25 Iterators library [iterators]

25.5 Iterator adaptors [predef.iterators]

25.5.5 Common iterators [iterators.common]

25.5.5.3 Constructors and conversions [common.iter.const]

constexpr common_iterator(I i);
Effects: Initializes v_ as if by v_{in_place_type<I>, std​::​move(i)}.
constexpr common_iterator(S s);
Effects: Initializes v_ as if by v_{in_place_type<S>, std​::​move(s)}.
template<class I2, class S2> requires convertible_to<const I2&, I> && convertible_to<const S2&, S> constexpr common_iterator(const common_iterator<I2, S2>& x);
Preconditions: x.v_.valueless_by_exception() is false.
Effects: Initializes v_ as if by v_{in_place_index<i>, get<i>(x.v_)}, where i is x.v_.index().
template<class I2, class S2> requires convertible_to<const I2&, I> && convertible_to<const S2&, S> && assignable_from<I&, const I2&> && assignable_from<S&, const S2&> constexpr common_iterator& operator=(const common_iterator<I2, S2>& x);
Preconditions: x.v_.valueless_by_exception() is false.
Effects: Equivalent to:
  • If v_.index() == x.v_.index(), then get<i>(v_) = get<i>(x.v_).
  • Otherwise, v_.emplace<i>(get<i>(x.v_)).
where i is x.v_.index().
Returns: *this.