@dxw00d Yeah I saw that code in main.cpp What i wanted to say was there doesnt seems to be any implementation of bufferUntil in the codebase.
I downloaded the current development version of hardwareSerial.cpp https://github.com/arduino/Arduino/blob/master/hardware/arduino/cores/arduino/HardwareSerial.cpp and there still doesnt seems to be an implementation for bufferUntil in it eighter.
I would have liked it if there was an existing code for that function. I would hate to reinvent the wheel.
Someone should make a note in the docs that buffer and bufferUntil are currently not implemented.