27 Iterators library [iterators]

27.5 Iterator adaptors [predef.iterators]

27.5.3 Move iterators [move.iterators]

27.5.3.3 move_­iterator operations [move.iter.ops]

27.5.3.3.12 move_­iterator​::​operator[] [move.iter.op.index]

constexpr unspecified operator[](difference_type n) const;