Fix#36.
Slicing for the SList on top of the existing SRange would be inefficent.
There would be two cases:
- Range iterates till the end of the list.
- Range iterates till some element "end".
If both cases are implemented in the same range, this range should check
for both conditions (end of the list and "begin == end") instead of only
one (end of the list).
Introducing a different range is undesirable since all containers have
currently only one range.