The example is correct. toIndex is exclusive. Here is Dijkstra's opinion on why: https://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html https:

The example is correct. toIndex is exclusive. Here is Dijkstra's opinion on why: https://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/EWD831.html https://www.cs.utexas.edu/users/EWD/transcriptions/EWD08xx/E...