A subsequence represents an aliased reference to some part of an existing sequence.
Because subsequences are aliased references into other sequences, several properties must be remembered:
If the source sequences are instances of <vector> or <string>, then the implementation will use subclasses of <subsequence> which are also subclasses of <vector> or <string>.
abstract free sealed
| source: | An instance of <sequence>. Required. |
| start: | An instance of <integer>. Required. |
| end: | An instance of <integer>. Required. |