PIMPL: adapt to new syntax

Change-Id: I10f304bdef1019b48f6fac3ea34ebc655005a2e7
Reviewed-on: http://gerrit.aldebaran.lan/49278
Reviewed-by: pdaouadi <pdaouadi@aldebaran-robotics.com>
Tested-by: pdaouadi <pdaouadi@aldebaran-robotics.com>