diff --git a/membuffer/membuffer.h b/membuffer/membuffer.h
index 6accc92..5e9850a 100644
--- a/membuffer/membuffer.h
+++ b/membuffer/membuffer.h
@@ -115,7 +115,7 @@ public:
 	MemBuffer & operator=(const MemBuffer<item_type, stack_size, heap_block_size> & arg);
 
 	void append(item_type item);
-	void append(item_type * item_array, size_t len);
+	void append(const item_type * item_array, size_t len);
 	
 	template<typename arg_item_type, size_t arg_stack_size, size_t arg_heap_block_size>
 	void append(const MemBuffer<arg_item_type, arg_stack_size, arg_heap_block_size> & arg);
@@ -553,7 +553,7 @@ void MemBuffer<item_type, stack_size, heap_block_size>::append(item_type item)
 
 
 template<typename item_type, size_t stack_size, size_t heap_block_size>
-void MemBuffer<item_type, stack_size, heap_block_size>::append(item_type * item_array, size_t len)
+void MemBuffer<item_type, stack_size, heap_block_size>::append(const item_type * item_array, size_t len)
 {
 	if( size_used + len <= stack_size )
 	{
diff --git a/textstream/textstream.h b/textstream/textstream.h
index ec7db84..3f93a5e 100644
--- a/textstream/textstream.h
+++ b/textstream/textstream.h
@@ -105,16 +105,26 @@ public:
 	TextStreamBase & operator<<(const PT::Space & space);
 	TextStreamBase & operator<<(const PT::Date & date);
 
+	template<typename arg_char_type, size_t arg_stack_size, size_t arg_heap_block_size>
+	TextStreamBase & operator<<(const TextStreamBase<arg_char_type, arg_stack_size, arg_heap_block_size> & arg);
+
 	TextStreamBase & write(const char * buf,    size_t len);
 	TextStreamBase & write(const wchar_t * buf, size_t len);
 
-protected:
 
+	/*
+		 raw access
+	*/
 	int radix;
 	buffer_type buffer;
 };
 
 
+typedef TextStreamBase<char,    256, 4096> TextStream;
+typedef TextStreamBase<wchar_t, 256, 4096> WTextStream;
+
+
+
 
 template<typename char_type, size_t stack_size, size_t heap_block_size>
 TextStreamBase<char_type, stack_size, heap_block_size>::TextStreamBase()
@@ -430,6 +440,20 @@ return *this;
 }
 
 
+
+template<typename char_type, size_t stack_size, size_t heap_block_size>
+template<typename arg_char_type, size_t arg_stack_size, size_t arg_heap_block_size>
+TextStreamBase<char_type, stack_size, heap_block_size> &
+TextStreamBase<char_type, stack_size, heap_block_size>::operator<<(
+		const TextStreamBase<arg_char_type, arg_stack_size, arg_heap_block_size> & arg)
+{
+	buffer.append(arg.buffer);
+
+return *this;
+}
+
+
+
 } // namespace