operator makes coding much simpler and clearer when accessing elements in random_acess_ranges like vector and deque. It is also useful for the bidirectional_ranges like map and unordered_map. We could like to use operator in the graph
algorithms and doing so would support writing more generic code, but the concepts for those ranges don’t require operator.
Is there a reason operator isn’t a requirement for random_access_range? For bidirectional_range?
We would create a concept that would require operator. What caveats are there in doing that?