@@ -92,41 +92,41 @@ void Stringifier::formatString(const std::string& value, std::ostream& out)
 	out << '"';
 	for (std::string::const_iterator it = value.begin(); it != value.end(); ++it)
 	{
-		switch (*it)
-		{
-		case '"':
+		if (*it == 0x20 ||
+			*it == 0x21 ||
+			(*it >= 0x23 && *it <= 0x2E) ||
+			(*it >= 0x30 && *it <= 0x5B) ||
+			(*it >= 0x5D && *it <= 0xFF))
+			out << *it;
+		else if (*it == '"')
 			out << "\\\"";
-			break;
-		case '\\':
+		else if (*it == '\\')
 			out << "\\\\";
-			break;
-		case '\b':
+		else if (*it == '\b')
 			out << "\\b";
-			break;
-		case '\f':
+		else if (*it == '\f')
 			out << "\\f";
-			break;
-		case '\n':
+		else if (*it == '\n')
 			out << "\\n";
-			break;
-		case '\r':
+		else if (*it == '\r')
 			out << "\\r";
-			break;
-		case '\t':
+		else if (*it == '\t')
 			out << "\\t";
-			break;
-		default:
+		else if ( *it == '\0' )
+			out << "\\u0000";
+		else
 		{
-			if ( *it > 0 && *it <= 0x1F )
-			{
-				out << "\\u" << std::hex << std::uppercase << std::setfill('0') << std::setw(4) << static_cast<int>(*it);
-			}
-			else
-			{
-				out << *it;
-			}
-			break;
-		}
+			const char *hexdigits = "0123456789ABCDEF";
+			unsigned long u = (std::min)(static_cast<unsigned long>(static_cast<unsigned char>(*it)), 0xFFFFul);
+			int d1 = u / 4096; u -= d1 * 4096;
+			int d2 = u / 256; u -= d2 * 256;
+			int d3 = u / 16; u -= d3 * 16;
+			int d4 = u;
+			out << "\\u";
+			out << hexdigits[d1];
+			out << hexdigits[d2];
+			out << hexdigits[d3];
+			out << hexdigits[d4];
 		}
 	}
 	out << '"';
 
@@ -76,7 +76,7 @@ class MongoDB_API MessageHeader
 	void write(BinaryWriter& writer);
 		/// Writes the header
 
-	std::size_t getMessageLength() const;
+	Int32 getMessageLength() const;
 		/// Returns the message length
 
 	OpCode opCode() const;
@@ -95,13 +95,13 @@ class MongoDB_API MessageHeader
 	MessageHeader(OpCode opcode);
 		/// Constructor.
 
-	void setMessageLength(std::size_t length);
+	void setMessageLength(Int32 length);
 		/// Sets the message length
 
-	std::size_t _messageLength;
-	Int32       _requestID;
-	Int32       _responseTo;
-	OpCode      _opCode;
+	Int32 _messageLength;
+	Int32 _requestID;
+	Int32 _responseTo;
+	OpCode _opCode;
 
 	friend class Message;
 };
@@ -113,13 +113,13 @@ inline MessageHeader::OpCode MessageHeader::opCode() const
 }
 
 
-inline std::size_t MessageHeader::getMessageLength() const
+inline Int32 MessageHeader::getMessageLength() const
 {
 	return _messageLength;
 }
 
 
-inline void MessageHeader::setMessageLength(std::size_t length)
+inline void MessageHeader::setMessageLength(Int32 length)
 {
 	_messageLength = MSG_HEADER_SIZE + length;
 }