diff --git a/include/telebotxx/Attachment.hpp b/include/telebotxx/Attachment.hpp
index 86a8a54..4353de4 100644
--- a/include/telebotxx/Attachment.hpp
+++ b/include/telebotxx/Attachment.hpp
@@ -1,13 +1,133 @@
 #ifndef TELEBOTXX_ATTACHMENT_HPP
 #define TELEBOTXX_ATTACHMENT_HPP
 
+#include "Optional.hpp"
+
 #include <string>
-#include <ctime>
-#include <memory>
 #include <vector>
+#include <memory>
+#include <boost/variant/variant.hpp>
 
 namespace telebotxx {
 
+class PhotoSize
+{
+public:
+	PhotoSize();
+
+	const std::string& getFileId() const;
+	void setFileId(const std::string& fileId);
+
+	int getWidth() const;
+	void setWidth(int width);
+
+	int getHeight() const;
+	void setHeight(int height);
+
+	const optional<int>& getFileSize() const;
+	void setFileSize(optional<int> fileSize);
+
+private:
+	std::string fileId_;
+	int width_;
+	int height_;
+	optional<int> fileSize_;
+};
+
+using PhotoSizeArray = std::vector<PhotoSize>;
+
+class Audio
+{
+public:
+	Audio();
+
+	const std::string& getFileId() const;
+	void setFileId(const std::string& fileId);
+
+	int getDuration() const;
+	void setDuration(int duration);
+
+	const optional<std::string>& getPerformer() const;
+	void setPerformer(optional<std::string> performer);
+
+	const optional<std::string>& getTitle() const;
+	void setTitle(optional<std::string> title);
+
+	const optional<std::string>& getMimeType() const;
+	void setMimeType(optional<std::string> mimeType);
+
+	const optional<int>& getFileSize() const;
+	void setFileSize(optional<int> fileSize);
+
+private:
+	std::string fileId_;
+	int duration_;
+	optional<std::string> performer_;
+	optional<std::string> title_;
+	optional<std::string> mimeType_;
+	optional<int> fileSize_;
+};
+
+class Document
+{
+public:
+	Document();
+
+	const std::string& getFileId() const;
+	void setFileId(std::string fileId);
+
+	const optional<PhotoSize>& getThumb() const;
+	void setThumb(optional<PhotoSize> thumb);
+
+	const optional<std::string>& getFileName() const;
+	void setFileName(optional<std::string> fileName);
+
+	const optional<std::string>& getMimeType() const;
+	void setMimeType(optional<std::string> mimeType);
+
+	const optional<int>& getFileSize() const;
+	void setFileSize(optional<int> fileSize);
+
+private:
+	std::string fileId_;
+	optional<PhotoSize> thumb_;
+	optional<std::string> fileName_;
+	optional<std::string> mimeType_;
+	optional<int> fileSize_;
+};
+
+class Sticker
+{
+public:
+	Sticker();
+
+	const std::string& getFileId() const;
+	void setFileId(const std::string& fileId);
+
+	int getWidth() const;
+	void setWidth(int width);
+
+	int getHeight() const;
+	void setHeight(int height);
+
+	const optional<PhotoSize>& getThumb() const;
+	void setThumb(optional<PhotoSize> thumb);
+
+	const optional<std::string>& getEmoji() const;
+	void setEmoji(optional<std::string> emoji);
+
+	const optional<int>& getFileSize() const;
+	void setFileSize(optional<int> fileSize);
+
+private:
+	std::string fileId_;
+	int width_;
+	int height_;
+	optional<PhotoSize> thumb_;
+	optional<std::string> emoji_;
+	optional<int> fileSize_;
+};
+
 class Attachment
 {
 public:
@@ -25,194 +145,23 @@ public:
 		Venue
 	};
 
-	Attachment(Type type);
-	Attachment(const Attachment&);
-	Attachment(Attachment&&);
-	virtual ~Attachment() = 0;
+	Attachment(PhotoSizeArray);
+	Attachment(Audio);
+	Attachment(Document);
+	Attachment(Sticker);
 
 	Type getType() const;
 
-	void swap(Attachment& other) noexcept;
+	const PhotoSizeArray& getPhotoSizeArray() const;
+	const Audio& getAudio() const;
+	const Document& getDocument() const;
+	const Sticker& getSticker() const;
 
 private:
-	Type attachmentType_;
+	Type type_;
+	boost::variant<PhotoSizeArray, Audio, Document, Sticker> value_;
 };
 
-using AttachmentPtr = std::shared_ptr<Attachment>;
-
-class PhotoSize
-{
-public:
-	PhotoSize();
-	PhotoSize(const PhotoSize&);
-	PhotoSize(PhotoSize&&);
-	~PhotoSize();
-
-	const std::string& getFileId() const;
-	void setFileId(const std::string& fileId);
-
-	int getWidth() const;
-	void setWidth(int width);
-
-	int getHeight() const;
-	void setHeight(int height);
-
-	int getFileSize() const;
-	void setFileSize(int fileSize);
-
-	void swap(PhotoSize& other) noexcept;
-
-	const PhotoSize& operator=(PhotoSize other) noexcept;
-
-private:
-	std::string fileId_;
-	int width_;
-	int height_;
-	int fileSize_;
-};
-
-using PhotoSizePtr = std::shared_ptr<PhotoSize>;
-
-class PhotoSizeArray : public Attachment
-{
-public:
-	PhotoSizeArray();
-	PhotoSizeArray(const PhotoSizeArray&);
-	PhotoSizeArray(PhotoSizeArray&&);
-	~PhotoSizeArray();
-
-	const std::vector<PhotoSize>& getArray() const;
-	void setArray(const std::vector<PhotoSize>& array);
-
-	void swap(PhotoSizeArray& other) noexcept;
-
-	const PhotoSizeArray& operator=(PhotoSizeArray other) noexcept;
-
-private:
-	std::vector<PhotoSize> array_;
-};
-
-using PhotoSizeArrayPtr = std::shared_ptr<PhotoSizeArray>;
-
-class Audio : public Attachment
-{
-public:
-	Audio();
-	Audio(const Audio&);
-	Audio(Audio&&);
-	~Audio();
-
-	const std::string& getFileId() const;
-	void setFileId(const std::string& fileId);
-
-	int getDuration() const;
-	void setDuration(int duration);
-
-	const std::string& getPerformer() const;
-	void setPerformer(const std::string& performer);
-
-	const std::string& getTitle() const;
-	void setTitle(const std::string& title);
-
-	const std::string& getMimeType() const;
-	void setMimeType(const std::string& mimeType);
-
-	int getFileSize() const;
-	void setFileSize(int fileSize);
-
-	void swap(Audio& other) noexcept;
-
-	const Audio& operator=(Audio other) noexcept;
-
-private:
-	std::string fileId_;
-	int duration_;
-	std::string performer_;
-	std::string title_;
-	std::string mimeType_;
-	int fileSize_;
-};
-
-class Document : public Attachment
-{
-public:
-	Document();
-	Document(const Document&);
-	Document(Document&&);
-	~Document();
-
-	const std::string& getFileId() const;
-	void setFileId(const std::string& fileId);
-
-	const PhotoSizePtr getThumb() const;
-	void setThumb(const PhotoSizePtr& thumb);
-
-	const std::string& getFileName() const;
-	void setFileName(const std::string& fileName);
-
-	const std::string& getMimeType() const;
-	void setMimeType(const std::string& mimeType);
-
-	int getFileSize() const;
-	void setFileSize(int fileSize);
-
-	void swap(Document& other) noexcept;
-
-	const Document& operator=(Document other) noexcept;
-
-private:
-	std::string fileId_;
-	PhotoSizePtr thumb_;
-	std::string fileName_;
-	std::string mimeType_;
-	int fileSize_;
-};
-
-class Sticker : public Attachment
-{
-public:
-	Sticker();
-	Sticker(const Sticker&);
-	Sticker(Sticker&&);
-	~Sticker();
-
-	const std::string& getFileId() const;
-	void setFileId(const std::string& fileId);
-
-	int getWidth() const;
-	void setWidth(int width);
-
-	int getHeight() const;
-	void setHeight(int height);
-
-	const PhotoSizePtr getThumb() const;
-	void setThumb(const PhotoSizePtr& thumb);
-
-	const std::string& getEmoji() const;
-	void setEmoji(const std::string& emoji);
-
-	int getFileSize() const;
-	void setFileSize(int fileSize);
-
-	void swap(Sticker& other) noexcept;
-
-	const Sticker& operator=(Sticker other) noexcept;
-
-private:
-	std::string fileId_;
-	int width_;
-	int height_;
-	PhotoSizePtr thumb_;
-	std::string emoji_;
-	int fileSize_;
-};
-
-void swap(PhotoSize& lhs, PhotoSize& rhs);
-void swap(PhotoSizeArray& lhs, PhotoSizeArray& rhs);
-void swap(Audio& lhs, Audio& rhs);
-void swap(Document& lhs, Document& rhs);
-void swap(Sticker& lhs, Sticker& rhs);
-
 }
 
 #endif // TELEBOTXX_ATTACHMENT_HPP
diff --git a/include/telebotxx/Chat.hpp b/include/telebotxx/Chat.hpp
index 4939b7e..1a5091c 100644
--- a/include/telebotxx/Chat.hpp
+++ b/include/telebotxx/Chat.hpp
@@ -1,6 +1,8 @@
 #ifndef TELEBOTXX_CHAT_HPP
 #define TELEBOTXX_CHAT_HPP
 
+#include "Optional.hpp"
+
 #include <string>
 #include <memory>
 #include <cstdint>
@@ -19,9 +21,6 @@ public:
 	};
 
 	Chat();
-	Chat(const Chat&);
-	Chat(Chat&&);
-	~Chat();
 
 	std::int64_t getId() const;
 	void setId(std::int64_t id);
@@ -29,39 +28,31 @@ public:
 	Type getType() const;
 	void setType(Type type);
 
-	const std::string& getTitle() const;
-	void setTitle(const std::string& title);
+	const optional<std::string>& getTitle() const;
+	void setTitle(optional<std::string> title);
 
-	const std::string& getUsername() const;
-	void setUsername(const std::string& username);
+	const optional<std::string>& getUsername() const;
+	void setUsername(optional<std::string> username);
 
-	const std::string& getFirstName() const;
-	void setFirstName(const std::string& firstName);
+	const optional<std::string>& getFirstName() const;
+	void setFirstName(optional<std::string> firstName);
 
-	const std::string& getLastName() const;
-	void setLastName(const std::string& lastName);
+	const optional<std::string>& getLastName() const;
+	void setLastName(optional<std::string> lastName);
 
 	bool isAllAdmins() const;
 	void setAllAdmins(bool allAdmins);
 
-	void swap(Chat& other) noexcept;
-
-	const Chat& operator=(Chat other) noexcept;
-
 private:
 	std::int64_t id_;
 	Type type_;
-	std::string title_;
-	std::string username_;
-	std::string firstName_;
-	std::string lastName_;
+	optional<std::string> title_;
+	optional<std::string> username_;
+	optional<std::string> firstName_;
+	optional<std::string> lastName_;
 	bool allAdmins_;
 };
 
-using ChatPtr = std::shared_ptr<Chat>;
-
-void swap(Chat& lhs, Chat& rhs);
-
 Chat::Type chatTypeFromString(const std::string& str);
 
 }
diff --git a/include/telebotxx/Exception.hpp b/include/telebotxx/Exception.hpp
index 091491f..9a5a79f 100644
--- a/include/telebotxx/Exception.hpp
+++ b/include/telebotxx/Exception.hpp
@@ -17,8 +17,8 @@ public:
 class ApiError : public std::runtime_error
 {
 public:
-	ApiError(int code, const std::string& message)
-		: std::runtime_error(message), code_(code)
+	ApiError(int code, std::string message)
+		: std::runtime_error(std::move(message)), code_(code)
 	{
 	}
 
diff --git a/include/telebotxx/Message.hpp b/include/telebotxx/Message.hpp
index fdd235a..e461fc1 100644
--- a/include/telebotxx/Message.hpp
+++ b/include/telebotxx/Message.hpp
@@ -4,10 +4,12 @@
 #include "User.hpp"
 #include "Chat.hpp"
 #include "Attachment.hpp"
+#include "Optional.hpp"
 
 #include <vector>
 #include <ctime>
 #include <memory>
+#include <boost/variant/variant.hpp>
 
 namespace telebotxx {
 
@@ -30,9 +32,6 @@ public:
 	};
 
 	MessageEntity();
-	MessageEntity(const MessageEntity&);
-	MessageEntity(MessageEntity&&);
-	~MessageEntity();
 
 	Type getType() const;
 	void setType(Type type);
@@ -43,22 +42,18 @@ public:
 	size_t getLength() const;
 	void setLength(size_t length);
 
-	const std::string& getUrl() const;
-	void setUrl(const std::string& url);
+	const optional<std::string>& getUrl() const;
+	void setUrl(std::string url);
 
-	const User& getUser() const;
-	void setUser(const User& user);
-
-	void swap(MessageEntity& other) noexcept;
-
-	const MessageEntity& operator=(MessageEntity other);
+	const optional<User>& getUser() const;
+	void setUser(User user);
 
 private:
 	Type type_;
 	int offset_;
 	std::size_t length_;
-	std::string url_;
-	User user_;
+	optional<std::string> url_;
+	optional<User> user_;
 };
 
 MessageEntity::Type messageEntityTypeFromString(const std::string& str);
@@ -72,60 +67,57 @@ class Message
 {
 public:
 	Message();
-	Message(const Message&);
-	Message(Message&&);
-	~Message();
 
 	int getId() const;
 	void setId(int id);
 
-	const UserPtr getFrom() const;
-	void setFrom(UserPtr from);
+	const optional<User>& getFrom() const;
+	void setFrom(optional<User> from);
 
 	time_t getDate() const;
 	void setDate(time_t date);
 
 	const Chat& getChat() const;
-	void setChat(const Chat& chat);
+	void setChat(Chat chat);
 
-	const UserPtr getForwardFrom() const;
-	void setForwardFrom(UserPtr forwardFrom);
+	const optional<User>& getForwardFrom() const;
+	void setForwardFrom(optional<User> forwardFrom);
 
-	const ChatPtr getForwardFromChat() const;
-	void setForwardFromChat(ChatPtr forwardFromChat);
+	const optional<Chat>& getForwardFromChat() const;
+	void setForwardFromChat(optional<Chat> forwardFromChat);
 
-	time_t getForwardDate() const;
-	void setForwardDate(time_t forwardDate);
+	const optional<time_t>& getForwardDate() const;
+	void setForwardDate(optional<time_t> forwardDate);
 
-	const MessagePtr getReplyToMessage() const;
+	MessagePtr getReplyToMessage() const;
 	void setReplyToMessage(MessagePtr replyToMessage);
 
-	time_t getEditDate() const;
-	void setEditDate(time_t editDate);
+	const optional<time_t>& getEditDate() const;
+	void setEditDate(optional<time_t> editDate);
 
-	const std::string& getText() const;
-	void setText(const std::string& text);
+	const optional<std::string>& getText() const;
+	void setText(optional<std::string> text);
 
-	const MessageEntities& getEntities() const;
-	void setEntities(MessageEntities&& entities);
+	const optional<MessageEntities>& getEntities() const;
+	void setEntities(optional<MessageEntities> entities);
 
-	const AttachmentPtr getAttachment() const;
-	void setAttachment(AttachmentPtr attachment);
+	const optional<Attachment>& getAttachment() const;
+	void setAttachment(optional<Attachment> attachment);
 
-	const std::string& getCaption() const;
-	void setCaption(const std::string& caption);
+	const optional<std::string>& getCaption() const;
+	void setCaption(optional<std::string> caption);
 
-	const UserPtr getNewChatMember() const;
-	void setNewChatMember(UserPtr newChatMember);
+	const optional<User>& getNewChatMember() const;
+	void setNewChatMember(optional<User> newChatMember);
 
-	const UserPtr getLeftChatMember() const;
-	void setLeftChatMember(UserPtr leftChatMember);
+	const optional<User>& getLeftChatMember() const;
+	void setLeftChatMember(optional<User> leftChatMember);
 
-	const std::string& getNewChatTitle() const;
-	void setNewChatTitle(const std::string& newChatTitle);
+	const optional<std::string>& getNewChatTitle() const;
+	void setNewChatTitle(optional<std::string> newChatTitle);
 
-	const PhotoSizeArrayPtr getNewChatPhoto() const;
-	void setNewChatPhoto(PhotoSizeArrayPtr newChatPhoto);
+	const optional<PhotoSizeArray> getNewChatPhoto() const;
+	void setNewChatPhoto(optional<PhotoSizeArray> newChatPhoto);
 
 	bool isDeleteChatPhoto() const;
 	void setDeleteChatPhoto(bool deleteChatPhoto);
@@ -139,48 +131,43 @@ public:
 	bool isChannelChatCreated() const;
 	void setChannelChatCreated(bool channelChatCreated);
 
-	std::int64_t getMigrateToChatId() const;
-	void setMigrateToChatId(std::int64_t migrateToChatId);
+	const optional<std::int64_t>& getMigrateToChatId() const;
+	void setMigrateToChatId(optional<std::int64_t> migrateToChatId);
 
-	std::int64_t getMigrateFromChatId() const;
-	void setMigrateFromChatId(std::int64_t migrateFromChatId);
+	const optional<std::int64_t>& getMigrateFromChatId() const;
+	void setMigrateFromChatId(optional<std::int64_t> migrateFromChatId);
 
-	const MessagePtr getPinnedMessage() const;
+	MessagePtr getPinnedMessage() const;
 	void setPinnedMessage(MessagePtr pinnedMessage);
 
-	void swap(Message& other) noexcept;
-
-	const Message& operator=(Message other) noexcept;
-
 private:
 	int id_;
-	UserPtr from_;
+	optional<User> from_;
 	std::time_t date_;
 	Chat chat_;
-	UserPtr forwardFrom_;
-	ChatPtr forwardFromChat_;
-	std::time_t forwardDate_;
+	optional<User> forwardFrom_;
+	optional<Chat> forwardFromChat_;
+	optional<int> forwardFromMessageId_;
+	optional<std::time_t> forwardDate_;
 	MessagePtr replyToMessage_;
-	std::time_t editDate_;
-	std::string text_;
-	MessageEntities entities_;
-	AttachmentPtr attachment_;
-	std::string caption_;
-	UserPtr newChatMember_;
-	UserPtr leftChatMember_;
-	std::string newChatTitle_;
-	PhotoSizeArrayPtr newChatPhoto_;
+	optional<std::time_t> editDate_;
+	optional<std::string> text_;
+	optional<MessageEntities> entities_;
+	optional<Attachment> attachment_;
+	optional<std::string> caption_;
+	optional<User> newChatMember_;
+	optional<User> leftChatMember_;
+	optional<std::string> newChatTitle_;
+	optional<PhotoSizeArray> newChatPhoto_;
 	bool deleteChatPhoto_;
 	bool groupChatCreated_;
 	bool superGroupChatCreated_;
 	bool channelChatCreated_;
-	std::int64_t migrateToChatId_;
-	std::int64_t migrateFromChatId_;
+	optional<std::int64_t> migrateToChatId_;
+	optional<std::int64_t> migrateFromChatId_;
 	MessagePtr pinnedMessage_;
 };
 
-void swap(Message& lhs, Message& rhs);
-
 }
 
 #endif // TELEBOTXX_MESSAGE_HPP
diff --git a/include/telebotxx/Optional.hpp b/include/telebotxx/Optional.hpp
new file mode 100644
index 0000000..7512c34
--- /dev/null
+++ b/include/telebotxx/Optional.hpp
@@ -0,0 +1,15 @@
+#ifndef TELEBOTXX_OPTIONAL_HPP
+#define TELEBOTXX_OPTIONAL_HPP
+
+#include <boost/optional.hpp>
+
+namespace telebotxx {
+
+template <typename T>
+using optional = boost::optional<T>;
+
+const auto none = boost::none;
+
+}
+
+#endif // TELEBOTXX_OPTIONAL_HPP
diff --git a/include/telebotxx/RequestOptions.hpp b/include/telebotxx/RequestOptions.hpp
index 33bd2b7..d299b5f 100644
--- a/include/telebotxx/RequestOptions.hpp
+++ b/include/telebotxx/RequestOptions.hpp
@@ -31,9 +31,6 @@ class ChatId
 public:
 	ChatId(int);
 	ChatId(const std::string&);
-	ChatId(const ChatId&);
-	ChatId(ChatId&&);
-	~ChatId();
 
 	enum class Type { Id, Username };
 	Type getType() const;
@@ -92,9 +89,6 @@ public:
 	explicit Photo(const Buffer&);
 	explicit Photo(const File&);
 	explicit Photo(const Url&);
-	Photo(const Photo&);
-	Photo(Photo&&);
-	~Photo();
 
 	enum class Type	{ Id, Buffer, File, Url };
 	Type getType() const;
diff --git a/include/telebotxx/Update.hpp b/include/telebotxx/Update.hpp
index 0703021..f978f1a 100644
--- a/include/telebotxx/Update.hpp
+++ b/include/telebotxx/Update.hpp
@@ -14,55 +14,27 @@ public:
 	enum class Type
 	{
 		Message,
+		EditedMessage,
+		ChannelPost,
+		EditedChannelPost,
 		InlineQuery,
 		ChosenInlineResult,
 		CallbackQuery
 	};
 
-	Update(int id, Type type);
-	Update(const Update&);
-	Update(Update&&);
-	virtual ~Update() = 0;
+	Update(int id, Type type, std::unique_ptr<Message>);
 
 	int getId() const;
 	Type getType() const;
-
-	void swap(Update& other) noexcept;
+	MessagePtr getMessage() const;
 
 private:
 	int id_;
-	Type updateType_;
+	Type type_;
+	boost::variant<MessagePtr> value_;
 };
 
-using UpdatePtr = std::shared_ptr<Update>;
-using Updates = std::vector<UpdatePtr>;
-
-class MessageUpdate : public Update
-{
-public:
-	enum class MessageType
-	{
-		Message,
-		EditedMessage,
-		ChannelPost,
-		EditedChannelPost
-	};
-
-	MessageUpdate(int id, MessageType type, const Message& message);
-	MessageUpdate(const MessageUpdate&);
-	MessageUpdate(MessageUpdate&&);
-	~MessageUpdate();
-
-	MessageType getMessageType() const;
-	const Message& getMessage() const;
-
-	void swap(MessageUpdate& other) noexcept;
-	const MessageUpdate& operator=(MessageUpdate other);
-
-private:
-	MessageType type_;
-	Message message_;
-};
+using Updates = std::vector<Update>;
 
 }
 
diff --git a/include/telebotxx/User.hpp b/include/telebotxx/User.hpp
index a36ad83..06fb128 100644
--- a/include/telebotxx/User.hpp
+++ b/include/telebotxx/User.hpp
@@ -1,6 +1,7 @@
 #ifndef TELEBOTXX_USER_H
 #define TELEBOTXX_USER_H
 
+#include "Optional.hpp"
 #include <string>
 #include <memory>
 
@@ -10,9 +11,6 @@ class User
 {
 public:
 	User();
-	User(const User&);
-	User(User&&);
-	~User();
 
 	/// \brief Get id
 	int getId() const;
@@ -24,36 +22,30 @@ public:
 	const std::string& getFirstName() const;
 
 	/// \brief Set first name
-	void setFirstName(const std::string& firstName);
+	void setFirstName(std::string firstName);
 
 	/// \brief Get last name
-	const std::string& getLastName() const;
+	const optional<std::string>& getLastName() const;
 
 	/// \brief Set last name
-	void setLastName(const std::string& lastName);
+	void setLastName(optional<std::string> lastName);
 
 	/// \brief Get username
-	const std::string& getUsername() const;
+	const optional<std::string>& getUsername() const;
 
 	/// \brief Set username
-	void setUsername(const std::string& username);
+	void setUsername(optional<std::string> username);
 
 	/// \brief Get string representation of user
 	const std::string toString() const;
 
-	void swap(User&) noexcept;
-
-	const User& operator=(User other);
-
 private:
 	int id_;
 	std::string firstName_;
-	std::string lastName_;
-	std::string username_;
+	optional<std::string> lastName_;
+	optional<std::string> username_;
 };
 
-using UserPtr = std::shared_ptr<User>;
-
 std::ostream& operator<<(std::ostream& os, const User& user);
 
 }
diff --git a/src/Attachment.cpp b/src/Attachment.cpp
index 66b391b..cb18aca 100644
--- a/src/Attachment.cpp
+++ b/src/Attachment.cpp
@@ -1,30 +1,9 @@
 #include <telebotxx/Attachment.hpp>
 
+#include <boost/variant.hpp>
+
 namespace telebotxx {
 
-Attachment::Attachment(Type type)
-	: attachmentType_(type)
-{
-}
-
-Attachment::Attachment(const Attachment&) = default;
-
-Attachment::Attachment(Attachment&&) = default;
-
-Attachment::~Attachment() = default;
-
-Attachment::Type Attachment::getType() const
-{
-	return attachmentType_;
-}
-
-void Attachment::swap(Attachment& other) noexcept
-{
-	std::swap(attachmentType_, other.attachmentType_);
-}
-
-////////////////////////////////////////////////////////////////
-
 PhotoSize::PhotoSize()
 	: width_(-1),
 	  height_(-1),
@@ -32,12 +11,6 @@ PhotoSize::PhotoSize()
 {
 }
 
-PhotoSize::PhotoSize(const PhotoSize&) = default;
-
-PhotoSize::PhotoSize(PhotoSize&&) = default;
-
-PhotoSize::~PhotoSize() = default;
-
 const std::string& PhotoSize::getFileId() const
 {
 	return fileId_;
@@ -68,81 +41,24 @@ void PhotoSize::setHeight(int height)
 	height_ = height;
 }
 
-int PhotoSize::getFileSize() const
+const optional<int>& PhotoSize::getFileSize() const
 {
 	return fileSize_;
 }
 
-void PhotoSize::setFileSize(int fileSize)
+void PhotoSize::setFileSize(optional<int> fileSize)
 {
 	fileSize_ = fileSize;
 }
 
-void PhotoSize::swap(PhotoSize& other) noexcept
-{
-	using std::swap;
-	swap(fileId_, other.fileId_);
-	swap(width_, other.width_);
-	swap(height_, other.height_);
-	swap(fileSize_, other.fileSize_);
-}
-
-const PhotoSize& PhotoSize::operator=(PhotoSize other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
-////////////////////////////////////////////////////////////////
-
-PhotoSizeArray::PhotoSizeArray()
-	: Attachment(Attachment::Type::PhotoSizeArray)
-{
-}
-
-PhotoSizeArray::PhotoSizeArray(const PhotoSizeArray&) = default;
-
-PhotoSizeArray::PhotoSizeArray(PhotoSizeArray&&) = default;
-
-PhotoSizeArray::~PhotoSizeArray() = default;
-
-const std::vector<PhotoSize>& PhotoSizeArray::getArray() const
-{
-	return array_;
-}
-
-void PhotoSizeArray::setArray(const std::vector<PhotoSize>& array)
-{
-	array_ = array;
-}
-
-void PhotoSizeArray::swap(PhotoSizeArray& other) noexcept
-{
-	using std::swap;
-	swap(array_, other.array_);
-}
-
-const PhotoSizeArray& PhotoSizeArray::operator=(PhotoSizeArray other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
 ////////////////////////////////////////////////////////////////
 
 Audio::Audio()
-	: Attachment(Type::Audio),
-	  duration_(-1),
+	: duration_(-1),
 	  fileSize_(-1)
 {
 }
 
-Audio::Audio(const Audio&) = default;
-
-Audio::Audio(Audio&&) = default;
-
-Audio::~Audio() = default;
-
 const std::string& Audio::getFileId() const
 {
 	return fileId_;
@@ -163,159 +79,110 @@ void Audio::setDuration(int duration)
 	duration_ = duration;
 }
 
-const std::string& Audio::getPerformer() const
+const optional<std::string>& Audio::getPerformer() const
 {
 	return performer_;
 }
 
-void Audio::setPerformer(const std::string& performer)
+void Audio::setPerformer(optional<std::string> performer)
 {
-	performer_ = performer;
+	performer_ = std::move(performer);
 }
 
-const std::string& Audio::getTitle() const
+const optional<std::string>& Audio::getTitle() const
 {
 	return title_;
 }
 
-void Audio::setTitle(const std::string& title)
+void Audio::setTitle(optional<std::string> title)
 {
 	title_ = title;
 }
 
-const std::string& Audio::getMimeType() const
+const optional<std::string>& Audio::getMimeType() const
 {
 	return mimeType_;
 }
 
-void Audio::setMimeType(const std::string& mimeType)
+void Audio::setMimeType(optional<std::string> mimeType)
 {
 	mimeType_ = mimeType;
 }
 
-int Audio::getFileSize() const
+const optional<int>& Audio::getFileSize() const
 {
 	return fileSize_;
 }
 
-void Audio::setFileSize(int fileSize)
+void Audio::setFileSize(optional<int> fileSize)
 {
 	fileSize_ = fileSize;
 }
 
-void Audio::swap(Audio& other) noexcept
-{
-	Attachment::swap(other);
-	using std::swap;
-	swap(fileId_, other.fileId_);
-	swap(duration_, other.duration_);
-	swap(performer_, other.performer_);
-	swap(title_, other.title_);
-	swap(mimeType_, other.mimeType_);
-	swap(fileSize_, other.fileSize_);
-}
-
-const Audio& Audio::operator=(Audio other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
 ////////////////////////////////////////////////////////////////
 
 Document::Document()
-	: Attachment(Type::Document),
-	  fileSize_(-1)
+	: fileSize_(-1)
 {
 }
 
-Document::Document(const Document&) = default;
-
-Document::Document(Document&&) = default;
-
-Document::~Document() = default;
-
 const std::string& Document::getFileId() const
 {
 	return fileId_;
 }
 
-void Document::setFileId(const std::string& fileId)
+void Document::setFileId(std::string fileId)
 {
 	fileId_ = fileId;
 }
 
-const PhotoSizePtr Document::getThumb() const
+const optional<PhotoSize>& Document::getThumb() const
 {
 	return thumb_;
 }
 
-void Document::setThumb(const PhotoSizePtr& thumb)
+void Document::setThumb(optional<PhotoSize> thumb)
 {
 	thumb_ = thumb;
 }
 
-const std::string& Document::getFileName() const
+const optional<std::string>& Document::getFileName() const
 {
 	return fileName_;
 }
 
-void Document::setFileName(const std::string& fileName)
+void Document::setFileName(optional<std::string> fileName)
 {
 	fileName_ = fileName;
 }
 
-const std::string& Document::getMimeType() const
+const optional<std::string>& Document::getMimeType() const
 {
 	return mimeType_;
 }
 
-void Document::setMimeType(const std::string& mimeType)
+void Document::setMimeType(optional<std::string> mimeType)
 {
 	mimeType_ = mimeType;
 }
 
-int Document::getFileSize() const
+const optional<int>& Document::getFileSize() const
 {
 	return fileSize_;
 }
 
-void Document::setFileSize(int fileSize)
+void Document::setFileSize(optional<int> fileSize)
 {
 	fileSize_ = fileSize;
 }
 
-void Document::swap(Document& other) noexcept
-{
-	Attachment::swap(other);
-	using std::swap;
-	swap(fileId_, other.fileId_);
-	swap(thumb_, other.thumb_);
-	swap(fileName_, other.fileName_);
-	swap(mimeType_, other.mimeType_);
-	swap(fileSize_, other.fileSize_);
-}
-
-const Document& Document::operator=(Document other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
 ////////////////////////////////////////////////////////////////
 
 Sticker::Sticker()
-	: Attachment(Type::Sticker),
-	  fileSize_(-1)
+	: fileSize_(-1)
 {
 }
 
-Sticker::Sticker(const Sticker&) = default;
-
-Sticker::Sticker(Sticker&&) = default;
-
-Sticker::~Sticker() = default;
-
 const std::string& Sticker::getFileId() const
 {
 	return fileId_;
@@ -346,79 +213,81 @@ void Sticker::setHeight(int height)
 	height_ = height;
 }
 
-const PhotoSizePtr Sticker::getThumb() const
+const optional<PhotoSize>& Sticker::getThumb() const
 {
 	return thumb_;
 }
 
-void Sticker::setThumb(const PhotoSizePtr& thumb)
+void Sticker::setThumb(optional<PhotoSize> thumb)
 {
 	thumb_ = thumb;
 }
 
-const std::string& Sticker::getEmoji() const
+const optional<std::string>& Sticker::getEmoji() const
 {
 	return emoji_;
 }
 
-void Sticker::setEmoji(const std::string& emoji)
+void Sticker::setEmoji(optional<std::string> emoji)
 {
 	emoji_ = emoji;
 }
 
-int Sticker::getFileSize() const
+const optional<int>& Sticker::getFileSize() const
 {
 	return fileSize_;
 }
 
-void Sticker::setFileSize(int fileSize)
+void Sticker::setFileSize(optional<int> fileSize)
 {
 	fileSize_ = fileSize;
 }
 
-void Sticker::swap(Sticker& other) noexcept
-{
-	Attachment::swap(other);
-	using std::swap;
-	swap(fileId_, other.fileId_);
-	swap(width_, other.width_);
-	swap(height_, other.height_);
-	swap(thumb_, other.thumb_);
-	swap(emoji_, other.emoji_);
-	swap(fileSize_, other.fileSize_);
-}
-
-const Sticker& Sticker::operator=(Sticker other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
 ////////////////////////////////////////////////////////////////
 
-void swap(PhotoSize& lhs, PhotoSize& rhs)
+Attachment::Attachment(PhotoSizeArray photos)
+	: type_(Type::PhotoSizeArray), value_(std::move(photos))
 {
-	lhs.swap(rhs);
 }
 
-void swap(PhotoSizeArray& lhs, PhotoSizeArray& rhs)
+Attachment::Attachment(Audio audio)
+	: type_(Type::Audio), value_(std::move(audio))
 {
-	lhs.swap(rhs);
 }
 
-void swap(Audio& lhs, Audio& rhs)
+Attachment::Attachment(Document document)
+	: type_(Type::Document), value_(std::move(document))
 {
-	lhs.swap(rhs);
 }
 
-void swap(Document& lhs, Document& rhs)
+Attachment::Attachment(Sticker sticker)
+	: type_(Type::Sticker), value_(std::move(sticker))
 {
-	lhs.swap(rhs);
 }
 
-void swap(Sticker& lhs, Sticker& rhs)
+Attachment::Type Attachment::getType() const
 {
-	lhs.swap(rhs);
+	return type_;
+}
+
+const PhotoSizeArray& Attachment::getPhotoSizeArray() const
+{
+	return boost::get<PhotoSizeArray>(value_);
+}
+
+const Audio& Attachment::getAudio() const
+{
+	return boost::get<Audio>(value_);;
+}
+
+const Document& Attachment::getDocument() const
+{
+	return boost::get<Document>(value_);
+}
+
+const Sticker& Attachment::getSticker() const
+{
+	return boost::get<Sticker>(value_);;
 }
 
 }
diff --git a/src/BotApi.cpp b/src/BotApi.cpp
index 03823d7..a49d15d 100644
--- a/src/BotApi.cpp
+++ b/src/BotApi.cpp
@@ -34,7 +34,7 @@ public:
 		doc.Parse(response.c_str());
 
 		checkResponse(doc);
-		return *parseUser(doc, "result", REQUIRED);
+		return require<User>(doc, "result");
 	}
 
 	inline Message sendPhoto(const std::string& chat, const std::string& filename, const std::string& caption)
@@ -133,7 +133,7 @@ public:
 		doc.Parse(response.c_str());
 
 		checkResponse(doc);
-		return *parseUpdates(doc, "result", REQUIRED);
+		return parseUpdates(doc, "result");
 	}
 
 	std::string getTelegramMainUrl() const
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 962f235..f8c2f7b 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -5,7 +5,7 @@ message(STATUS "Configuring telebotxx")
 include(${CMAKE_SOURCE_DIR}/cmake/RequireCXX14.cmake)
 RequireCXX14()
 
-find_package(Boost REQUIRED)
+find_package(Boost 1.56 REQUIRED)
 include_directories(${Boost_INCLUDE_DIRS})
 
 # Add required compiler flags
diff --git a/src/Chat.cpp b/src/Chat.cpp
index f2753c6..6cfdef9 100644
--- a/src/Chat.cpp
+++ b/src/Chat.cpp
@@ -10,12 +10,6 @@ Chat::Chat()
 {
 }
 
-Chat::Chat(const Chat&) = default;
-
-Chat::Chat(Chat&&) = default;
-
-Chat::~Chat() = default;
-
 std::int64_t Chat::getId() const
 {
 	return id_;
@@ -36,42 +30,42 @@ void Chat::setType(Chat::Type type)
 	type_ = type;
 }
 
-const std::string& Chat::getTitle() const
+const optional<std::string>& Chat::getTitle() const
 {
 	return title_;
 }
 
-void Chat::setTitle(const std::string& title)
+void Chat::setTitle(optional<std::string> title)
 {
 	title_ = title;
 }
 
-const std::string& Chat::getUsername() const
+const optional<std::string>& Chat::getUsername() const
 {
 	return username_;
 }
 
-void Chat::setUsername(const std::string& username)
+void Chat::setUsername(optional<std::string> username)
 {
 	username_ = username;
 }
 
-const std::string& Chat::getFirstName() const
+const optional<std::string>& Chat::getFirstName() const
 {
 	return firstName_;
 }
 
-void Chat::setFirstName(const std::string& firstName)
+void Chat::setFirstName(optional<std::string> firstName)
 {
 	firstName_ = firstName;
 }
 
-const std::string& Chat::getLastName() const
+const optional<std::string>& Chat::getLastName() const
 {
 	return lastName_;
 }
 
-void Chat::setLastName(const std::string& lastName)
+void Chat::setLastName(optional<std::string> lastName)
 {
 	lastName_ = lastName;
 }
@@ -86,29 +80,6 @@ void Chat::setAllAdmins(bool allAdmins)
 	allAdmins_ = allAdmins;
 }
 
-void Chat::swap(Chat& other) noexcept
-{
-	using std::swap;
-	swap(id_, other.id_);
-	swap(type_, other.type_);
-	swap(title_, other.title_);
-	swap(username_, other.username_);
-	swap(firstName_, other.firstName_);
-	swap(lastName_, other.lastName_);
-	swap(allAdmins_, other.allAdmins_);
-}
-
-const Chat& Chat::operator=(Chat other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
-void swap(Chat& lhs, Chat& rhs)
-{
-	lhs.swap(rhs);
-}
-
 Chat::Type chatTypeFromString(const std::string& str)
 {
 	if (str == "private")
diff --git a/src/JsonObjects.cpp b/src/JsonObjects.cpp
index 00fe82f..890f103 100644
--- a/src/JsonObjects.cpp
+++ b/src/JsonObjects.cpp
@@ -1,45 +1,27 @@
 #include "JsonObjects.hpp"
-#include <telebotxx/Exception.hpp>
 
 #include <cstdint>
 
 namespace telebotxx {
 namespace impl {
-
-template<typename T> bool is(const rapidjson::Value& obj);
 template<> bool is<int>(const rapidjson::Value& obj) { return obj.IsInt(); }
 template<> bool is<std::int64_t>(const rapidjson::Value& obj) { return obj.IsInt64(); }
 template<> bool is<bool>(const rapidjson::Value& obj) { return obj.IsBool(); }
 template<> bool is<std::string>(const rapidjson::Value& obj) { return obj.IsString(); }
 
-template<typename T> const T get(const rapidjson::Value& obj);
 template<> const int get(const rapidjson::Value& obj) { return obj.GetInt(); }
 template<> const std::int64_t get(const rapidjson::Value& obj) { return obj.GetInt64(); }
 template<> const bool get(const rapidjson::Value& obj) { return obj.GetBool(); }
 template<> const std::string get(const rapidjson::Value& obj) { return obj.GetString(); }
 
-template<typename T> const T null();
-template<> const int null() { return 0; }
-template<> const std::int64_t null() { return 0; }
-template<> const bool null() { return false; }
-template<> const std::string null() { return ""; }
-
 }
 
-template<typename T>
-const T parse(const rapidjson::Value& obj, const char* name, bool required)
+bool check(const rapidjson::Value& obj, const char* name)
 {
-	if (obj.HasMember(name))
-	{
-		if (impl::is<T>(obj[name]))
-			return impl::get<T>(obj[name]);
-		else
-			throw ParseError(std::string("Field '") + name + "' has invalid type");
-	}
-	else if (required)
-		throw ParseError(std::string("Field '") + name + "' not found");
+	if (auto value = parse<bool>(obj, name, OPTIONAL))
+		return *value;
 	else
-		return impl::null<T>();
+		return false;
 }
 
 const rapidjson::Value& parseObject(const rapidjson::Value& parent, const char* name, bool required, bool& found)
@@ -84,220 +66,218 @@ const rapidjson::Value& parseArray(const rapidjson::Value& parent, const char* n
 	}
 }
 
-std::unique_ptr<PhotoSize> parsePhotoSize(const rapidjson::Value& obj)
-{
-	auto photo = std::make_unique<PhotoSize>();
-	photo->setFileId(parse<std::string>(obj, "file_id", REQUIRED));
-	photo->setWidth(parse<int>(obj, "width", REQUIRED));
-	photo->setHeight(parse<int>(obj, "height", REQUIRED));
-	photo->setFileSize(parse<int>(obj, "file_size", OPTIONAL));
-	return photo;
-}
-
-std::unique_ptr<PhotoSize> parsePhotoSize(const rapidjson::Value& parent, const char* name, bool required)
+template <>
+optional<Chat> parse<Chat>(const rapidjson::Value& parent, const char* name, bool required)
 {
+	optional<Chat> chat;
 	bool found;
 	auto& obj = parseObject(parent, name, required, found);
 	if (found)
 	{
-		return parsePhotoSize(obj);
+		chat.emplace();
+		chat->setId(require<std::int64_t>(obj, "id"));
+		chat->setType(chatTypeFromString(require<std::string>(obj, "type")));
+		chat->setTitle(allow<std::string>(obj, "title"));
+		chat->setUsername(parse<std::string>(obj, "username", OPTIONAL));
+		chat->setFirstName(parse<std::string>(obj, "first_name", OPTIONAL));
+		chat->setLastName(parse<std::string>(obj, "last_name", OPTIONAL));
+		chat->setAllAdmins(check(obj, "all_members_are_administrators"));
 	}
-	else
-		return nullptr;
+	return chat;
 }
 
-std::unique_ptr<PhotoSizeArray> parsePhotoSizeArray(const rapidjson::Value& parent, const char* name, bool required)
+template <>
+optional<User> parse<User>(const rapidjson::Value& parent, const char* name, bool required)
 {
+	optional<User> user;
+	bool found;
+	auto& obj = parseObject(parent, name, required, found);
+	if (found)
+	{
+		user.emplace();
+		user->setId(require<int>(obj, "id"));
+		user->setFirstName(require<std::string>(obj, "first_name"));
+		user->setLastName(allow<std::string>(obj, "last_name"));
+	}
+	return user;
+}
+
+PhotoSize parsePhotoSize(const rapidjson::Value& obj)
+{
+	PhotoSize photo;
+	photo.setFileId(require<std::string>(obj, "file_id"));
+	photo.setWidth(require<int>(obj, "width"));
+	photo.setHeight(require<int>(obj, "height"));
+	photo.setFileSize(allow<int>(obj, "file_size"));
+	return photo;
+}
+
+template <>
+optional<PhotoSize> parse<PhotoSize>(const rapidjson::Value& parent, const char* name, bool required)
+{
+	optional<PhotoSize> photo;
+	bool found;
+	auto& obj = parseObject(parent, name, required, found);
+	if (found)
+	{
+		photo.emplace(parsePhotoSize(obj));
+	}
+	return photo;
+}
+
+template <>
+optional<PhotoSizeArray> parse<PhotoSizeArray>(const rapidjson::Value& parent, const char* name, bool required)
+{
+	optional<PhotoSizeArray> photos;
 	bool found;
 	auto& obj = parseArray(parent, name, required, found);
 	if (found)
 	{
-		std::vector<PhotoSize> photos;
+		photos.emplace();
+		photos->reserve(obj.GetArray().Size());
 		for (auto& elem : obj.GetArray())
-		{
-			auto photo = parsePhotoSize(elem);
-			photos.push_back(std::move(*photo));
-		}
-		auto result = std::make_unique<PhotoSizeArray>();
-		result->setArray(photos);
-		return result;
+			photos->emplace_back(parsePhotoSize(elem));
 	}
-	else
-		return nullptr;
+	return photos;
 }
 
-std::unique_ptr<Audio> parseAudio(const rapidjson::Value& parent, const char* name, bool required)
+template <>
+optional<Audio> parse<Audio>(const rapidjson::Value& parent, const char* name, bool required)
 {
+	optional<Audio> audio;
 	bool found;
 	auto& obj = parseObject(parent, name, required, found);
 	if (found)
 	{
-		auto audio = std::make_unique<Audio>();
-		audio->setFileId(parse<std::string>(obj, "file_id", REQUIRED));
-		audio->setDuration(parse<int>(obj, "duration", REQUIRED));
-		audio->setPerformer(parse<std::string>(obj, "performer", OPTIONAL));
-		audio->setTitle(parse<std::string>(obj, "title", OPTIONAL));
-		audio->setMimeType(parse<std::string>(obj, "mime_type", OPTIONAL));
-		audio->setFileSize(parse<int>(obj, "file_size", OPTIONAL));
-		return audio;
+		audio->setFileId(require<std::string>(obj, "file_id"));
+		audio->setDuration(require<int>(obj, "duration"));
+		audio->setPerformer(allow<std::string>(obj, "performer"));
+		audio->setTitle(allow<std::string>(obj, "title"));
+		audio->setMimeType(allow<std::string>(obj, "mime_type"));
+		audio->setFileSize(allow<int>(obj, "file_size"));
 	}
-	else
-		return nullptr;
+	return audio;
 }
 
-std::unique_ptr<Document> parseDocument(const rapidjson::Value& parent, const char* name, bool required)
+template <>
+optional<Document> parse<Document>(const rapidjson::Value& parent, const char* name, bool required)
 {
+	optional<Document> document;
 	bool found;
 	auto& obj = parseObject(parent, name, required, found);
 	if (found)
 	{
-		auto document = std::make_unique<Document>();
-		document->setFileId(parse<std::string>(obj, "file_id", REQUIRED));
-		document->setThumb(parsePhotoSize(obj, "thumb", OPTIONAL));
-		document->setFileName(parse<std::string>(obj, "file_name", OPTIONAL));
-		document->setMimeType(parse<std::string>(obj, "mime_type", OPTIONAL));
-		document->setFileSize(parse<int>(obj, "file_size", OPTIONAL));
-		return document;
+		document.emplace();
+		document->setFileId(require<std::string>(obj, "file_id"));
+		document->setThumb(allow<PhotoSize>(obj, "thumb"));
+		document->setFileName(allow<std::string>(obj, "file_name"));
+		document->setMimeType(allow<std::string>(obj, "mime_type"));
+		document->setFileSize(allow<int>(obj, "file_size"));
 	}
-	else
-		return nullptr;
+	return document;
 }
 
-std::unique_ptr<Sticker> parseSticker(const rapidjson::Value& parent, const char* name, bool required)
+template <>
+optional<Sticker> parse<Sticker>(const rapidjson::Value& parent, const char* name, bool required)
 {
+	optional<Sticker> sticker;
 	bool found;
 	auto& obj = parseObject(parent, name, required, found);
 	if (found)
 	{
-		auto sticker = std::make_unique<Sticker>();
-		sticker->setFileId(parse<std::string>(obj, "file_id", REQUIRED));
-		sticker->setWidth(parse<int>(obj, "width", REQUIRED));
-		sticker->setHeight(parse<int>(obj, "height", REQUIRED));
-		sticker->setThumb(parsePhotoSize(obj, "thumb", OPTIONAL));
-		sticker->setEmoji(parse<std::string>(obj, "emoji", OPTIONAL));
-		sticker->setFileSize(parse<int>(obj, "file_size", OPTIONAL));
-		return sticker;
+		sticker.emplace();
+		sticker->setFileId(require<std::string>(obj, "file_id"));
+		sticker->setWidth(require<int>(obj, "width"));
+		sticker->setHeight(require<int>(obj, "height"));
+		sticker->setThumb(allow<PhotoSize>(obj, "thumb"));
+		sticker->setEmoji(allow<std::string>(obj, "emoji"));
+		sticker->setFileSize(allow<int>(obj, "file_size"));
 	}
-	else
-		return nullptr;
+	return sticker;
+}
+
+template <>
+optional<Attachment> parse<Attachment>(const rapidjson::Value& parent, const char* name, bool required)
+{
+	optional<Attachment> attachment;
+	if (auto photo = allow<PhotoSizeArray>(parent, "photo"))
+		attachment.emplace(std::move(*photo));
+	else if (auto audio = allow<Audio>(parent, "audio"))
+		attachment.emplace(std::move(*audio));
+	else if (auto document = allow<Document>(parent, "document"))
+		attachment.emplace(std::move(*document));
+	else if (auto sticker = allow<Sticker>(parent, "sticker"))
+		attachment.emplace(std::move(*sticker));
+	/// \todo Other attachments
+	return attachment;
 }
 
 std::unique_ptr<Message> parseMessage(const rapidjson::Value& parent, const char* name, bool required)
 {
+	std::unique_ptr<Message> message;
 	bool found;
 	auto& obj = parseObject(parent, name, required, found);
 	if (found)
 	{
-		auto message = std::make_unique<Message>();
-
-		message->setId(parse<int>(obj, "message_id", REQUIRED));
-		message->setFrom(parseUser(obj, "from", OPTIONAL));
-		message->setDate(parse<int>(obj, "date", REQUIRED));
-		message->setChat(*parseChat(obj, "chat", REQUIRED));
-		message->setForwardFrom(parseUser(obj, "forward_from", OPTIONAL));
-		message->setForwardFromChat(parseChat(obj, "forward_from_chat", OPTIONAL));
-		message->setForwardDate(parse<int>(obj, "forward_date", OPTIONAL));
+		message = std::make_unique<Message>();
+		message->setId(require<int>(obj, "message_id"));
+		message->setFrom(allow<User>(obj, "from"));
+		message->setDate(require<int>(obj, "date"));
+		message->setChat(require<Chat>(obj, "chat"));
+		message->setForwardFrom(allow<User>(obj, "forward_from"));
+		message->setForwardFromChat(allow<Chat>(obj, "forward_from_chat"));
+		message->setForwardDate(allow<std::int64_t>(obj, "forward_date"));
 		message->setReplyToMessage(parseMessage(obj, "reply_to_message", OPTIONAL));
-		message->setEditDate(parse<int>(obj, "edit_date", OPTIONAL));
+		message->setEditDate(allow<std::int64_t>(obj, "edit_date"));
 		message->setText(parse<std::string>(obj, "text", OPTIONAL));
 		//message->setEntities(parseEntities(obj, "entities", OPTIONAL));
-
-		/// \todo: Parse one of the possible attachments
-		std::shared_ptr<Attachment> attachment;
-		if (!(attachment = parsePhotoSizeArray(obj, "photo", OPTIONAL)))
-			if (!(attachment = parseAudio(obj, "audio", OPTIONAL)))
-				if (!(attachment = parseDocument(obj, "document", OPTIONAL)))
-					attachment = parseSticker(obj, "sticker", OPTIONAL);
-		message->setAttachment(attachment);
-
-		message->setCaption(parse<std::string>(obj, "caption", OPTIONAL));
-		message->setNewChatMember(parseUser(obj, "new_chat_member", OPTIONAL));
-		message->setLeftChatMember(parseUser(obj, "left_chat_member", OPTIONAL));
-		message->setNewChatTitle(parse<std::string>(obj, "new_chat_title", OPTIONAL));
-		message->setNewChatPhoto(parsePhotoSizeArray(obj, "new_chat_photo", OPTIONAL));
-		message->setDeleteChatPhoto(parse<bool>(obj, "delete_chat_photo", OPTIONAL));
-		message->setGroupChatCreated(parse<bool>(obj, "group_chat_created", OPTIONAL));
-		message->setSuperGroupChatCreated(parse<bool>(obj, "supergroup_chat_created", OPTIONAL));
-		message->setChannelChatCreated(parse<bool>(obj, "channel_chat_created", OPTIONAL));
-		message->setMigrateToChatId(parse<std::int64_t>(obj, "migrate_to_chat_id", OPTIONAL));
-		message->setMigrateFromChatId(parse<std::int64_t>(obj, "migrate_from_chat_id", OPTIONAL));
+		message->setAttachment(allow<Attachment>(obj, ""));
+		message->setCaption(allow<std::string>(obj, "caption"));
+		message->setNewChatMember(allow<User>(obj, "new_chat_member"));
+		message->setLeftChatMember(allow<User>(obj, "left_chat_member"));
+		message->setNewChatTitle(allow<std::string>(obj, "new_chat_title"));
+		message->setNewChatPhoto(allow<PhotoSizeArray>(obj, "new_chat_photo"));
+		message->setDeleteChatPhoto(check(obj, "delete_chat_photo"));
+		message->setGroupChatCreated(check(obj, "group_chat_created"));
+		message->setSuperGroupChatCreated(check(obj, "supergroup_chat_created"));
+		message->setChannelChatCreated(check(obj, "channel_chat_created"));
+		message->setMigrateToChatId(allow<std::int64_t>(obj, "migrate_to_chat_id"));
+		message->setMigrateFromChatId(allow<std::int64_t>(obj, "migrate_from_chat_id"));
 		message->setPinnedMessage(parseMessage(obj, "pinned_message", OPTIONAL));
-
-		return message;
 	}
-	else
-		return nullptr;
-}
-
-std::unique_ptr<Chat> parseChat(const rapidjson::Value& parent, const char* name, bool required)
-{
-	bool found;
-	auto& obj = parseObject(parent, name, required, found);
-	if (found)
-	{
-		auto chat = std::make_unique<Chat>();
-		chat->setId(parse<std::int64_t>(obj, "id", REQUIRED));
-		chat->setType(chatTypeFromString(parse<std::string>(obj, "type", REQUIRED)));
-		chat->setTitle(parse<std::string>(obj, "title", OPTIONAL));
-		chat->setUsername(parse<std::string>(obj, "username", OPTIONAL));
-		chat->setFirstName(parse<std::string>(obj, "first_name", OPTIONAL));
-		chat->setLastName(parse<std::string>(obj, "last_name", OPTIONAL));
-		chat->setAllAdmins(parse<bool>(obj, "all_members_are_administrators", OPTIONAL));
-		return chat;
-	}
-	else
-		return nullptr;
+	return message;
 }
 
 /// \todo Other updates
-std::unique_ptr<Update> parseUpdate(const rapidjson::Value& obj)
+Update parseUpdate(const rapidjson::Value& obj)
 {
-	int id = parse<int>(obj, "update_id", REQUIRED);
+	int id = require<int>(obj, "update_id");
 
 	std::unique_ptr<Message> message;
 	if ((message = parseMessage(obj, "message", OPTIONAL)))
-		return std::make_unique<MessageUpdate>(id, MessageUpdate::MessageType::Message, *message);
+		return Update(id, Update::Type::Message, std::move(message));
 	else if ((message = parseMessage(obj, "edited_message", OPTIONAL)))
-		return std::make_unique<MessageUpdate>(id, MessageUpdate::MessageType::EditedMessage, *message);
+		return Update(id, Update::Type::EditedMessage, std::move(message));
 	else if ((message = parseMessage(obj, "channel_post", OPTIONAL)))
-		return std::make_unique<MessageUpdate>(id, MessageUpdate::MessageType::ChannelPost, *message);
+		return Update(id, Update::Type::ChannelPost, std::move(message));
 	else if ((message = parseMessage(obj, "edited_channel_post", OPTIONAL)))
-		return std::make_unique<MessageUpdate>(id, MessageUpdate::MessageType::EditedChannelPost, *message);
+		return Update(id, Update::Type::EditedChannelPost, std::move(message));
 	else
-		///throw ParseError("Unknown update type");
-		return nullptr;
+		throw ParseError("Unknown update type");
 }
 
-std::unique_ptr<Updates> parseUpdates(const rapidjson::Value& parent, const char* name, bool required)
+Updates parseUpdates(const rapidjson::Value& parent, const char* name)
 {
+	Updates updates;
 	bool found;
-	auto& obj = parseArray(parent, name, required, found);
+	auto& obj = parseArray(parent, name, REQUIRED, found);
 	if (found)
 	{
-		Updates updates;
+		updates.reserve(obj.GetArray().Size());
 		for (auto& elem : obj.GetArray())
 			updates.emplace_back(parseUpdate(elem));
-		return std::make_unique<Updates>(std::move(updates));
 	}
-	else
-		return nullptr;
-}
-
-std::unique_ptr<User> parseUser(const rapidjson::Value& parent, const char* name, bool required)
-{
-	bool found;
-	auto& obj = parseObject(parent, name, required, found);
-	if (found)
-	{
-		auto user = std::make_unique<User>();
-		user->setId(parse<int>(obj, "id", REQUIRED));
-		user->setFirstName(parse<std::string>(obj, "first_name", REQUIRED));
-		user->setLastName(parse<std::string>(obj, "last_name", OPTIONAL));
-		user->setUsername(parse<std::string>(obj, "username", OPTIONAL));
-		return user;
-	}
-	else
-		return nullptr;
+	return updates;
 }
 
 void checkResponse(const rapidjson::Document& doc)
@@ -306,11 +286,11 @@ void checkResponse(const rapidjson::Document& doc)
 		throw ParseError("Object expected");
 
 	// Get status
-	bool ok = parse<bool>(doc, "ok", REQUIRED);
+	bool ok = require<bool>(doc, "ok");
 	if (!ok)
 	{
-		int code = parse<int>(doc, "error_code", REQUIRED);
-		std::string description(parse<std::string>(doc, "description", REQUIRED));
+		int code = require<int>(doc, "error_code");
+		std::string description(require<std::string>(doc, "description"));
 		throw ApiError(code, description);
 	}
 }
diff --git a/src/JsonObjects.hpp b/src/JsonObjects.hpp
index a315ac2..4bddd7e 100644
--- a/src/JsonObjects.hpp
+++ b/src/JsonObjects.hpp
@@ -5,6 +5,8 @@
 #include <telebotxx/Message.hpp>
 #include <telebotxx/Update.hpp>
 #include <telebotxx/User.hpp>
+#include <telebotxx/Optional.hpp>
+#include <telebotxx/Exception.hpp>
 
 #include <memory>
 
@@ -15,19 +17,58 @@ namespace telebotxx {
 const bool REQUIRED = true;
 const bool OPTIONAL = false;
 
-/// \brief Parse JSON object to Chat
-/// \param parent reference to parent JSON object
-/// \param name field with Chat object
-/// \param required REQUIRED or OPTIONAL
-/// \return pointer to Chat
-std::unique_ptr<Chat> parseChat(const rapidjson::Value& parent, const char* name, bool required);
+namespace impl {
+
+template<typename T> bool is(const rapidjson::Value& obj);
+template<> bool is<int>(const rapidjson::Value& obj);
+template<> bool is<std::int64_t>(const rapidjson::Value& obj);
+template<> bool is<bool>(const rapidjson::Value& obj);
+template<> bool is<std::string>(const rapidjson::Value& obj);
+
+template<typename T> const T get(const rapidjson::Value& obj);
+template<> const int get(const rapidjson::Value& obj);
+template<> const std::int64_t get(const rapidjson::Value& obj);
+template<> const bool get(const rapidjson::Value& obj);
+template<> const std::string get(const rapidjson::Value& obj);
+
+}
+
+template<typename T>
+optional<T> parse(const rapidjson::Value& obj, const char* name, bool required)
+{
+	if (obj.HasMember(name))
+	{
+		if (impl::is<T>(obj[name]))
+			return impl::get<T>(obj[name]);
+		else
+			throw ParseError(std::string("Field '") + name + "' has invalid type");
+	}
+	else if (required)
+		throw ParseError(std::string("Field '") + name + "' not found");
+	else
+		return boost::none;
+}
+
+template <typename T>
+T require(const rapidjson::Value& obj, const char* name)
+{
+	return *parse<T>(obj, name, REQUIRED);
+}
+
+template <typename T>
+optional<T> allow(const rapidjson::Value& obj, const char* name)
+{
+	return parse<T>(obj, name, OPTIONAL);
+}
+
+bool check(const rapidjson::Value& obj, const char* name);
 
 /// \brief Parse JSON object to User
 /// \param parent reference to parent JSON object
 /// \param name field with Document object
 /// \param required REQUIRED or OPTIONAL
 /// \return pointer to User
-std::unique_ptr<User> parseUser(const rapidjson::Value& parent, const char* name, bool required);
+template<> optional<User> parse<User>(const rapidjson::Value& parent, const char* name, bool required);
 
 /// \brief Parse JSON object to Message
 /// \param parent reference to parent JSON object
@@ -39,9 +80,8 @@ std::unique_ptr<Message> parseMessage(const rapidjson::Value& parent, const char
 /// \brief Parse JSON array of Update
 /// \param parent reference to parent JSON object
 /// \param name field with array of Update objects
-/// \param required REQUIRED or OPTIONAL
 /// \return Updates (vector of UpdatePtr>
-std::unique_ptr<Updates> parseUpdates(const rapidjson::Value& parent, const char* name, bool required);
+Updates parseUpdates(const rapidjson::Value& parent, const char* name);
 
 /// \brief Check JSON response
 ///
diff --git a/src/Message.cpp b/src/Message.cpp
index 011e693..b7288c2 100644
--- a/src/Message.cpp
+++ b/src/Message.cpp
@@ -9,12 +9,6 @@ MessageEntity::MessageEntity()
 {
 }
 
-MessageEntity::MessageEntity(const MessageEntity&) = default;
-
-MessageEntity::MessageEntity(MessageEntity&&) = default;
-
-MessageEntity::~MessageEntity() = default;
-
 MessageEntity::Type MessageEntity::getType() const
 {
 	return type_;
@@ -45,40 +39,24 @@ void MessageEntity::setLength(size_t length)
 	length_ = length;
 }
 
-const std::string& MessageEntity::getUrl() const
+const optional<std::string>& MessageEntity::getUrl() const
 {
 	return url_;
 }
 
-void MessageEntity::setUrl(const std::string& url)
+void MessageEntity::setUrl(std::string url)
 {
-	url_ = url;
+	url_ = std::move(url);
 }
 
-const User& MessageEntity::getUser() const
+const optional<User>& MessageEntity::getUser() const
 {
 	return user_;
 }
 
-void MessageEntity::setUser(const User& user)
+void MessageEntity::setUser(User user)
 {
-	user_ = user;
-}
-
-void MessageEntity::swap(MessageEntity& other) noexcept
-{
-	using std::swap;
-	swap(type_, other.type_);
-	swap(offset_, other.offset_);
-	swap(length_, other.length_);
-	swap(url_, other.url_);
-	swap(user_, other.user_);
-}
-
-const MessageEntity& MessageEntity::operator=(MessageEntity other)
-{
-	swap(other);
-	return *this;
+	user_ = std::move(user);
 }
 
 MessageEntity::Type messageEntityTypeFromString(const std::string& str)
@@ -109,17 +87,17 @@ MessageEntity::Type messageEntityTypeFromString(const std::string& str)
 		throw std::invalid_argument("Unknown message entity type");
 }
 
+////////////////////////////////////////////////////////////////
+
 Message::Message()
-	: id_(-1)
+	: id_(-1),
+	  deleteChatPhoto_(false),
+	  groupChatCreated_(false),
+	  superGroupChatCreated_(false),
+	  channelChatCreated_(false)
 {
 }
 
-Message::Message(const Message&) = default;
-
-Message::Message(Message&&) = default;
-
-Message::~Message() = default;
-
 int Message::getId() const
 {
 	return id_;
@@ -130,14 +108,14 @@ void Message::setId(int id)
 	id_ = id;
 }
 
-const UserPtr Message::getFrom() const
+const boost::optional<User>& Message::getFrom() const
 {
 	return from_;
 }
 
-void Message::setFrom(UserPtr from)
+void Message::setFrom(optional<User> from)
 {
-	from_ = from;
+	from_ = std::move(from);
 }
 
 time_t Message::getDate() const
@@ -155,42 +133,42 @@ const Chat& Message::getChat() const
 	return chat_;
 }
 
-void Message::setChat(const Chat& chat)
+void Message::setChat(Chat chat)
 {
-	chat_ = chat;
+	chat_ = std::move(chat);
 }
 
-const UserPtr Message::getForwardFrom() const
+const optional<User>& Message::getForwardFrom() const
 {
 	return forwardFrom_;
 }
 
-void Message::setForwardFrom(UserPtr forwardFrom)
+void Message::setForwardFrom(optional<User> forwardFrom)
 {
-	forwardFrom_ = forwardFrom;
+	forwardFrom_ = std::move(forwardFrom);
 }
 
-const ChatPtr Message::getForwardFromChat() const
+const optional<Chat>& Message::getForwardFromChat() const
 {
 	return forwardFromChat_;
 }
 
-void Message::setForwardFromChat(ChatPtr forwardFromChat)
+void Message::setForwardFromChat(optional<Chat> forwardFromChat)
 {
-	forwardFromChat_ = forwardFromChat;
+	forwardFromChat_ = std::move(forwardFromChat);
 }
 
-time_t Message::getForwardDate() const
+const optional<time_t>& Message::getForwardDate() const
 {
 	return forwardDate_;
 }
 
-void Message::setForwardDate(time_t forwardDate)
+void Message::setForwardDate(optional<time_t> forwardDate)
 {
 	forwardDate_ = forwardDate;
 }
 
-const MessagePtr Message::getReplyToMessage() const
+MessagePtr Message::getReplyToMessage() const
 {
 	return replyToMessage_;
 }
@@ -200,94 +178,94 @@ void Message::setReplyToMessage(MessagePtr replyToMessage)
 	replyToMessage_ = replyToMessage;
 }
 
-time_t Message::getEditDate() const
+const optional<time_t>& Message::getEditDate() const
 {
 	return editDate_;
 }
 
-void Message::setEditDate(time_t editDate)
+void Message::setEditDate(optional<time_t> editDate)
 {
 	editDate_ = editDate;
 }
 
-const std::string& Message::getText() const
+const optional<std::string>& Message::getText() const
 {
 	return text_;
 }
 
-void Message::setText(const std::string& text)
+void Message::setText(optional<std::string> text)
 {
-	text_ = text;
+	text_ = std::move(text);
 }
 
-const MessageEntities& Message::getEntities() const
+const optional<MessageEntities>& Message::getEntities() const
 {
 	return entities_;
 }
 
-void Message::setEntities(MessageEntities&& entities)
+void Message::setEntities(optional<MessageEntities> entities)
 {
-	entities_ = entities;
+	entities_ = std::move(entities);
 }
 
-const AttachmentPtr Message::getAttachment() const
+const optional<Attachment>& Message::getAttachment() const
 {
 	return attachment_;
 }
 
-void Message::setAttachment(AttachmentPtr attachment)
+void Message::setAttachment(optional<Attachment> attachment)
 {
-	attachment_ = attachment;
+	attachment_ = std::move(attachment);
 }
 
-const std::string& Message::getCaption() const
+const optional<std::string>& Message::getCaption() const
 {
 	return caption_;
 }
 
-void Message::setCaption(const std::string& caption)
+void Message::setCaption(optional<std::string> caption)
 {
-	caption_ = caption;
+	caption_ = std::move(caption);
 }
 
-const UserPtr Message::getNewChatMember() const
+const optional<User>& Message::getNewChatMember() const
 {
 	return newChatMember_;
 }
 
-void Message::setNewChatMember(UserPtr newChatMember)
+void Message::setNewChatMember(optional<User> newChatMember)
 {
-	newChatMember_ = newChatMember;
+	newChatMember_ = std::move(newChatMember);
 }
 
-const UserPtr Message::getLeftChatMember() const
+const optional<User>& Message::getLeftChatMember() const
 {
 	return leftChatMember_;
 }
 
-void Message::setLeftChatMember(UserPtr leftChatMember)
+void Message::setLeftChatMember(optional<User> leftChatMember)
 {
-	leftChatMember_ = leftChatMember;
+	leftChatMember_ = std::move(leftChatMember);
 }
 
-const std::string& Message::getNewChatTitle() const
+const optional<std::string>& Message::getNewChatTitle() const
 {
 	return newChatTitle_;
 }
 
-void Message::setNewChatTitle(const std::string& newChatTitle)
+void Message::setNewChatTitle(optional<std::string> newChatTitle)
 {
-	newChatTitle_ = newChatTitle;
+	newChatTitle_ = std::move(newChatTitle);
 }
 
-const PhotoSizeArrayPtr Message::getNewChatPhoto() const
+const optional<PhotoSizeArray> Message::getNewChatPhoto() const
 {
 	return newChatPhoto_;
 }
 
-void Message::setNewChatPhoto(PhotoSizeArrayPtr newChatPhoto)
+void Message::setNewChatPhoto(optional<PhotoSizeArray> newChatPhoto)
 {
-	newChatPhoto_ = newChatPhoto;
+	newChatPhoto_ = std::move(newChatPhoto);
 }
 
 bool Message::isDeleteChatPhoto() const
@@ -330,27 +308,27 @@ void Message::setChannelChatCreated(bool channelChatCreated)
 	channelChatCreated_ = channelChatCreated;
 }
 
-std::int64_t Message::getMigrateToChatId() const
+const optional<std::int64_t>& Message::getMigrateToChatId() const
 {
 	return migrateToChatId_;
 }
 
-void Message::setMigrateToChatId(std::int64_t migrateToChatId)
+void Message::setMigrateToChatId(optional<std::int64_t> migrateToChatId)
 {
 	migrateToChatId_ = migrateToChatId;
 }
 
-std::int64_t Message::getMigrateFromChatId() const
+const optional<std::int64_t>& Message::getMigrateFromChatId() const
 {
 	return migrateFromChatId_;
 }
 
-void Message::setMigrateFromChatId(std::int64_t migrateFromChatId)
+void Message::setMigrateFromChatId(optional<std::int64_t> migrateFromChatId)
 {
 	migrateFromChatId_ = migrateFromChatId;
 }
 
-const MessagePtr Message::getPinnedMessage() const
+MessagePtr Message::getPinnedMessage() const
 {
 	return pinnedMessage_;
 }
@@ -360,44 +338,4 @@ void Message::setPinnedMessage(MessagePtr pinnedMessage)
 	pinnedMessage_ = pinnedMessage;
 }
 
-void Message::swap(Message& other) noexcept
-{
-	using std::swap;
-	swap(id_, other.id_);
-	swap(from_, other.from_);
-	swap(date_, other.date_);
-	swap(chat_, other.chat_);
-	swap(forwardFrom_, other.forwardFrom_);
-	swap(forwardFromChat_, other.forwardFromChat_);
-	swap(forwardDate_, other.forwardDate_);
-	swap(replyToMessage_, other.replyToMessage_);
-	swap(editDate_, other.editDate_);
-	swap(text_, other.text_);
-	swap(entities_, other.entities_);
-	swap(attachment_, other.attachment_);
-	swap(caption_, other.caption_);
-	swap(newChatMember_, other.newChatMember_);
-	swap(leftChatMember_, other.leftChatMember_);
-	swap(newChatTitle_, other.newChatTitle_);
-	swap(newChatPhoto_, other.newChatPhoto_);
-	swap(deleteChatPhoto_, other.deleteChatPhoto_);
-	swap(groupChatCreated_, other.groupChatCreated_);
-	swap(superGroupChatCreated_, other.superGroupChatCreated_);
-	swap(channelChatCreated_, other.channelChatCreated_);
-	swap(migrateToChatId_, other.migrateToChatId_);
-	swap(migrateFromChatId_, other.migrateFromChatId_);
-	swap(pinnedMessage_, other.pinnedMessage_);
-}
-
-const Message& Message::operator=(Message other) noexcept
-{
-	swap(other);
-	return *this;
-}
-
-void swap(Message& lhs, Message& rhs)
-{
-	lhs.swap(rhs);
-}
-
 }
diff --git a/src/RequestOptions.cpp b/src/RequestOptions.cpp
index 54f80ae..5323c2b 100644
--- a/src/RequestOptions.cpp
+++ b/src/RequestOptions.cpp
@@ -20,10 +20,6 @@ ChatId::ChatId(const std::string& str)
 {
 }
 
-ChatId::ChatId(const ChatId& other) = default;
-ChatId::ChatId(ChatId&& other) = default;
-ChatId::~ChatId() = default;
-
 ChatId::Type ChatId::getType() const
 {
 	return type_;
@@ -124,10 +120,6 @@ Photo::Photo(const Url& url)
 {
 }
 
-Photo::Photo(const Photo& other) = default;
-Photo::Photo(Photo&& other) = default;
-Photo::~Photo() = default;
-
 Photo::Type Photo::getType() const
 {
 	return type_;
diff --git a/src/Update.cpp b/src/Update.cpp
index 303192e..d9affee 100644
--- a/src/Update.cpp
+++ b/src/Update.cpp
@@ -1,66 +1,28 @@
 #include <telebotxx/Update.hpp>
+#include <boost/variant.hpp>
 
 namespace telebotxx {
 
-Update::Update(int id, Type type)
+Update::Update(int id, Type type, std::unique_ptr<Message> message)
 	: id_(id),
-	  updateType_(type)
+	  type_(type),
+	  value_(std::move(message))
 {
 }
 
-Update::Update(const Update&) = default;
-Update::Update(Update&&) = default;
-Update::~Update() = default;
-
 int Update::getId() const
 {
 	return id_;
 }
 
 Update::Type Update::getType() const
-{
-	return updateType_;
-}
-
-void Update::swap(Update& other) noexcept
-{
-	using std::swap;
-	swap(id_, other.id_);
-	swap(updateType_, other.updateType_);
-}
-
-////////////////////////////////////////////////////////////////
-
-MessageUpdate::MessageUpdate(int id, MessageType type, const Message& message)
-	: Update(id, Type::Message), type_(type), message_(message)
-{
-}
-
-MessageUpdate::MessageUpdate(const MessageUpdate&) = default;
-MessageUpdate::MessageUpdate(MessageUpdate&&) = default;
-MessageUpdate::~MessageUpdate() = default;
-
-MessageUpdate::MessageType MessageUpdate::getMessageType() const
 {
 	return type_;
 }
 
-const Message& MessageUpdate::getMessage() const
+MessagePtr Update::getMessage() const
 {
-	return message_;
-}
-
-void MessageUpdate::swap(MessageUpdate& other) noexcept
-{
-	using std::swap;
-	Update::swap(other);
-	swap(message_, other.message_);
-}
-
-const MessageUpdate& MessageUpdate::operator=(MessageUpdate other)
-{
-	swap(other);
-	return *this;
+	return boost::get<MessagePtr>(value_);
 }
 
 }
diff --git a/src/User.cpp b/src/User.cpp
index 1de2a54..c17813e 100644
--- a/src/User.cpp
+++ b/src/User.cpp
@@ -8,12 +8,6 @@ User::User()
 {
 }
 
-User::User(const User&) = default;
-
-User::User(User&&) = default;
-
-User::~User() = default;
-
 int User::getId() const
 {
 	return id_;
@@ -29,52 +23,42 @@ const std::string& User::getFirstName() const
 	return firstName_;
 }
 
-void User::setFirstName(const std::string& firstName)
+void User::setFirstName(std::string firstName)
 {
-	firstName_ = firstName;
+	firstName_ = std::move(firstName);
 }
 
-const std::string& User::getLastName() const
+const optional<std::string>& User::getLastName() const
 {
 	return lastName_;
 }
 
-void User::setLastName(const std::string& lastName)
+void User::setLastName(optional<std::string> lastName)
 {
-	lastName_ = lastName;
+	lastName_ = std::move(lastName);
 }
 
-const std::string& User::getUsername() const
+const optional<std::string>& User::getUsername() const
 {
 	return username_;
 }
 
-void User::setUsername(const std::string& username)
+void User::setUsername(optional<std::string> username)
 {
-	username_ = username;
+	username_ = std::move(username);
 }
 
 const std::string User::toString() const
 {
 	std::stringstream ss;
-	ss << firstName_ << " " << lastName_ << " (@" << username_ << ")";
+	ss << firstName_;
+	if (lastName_)
+		ss << " " << *lastName_;
+	if (username_)
+		ss << " (@" << *username_ << ")";
 	return ss.str();
 }
 
-void User::swap(User& other) noexcept
-{
-	std::swap(id_, other.id_);
-	firstName_.swap(other.firstName_);
-	lastName_.swap(other.lastName_);
-	username_.swap(other.username_);
-}
-
-const User& User::operator=(User other)
-{
-	swap(other);
-	return *this;
-}
-
 std::ostream& operator<<(std::ostream& os, const User& user)
 {
 	os << user.toString();
diff --git a/tests/TestApi.cpp b/tests/TestApi.cpp
index ef9a67f..a398fc4 100644
--- a/tests/TestApi.cpp
+++ b/tests/TestApi.cpp
@@ -86,7 +86,7 @@ struct TestConfig
 
 BOOST_GLOBAL_FIXTURE(TestConfig);
 
-BOOST_AUTO_TEST_SUITE(TestBotApi)
+BOOST_AUTO_TEST_SUITE(TestSend)
 
 	BOOST_AUTO_TEST_CASE(DefaultConstructor)
 	{
@@ -198,6 +198,10 @@ BOOST_AUTO_TEST_SUITE(TestBotApi)
 		));
 	}
 
+BOOST_AUTO_TEST_SUITE_END()
+
+BOOST_AUTO_TEST_SUITE(TestParse)
+
 	BOOST_AUTO_TEST_CASE(GetUpdates)
 	{
 		PRINT_TESTNAME;
@@ -206,19 +210,22 @@ BOOST_AUTO_TEST_SUITE(TestBotApi)
 		BOOST_REQUIRE_NO_THROW(updates = bot->getUpdates());
 		for (auto update : updates)
 		{
-			switch (update->getType())
+			switch (update.getType())
 			{
 				case Update::Type::Message:
+				case Update::Type::EditedMessage:
+				case Update::Type::ChannelPost:
+				case Update::Type::EditedChannelPost:
 				{
-					auto& message = std::dynamic_pointer_cast<MessageUpdate>(update)->getMessage();
-					if (message.getFrom())
-						std::cout << *message.getFrom() << ": ";
-					std::cout << message.getText() << std::endl;
+					auto message = update.getMessage();
+					if (message->getFrom())
+						std::cout << *message->getFrom() << ": ";
+					if (message->getText())
+						std::cout << *message->getText() << std::endl;
 					break;
 				}
 			}
 		}
 	}
 
-
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/tests/TestTypes.cpp b/tests/TestTypes.cpp
index 2574734..0bc5e57 100644
--- a/tests/TestTypes.cpp
+++ b/tests/TestTypes.cpp
@@ -17,15 +17,15 @@ BOOST_AUTO_TEST_SUITE(TestUser)
 		PRINT_TESTNAME;
 		User other;
 		other.setId(1);
-		other.setFirstName("John");
-		other.setLastName("Smith");
-		other.setUsername("john_smith");
+		other.setFirstName(std::string("John"));
+		other.setLastName(std::string("Smith"));
+		other.setUsername(std::string("john_smith"));
 		std::unique_ptr<User> user;
 		BOOST_REQUIRE_NO_THROW(user.reset(new User(other)));
 		BOOST_REQUIRE_EQUAL(user->getId(), 1);
 		BOOST_REQUIRE_EQUAL(user->getFirstName(), "John");
-		BOOST_REQUIRE_EQUAL(user->getLastName(), "Smith");
-		BOOST_REQUIRE_EQUAL(user->getUsername(), "john_smith");
+		BOOST_REQUIRE_EQUAL(*user->getLastName(), "Smith");
+		BOOST_REQUIRE_EQUAL(*user->getUsername(), "john_smith");
 	}
 
 	BOOST_AUTO_TEST_CASE(MoveConstructor)
@@ -33,15 +33,15 @@ BOOST_AUTO_TEST_SUITE(TestUser)
 		PRINT_TESTNAME;
 		User other;
 		other.setId(1);
-		other.setFirstName("John");
-		other.setLastName("Smith");
-		other.setUsername("john_smith");
+		other.setFirstName(std::string("John"));
+		other.setLastName(std::string("Smith"));
+		other.setUsername(std::string("john_smith"));
 		std::unique_ptr<User> user;
 		BOOST_REQUIRE_NO_THROW(user.reset(new User(std::move(other))));
 		BOOST_REQUIRE_EQUAL(user->getId(), 1);
 		BOOST_REQUIRE_EQUAL(user->getFirstName(), "John");
-		BOOST_REQUIRE_EQUAL(user->getLastName(), "Smith");
-		BOOST_REQUIRE_EQUAL(user->getUsername(), "john_smith");
+		BOOST_REQUIRE_EQUAL(*user->getLastName(), "Smith");
+		BOOST_REQUIRE_EQUAL(*user->getUsername(), "john_smith");
 	}
 
 BOOST_AUTO_TEST_SUITE_END()