9 Iterators library [iterators]

9.7 Iterator adaptors [iterators.predef]

9.7.6 Counted iterators [iterators.counted]

9.7.6.2 counted_iterator operations [counted.iter.ops]

9.7.6.2.12 counted_iterator::operator[] [counted.iter.op.index]

constexpr decltype(auto) operator[](difference_type n) const requires RandomAccessIterator<I>;

1

Requires: n <= cnt

2

Effects: Equivalent to: return current[n];