25 Iterators library [iterators]

25.5 Iterator adaptors [predef.iterators]

25.5.5 Common iterators [iterators.common]

25.5.5.7 Customizations [common.iter.cust]

friend constexpr iter_rvalue_reference_t<I> iter_move(const common_iterator& i) noexcept(noexcept(ranges::iter_move(declval<const I&>()))) requires input_iterator<I>;
Preconditions: holds_alternative<I>(i.v_) is true.
Effects: Equivalent to: return ranges​::​iter_move(get<I>(i.v_));
template<indirectly_swappable<I> I2, class S2> friend constexpr void iter_swap(const common_iterator& x, const common_iterator<I2, S2>& y) noexcept(noexcept(ranges::iter_swap(declval<const I&>(), declval<const I2&>())));
Preconditions: holds_alternative<I>(x.v_) and holds_alternative<I2>(y.v_) are each true.
Effects: Equivalent to ranges​::​iter_swap(get<I>(x.v_), get<I2>(y.v_)).