.. ot-topic:: cxx.exercises.fh_sensor_first_try.exercise_FH_sensor_oo_no_polymorphism
   :dependencies: cxx.exercises.fh_sensor_first_try.exercise_FH_sensor_oo_loop_function

.. include:: <mmlalias.txt>


Exercise (FH): Replace Sensor
=============================

.. contents::
   :local:

Requirement
-----------

As a followup to :doc:`exercise-FH-sensor-oo`, let's say we want to
replace ``W1Sensor`` with an instance of ``ConstantSensor`` (from
``<constant-sensor.h>``).

#. Make the change: replace every mention of ``W1Sensor`` with its
   ``ConstantSensor`` counterpart.
#. What do you notice? Respectively, which part of the program did you
   *not* expect to change?