according to Krista, neither the bool parameter of mime_encode_message() nor the bool* of mime_decode_message are part of the API for the cloents. So I don't expose them to the JSON-RPC clients.

server/ev_server.cc

@@ -91,8 +91,8 @@ const FunctionMap functions = {
 		
 		// from mime.h
 		FP( "MIME handling API", new Separator),
-		FP( "mime_encode_message", new Func<PEP_STATUS, In<const message*>, In<bool>, Out<char*>, In<bool>>( &mime_encode_message )),
-		FP( "mime_decode_message", new Func<PEP_STATUS, In<c_string>, InLength<>, Out<message*>, Out<bool>>( &mime_decode_message )),
+		FP( "mime_encode_message", new Func<PEP_STATUS, In<const message*>, In<bool>, Out<char*>, In<bool, ParamFlag::NoInput>>( &mime_encode_message )),
+		FP( "mime_decode_message", new Func<PEP_STATUS, In<c_string>, InLength<>, Out<message*>, In<bool*, ParamFlag::NoInput>>( &mime_decode_message )),
 		
 		// from pEpEngine.h
 		FP( "pEp Engine Core API", new Separator),

server/inout.hh

@@ -82,6 +82,36 @@ struct In
 };
 
 
+template<class T>
+struct In<T, ParamFlag::NoInput>
+{
+	typedef T c_type; // the according type in C function parameter
+	enum { is_output = false, need_input = false };
+	typedef In<T, ParamFlag::NoInput> Self;
+	
+	explicit In(const T& t) : value(T{}) {}
+	~In() {}
+	
+	In(const Self& other) = delete;
+	In(Self&& victim) = delete;
+	Self& operator=(const Self&) = delete;
+	
+	// default implementation:
+	In(const js::Value& v, Context*, unsigned param_nr)
+	: value{ T{} }
+	{ }
+	
+	js::Value to_json() const
+	{
+		throw std::logic_error( std::string("Never call to_json() for a In<") + typeid(T).name() + "> data type!  fn=" + __PRETTY_FUNCTION__ );
+	}
+	
+	T get_value() const { return value; }
+	
+	T value;
+};
+
+
 // to call functions that operate directly on the JSON data type
 template<class T, ParamFlag PF=ParamFlag::Default>
 struct InRaw