added object_proxy as the holder of the object in object_ptr

include/matador/object/object_proxy.hpp

@@ -9,17 +9,33 @@ class basic_object_proxy {
 public:
     virtual ~basic_object_proxy() = default;
 
-    virtual void *get() const = 0;
+    [[nodiscard]] virtual void *get() const = 0;
 };
 
 template<class Type>
 class object_proxy : public basic_object_proxy {
 public:
-    void *get() const override { return static_cast<Type *>(this)->get(); }
+    object_proxy() = default;
+    explicit object_proxy(Type* obj)
+    : obj_(obj) {}
+    explicit object_proxy(std::unique_ptr<Type> obj)
+    : obj_(std::move(obj)) {}
+
+    [[nodiscard]] void *get() const override { return static_cast<void*>(obj_.get()); }
 
     Type* operator->() const { return obj_.get(); }
+    Type& operator*() { return *obj_; }
+    const Type& operator*() const { return *obj_; }
+
+    Type* pointer() const { return obj_.get(); }
+
+    Type& ref() { return *obj_; }
+    const Type& ref() const { return *obj_; }
+
+    void reset(Type* obj) { obj_.reset(obj); }
+
 private:
-    std::shared_ptr<Type> obj_{};
+    std::unique_ptr<Type> obj_{};
 };
 
 }