example we passed an argument by reference and we were not planning to
change it. We passed it only for convenience and speed. If you are not
planning to modify the value it is safer to use
keyword. You can rewrite the function like this:
Point GetReflectedCopy (
const Point &From )
keyword does not change the behavior of
but does make it safer – remember there are risks associated with pass
by reference. If by accident you try to change its value, the compiler
will complain and will not allow you to do this.
It is much easier to catch the problem when compiler complains rather
to change its argument by mistake and then debug the problem later.