refactored object_proxy and object_ptr and fixed their bugs

include/matador/object/object_ptr.hpp

@@ -17,68 +17,152 @@ inline constexpr null_object_ptr_t nullobj{};
 template <typename Type>
 class object_ptr {
 public:
-  object_ptr()
+object_ptr()
   : proxy_(std::make_shared<object_proxy<Type>>()) {}
+
   object_ptr(null_object_ptr_t) {}
+
   explicit object_ptr(std::shared_ptr<Type> obj)
-  : proxy_(std::make_shared<object_proxy<Type>>(obj)) {}
+  : proxy_(std::make_shared<object_proxy<Type>>(std::move(obj))) {}
+
   explicit object_ptr(std::shared_ptr<object_proxy<Type>> obj)
   : proxy_(std::move(obj)) {}
+
   object_ptr(const object_ptr &other) = default;
   object_ptr(object_ptr &&other) noexcept = default;
   object_ptr& operator=(const object_ptr &other) = default;
-  object_ptr& operator=(object_ptr &&other) = default;
+  object_ptr& operator=(object_ptr &&other) noexcept = default;
+
   object_ptr& operator=(null_object_ptr_t) {
     proxy_.reset();
     return *this;
   }
 
   bool operator==(const object_ptr &other) const {
-    return get() == other.get();
+    if (proxy_ == other.proxy_) {
+      return true;
+    }
+
+    if (!proxy_ || !other.proxy_) {
+      return false;
+    }
+
+    if (has_primary_key() && other.has_primary_key()) {
+      return primary_key() == other.primary_key();
+    }
+
+    return false;
   }
+
   bool operator==(null_object_ptr_t) const {
     return empty();
   }
+
   bool operator!=(const object_ptr &other) const { return !operator==(other); }
   bool operator!=(null_object_ptr_t) const { return !empty(); }
 
   using value_type = Type;
 
-  Type *operator->() const { return get(); }
-  Type &operator*() { return *get(); }
-  const Type &operator*() const { return *get(); }
+  Type *operator->() const {
+    return checked_get();
+  }
 
-  [[nodiscard]] bool empty() const { return get() == nullptr; }
+  Type &operator*() {
+    return *checked_get();
+  }
+
+  const Type &operator*() const {
+    return *checked_get();
+  }
+
+  [[nodiscard]] bool empty() const {
+    return proxy_ == nullptr || proxy_->empty();
+  }
 
   Type *get() const {
     return proxy_ ? proxy_->pointer() : nullptr;
   }
 
-  void reset() { proxy_.reset(); }
-  void reset(const std::shared_ptr<object_proxy<Type>>& proxy) { proxy_ = proxy; }
+  [[nodiscard]] std::shared_ptr<Type> object() const {
+    return proxy_ ? proxy_->object() : nullptr;
+  }
 
-  [[nodiscard]] std::shared_ptr<object_proxy<Type>> proxy() const { return proxy_; }
+  void reset() {
+    proxy_.reset();
+  }
 
-  operator bool() const { return valid(); }
-  [[nodiscard]] bool valid() const { return proxy_ != nullptr && !proxy_->empty(); }
+  void reset(std::shared_ptr<object_proxy<Type>> proxy) {
+    proxy_ = std::move(proxy);
+  }
 
-  [[nodiscard]] bool has_primary_key() const { return proxy_->has_primary_key(); }
-  [[nodiscard]] const utils::identifier &primary_key() const { return proxy_->primary_key(); }
-  void primary_key(const utils::identifier &pk) { proxy_->primary_key(pk); }
+  [[nodiscard]] std::shared_ptr<object_proxy<Type>> proxy() const {
+    return proxy_;
+  }
 
-  [[nodiscard]] bool is_persistent() const { return proxy_->is_persistent(); }
-  [[nodiscard]] bool is_transient() const { return proxy_->is_transient(); }
-  [[nodiscard]] bool is_detached() const { return proxy_->is_detached(); }
-  [[nodiscard]] bool is_removed() const { return proxy_->is_removed(); }
-  [[nodiscard]] bool is_state(const object_state state) const { return proxy_->is_state(state); }
+  explicit operator bool() const {
+    return valid();
+  }
+
+  [[nodiscard]] bool valid() const {
+    return proxy_ != nullptr && !proxy_->empty();
+  }
+
+  [[nodiscard]] bool has_primary_key() const {
+    return proxy_ != nullptr && proxy_->has_primary_key();
+  }
+
+  [[nodiscard]] utils::identifier primary_key() const {
+    return proxy_ ? proxy_->primary_key() : utils::identifier{};
+  }
+
+  void primary_key(const utils::identifier &pk) {
+    ensure_proxy();
+    proxy_->primary_key(pk);
+  }
+
+  [[nodiscard]] bool is_persistent() const {
+    return proxy_ != nullptr && proxy_->is_persistent();
+  }
+
+  [[nodiscard]] bool is_transient() const {
+    return proxy_ != nullptr && proxy_->is_transient();
+  }
+
+  [[nodiscard]] bool is_detached() const {
+    return proxy_ != nullptr && proxy_->is_detached();
+  }
+
+  [[nodiscard]] bool is_removed() const {
+    return proxy_ != nullptr && proxy_->is_removed();
+  }
+
+  [[nodiscard]] bool is_state(const object_state state) const {
+    return proxy_ != nullptr && proxy_->is_state(state);
+  }
 
   void change_state(object_state s) const {
     if (proxy_) {
       proxy_->change_state(s);
     }
   }
+
 private:
-  std::shared_ptr<object_proxy<Type> > proxy_{};
+  Type *checked_get() const {
+    auto *ptr = get();
+    if (!ptr) {
+      throw std::runtime_error("Cannot dereference empty object_ptr");
+    }
+    return ptr;
+  }
+
+  void ensure_proxy() {
+    if (!proxy_) {
+      proxy_ = std::make_shared<object_proxy<Type>>();
+    }
+  }
+
+private:
+  std::shared_ptr<object_proxy<Type>> proxy_{};
 };
 
 template<typename>