeper() {
         }
 
         virtual void keepAlive(std::shared_ptr<void> ptr) {
-            ptrs.push_back(ptr);
+            ptrs.push_back(std::move(ptr));
+        }
+
+        virtual void keepAlive(observer_handler&& ptr) {
+            handlers.emplace_back(std::move(ptr));
         }
 
         virtual void clearKeepedObjects() {
             ptrs.clear();
+            handlers.clear();
         }
     };
 }