Merge pull request #80 from cyanray/dev/cyanray

提升 MessageChain 的易用性.

Author: cyanray

include/mirai/defs/message_chain.hpp

@@ -34,16 +34,33 @@ namespace Cyan
 		typedef vector<std::shared_ptr<IMessage>>::iterator iterator;
 
 		friend MessageChain& operator+(const string& str, MessageChain& mc);
-		template<int N>
-		friend MessageChain& operator+(const char(&str)[N], MessageChain&& mc);
+
+		template<typename T>
+		friend MessageChain& operator+(T&& val, MessageChain& mc);
+
+		template<std::size_t N>
+		friend MessageChain& operator+(const char(&str)[N], MessageChain& mc);
+
 		MessageChain();
 		MessageChain(const MessageChain& mc);
 		MessageChain(MessageChain&& mc) noexcept;
 		MessageChain& operator=(const MessageChain& mc);
 		MessageChain& operator=(MessageChain&& mc) noexcept;
 		MessageChain& operator+(const MessageChain& mc);
 		MessageChain& operator+(const string& val);
-		MessageChain& operator+=(const string& val);
+
+		template<typename T>
+		MessageChain& operator+=(T&& val)
+		{
+			return this->Add(std::forward<T>(val));
+		}
+
+		template<std::size_t N>
+		MessageChain& operator+=(const char (&val)[N])
+		{
+			return this->Add<PlainMessage>(val);
+		}
+
 		bool operator==(const MessageChain& mc) const;
 		bool operator!=(const MessageChain& mc) const;
 		std::shared_ptr<IMessage> operator[](int i);
@@ -117,6 +134,11 @@ namespace Cyan
 			return messages_.size();
 		}
 
+		bool Empty() const
+		{
+			return Count() == 0;
+		}
+
 		void Clear()
 		{
 			messages_.clear();
@@ -218,8 +240,18 @@ namespace Cyan
 		vector<std::shared_ptr<IMessage>> messages_;
 	};
 
-	template<int N>
-	inline MessageChain& operator+(const char(&str)[N], MessageChain&& mc)
+	template<typename T>
+	inline MessageChain& operator+(T&& val, MessageChain& mc)
+	{
+		using real_type = typename std::remove_const<typename std::remove_reference<T>::type >::type;
+		static_assert(std::is_base_of<IMessage, real_type>::value, "只能接受 IMessage 的派生类");
+		std::shared_ptr<IMessage> m_ptr(new real_type(std::forward<T>(val)));
+		mc.messages_.insert(mc.messages_.begin(), m_ptr);
+		return mc;
+	}
+
+	template<std::size_t N>
+	inline MessageChain& operator+(const char(&str)[N], MessageChain& mc)
 	{
 		mc.messages_.insert(mc.messages_.begin(), std::make_shared<PlainMessage>(str));
 		return mc;
@@ -230,7 +262,6 @@ namespace Cyan
 		mc.messages_.insert(mc.messages_.begin(), std::make_shared<PlainMessage>(str));
 		return mc;
 	}
-
 }
 
 

src/message_chain.cpp

@@ -66,11 +66,6 @@ namespace Cyan
 		return this->Plain(val);
 	}
 
-	MessageChain& MessageChain::operator+=(const string& val)
-	{
-		return this->Plain(val);
-	}
-
 	bool MessageChain::operator==(const MessageChain& mc) const
 	{
 		if (this->messages_.size() != mc.messages_.size()) return false;