dropBackTo abstract method
Drops the last occurrence of target
in the range.
If the range contains any occurrences of target
,
then all characters after the start of the first such occurrence
is removed from the range.
This retracts the end of the range to the start of the
last occurrence of target
.
If there are no occurrences of target
in the range,
the range is not changed.
Returns true
if there is an occurrence of target
and false
if not.
Implementation
bool dropBackTo(Characters target);