Don't access objects after they have been std::move (#1536)
Don't access objects after they have been std::move (#1536)

According to the documentation at
https://en.cppreference.com/w/cpp/utility/move,
the "moved-from" objects are "in a valid but unspecified
state" after the move.  Thus, we shouldn't assume anything
about them, since it could be implementation-defined behavior.

Signed-off-by: Chris Lalancette <281cd07d7578d97c83271fbbf2faddb83ab3791c@openrobotics.org>
ros2/rclcpp,ros2/rclcpp