It is based on https://developer.mbed.org/users/gregeric/code/Nucleo_Hello_Encoder/

Revision:
4:d07f58c46a79
Parent:
3:65021ea3fae5
--- a/rotary_encoder_base/rotary_encoder_base.hpp	Thu Mar 31 04:42:31 2016 +0000
+++ b/rotary_encoder_base/rotary_encoder_base.hpp	Sun Apr 03 06:30:19 2016 +0000
@@ -1,6 +1,7 @@
 #ifndef INCLUDED_MBED_STL_ROTARY_ENCODER_BASE_H
 #define INCLUDED_MBED_STL_ROTARY_ENCODER_BASE_H
 
+#include "mbed.h"
 #include "rotary_encoder.hpp"
 
 namespace mbed_stl {