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std::ranges::lazy_split_view<V, Pattern>::outer_iterator 

template< bool Const >
struct /*outer_iterator*/;
 (1) (since C++20)

The return type of lazy_split_view::begin, and of lazy_split_view::end when the underlying view is a common_range and forward_range.

If either V or Pattern is not a simple view (e.g. if ranges::iterator_t<const V> is invalid or different from ranges::iterator_t<V>), Const is true for iterators returned from the const overloads, and false otherwise. If V is a simple view, Const is true if and only if V is a forward_range.

The name of this class template (shown here as /*outer_iterator*/) is unspecified.

Member types

Member type Definition
Parent (private) const ranges::lazy_split_view if Const is true, otherwise ranges::lazy_split_view. The name is for exposition only.
Base (private) const V if Const is true, otherwise V. The name is for exposition only.
iterator_concept (C++20) std::forward_iterator_tag if Base models forward_range, otherwise std::input_iterator_tag.
iterator_category (C++20) std::input_iterator_tag if Base models forward_range. Not present otherwise.
value_type (C++20) ranges::lazy_iterator_view<V, Pattern>::/*outer_iterator*/<Const>::value_type
difference_type (C++20) ranges::range_difference_t<Base>.

Data members

Typical implementations of outer_iterator hold two or three non-static data members:

  • A pointer of type Parent* to the parent lazy_split_view object (shown here as parent_ for exposition only).
  • An iterator of type ranges::iterator_t<Base> (shown here as current_ for exposition only) into the underlying view; present only if V models forward_range.
  • A boolean flag (shown here as trailing_empty_ for exposition only) that indicates whether an empty trailing subrange (if any) was reached.

Member functions

(constructor)
(C++20)
 constructs an iterator
(public member function)
operator*
(C++20)
 returns the current subrange
(public member function)
operator++operator++(int)
(C++20)
 advances the iterator
(public member function)
cur
(C++20)
 returns conditionally a reference to the current_ (if present) or to the *parent_->current_
(exposition-only member function)

Member functions

std::ranges::lazy_split_view::outer_iterator::outer_iterator 

/*outer_iterator*/() = default;
 (1) (since C++20) 
constexpr explicit /*outer_iterator*/( Parent& parent )
  requires (!ranges::forward_range<Base>);
 (2) (since C++20) 
constexpr /*outer_iterator*/( Parent& parent, ranges::iterator_t<Base> current )
  requires ranges::forward_range<Base>;
 (3) (since C++20) 
constexpr /*outer_iterator*/( /*outer_iterator*/<!Const> i )
  requires Const && std::convertible_to<ranges::iterator_t<V>,
                                        ranges::iterator_t<Base>>;
 (4) (since C++20)
1) Value initializes the exposition-only non-static data members with their default member initializer, that is:
  • parent_ = nullptr;,
  • current_ = iterator_t<Base>(); (present only if V models forward_range),
2) Initializes parent_ with std::addressof(parent).
3) Initializes parent_ with std::addressof(parent) and current_ with std::move(current).
4) Initializes parent_ with i.parent_ and current_ with std::move(i.current_).

The exposition-only non-static data member trailing_empty_ is initialized with its default member initializer to false.

std::ranges::lazy_split_view::outer_iterator::operator*

constexpr value_type operator*() const;
 (since C++20)

Equivalent to return value_type{*this};.

std::ranges::lazy_split_view::outer_iterator::operator++

constexpr /*outer_iterator*/& operator++();
 (1) (since C++20) 
constexpr decltype(auto) operator++(int);
 (2) (since C++20)
1) The function body is equivalent to 
const auto end = ranges::end(parent_->base_);
if (/*cur*/() == end)
{
    trailing_empty_ = false;
    return *this;
}
const auto [pbegin, pend] = ranges::subrange { parent_->pattern_ };
if (pbegin == pend)
    ++/*cur*/();
else if constexpr (/*tiny_range*/<Pattern>)
{
    /*cur*/() = ranges::find(std::move(/*cur*/()), end, *pbegin);
    if (/*cur*/() != end)
    {
        ++/*cur*/();
        if (/*cur*/() == end)
            trailing_empty_ = true;
    }
}
else
{
    do
    {
        auto [b, p] = ranges::mismatch(/*cur*/(), end, pbegin, pend);
        if (p == pend)
        {
            /*cur*/() = b;
            if (/*cur*/() == end)
                trailing_empty_ = true;
            break; // The pattern matched; skip it
        }
    } while (++/*cur*/() != end);
}
return *this;
2) Equivalent to 
if constexpr (ranges::forward_range<Base>)
{
    auto tmp = *this;
    ++*this;
    return tmp;
}
else
{
    ++*this; // no return statement
}

std::ranges::lazy_split_view::outer_iterator::cur()

constexpr auto& /*cur*/() noexcept;          // exposition only
 (1) (since C++20) 
constexpr auto& /*cur*/() const noexcept;    // exposition only
 (2) (since C++20)

This exposition-only convenience member function is referred to from /*outer_iterator*/::operator++(), from the non-member operator==(const /*outer_iterator*/&, std::default_sentinel_t), and from some member functions of the possible implementation of inner_iterator.

1,2) Equivalent to 
if constexpr (ranges::forward_range<V>)
    return current_;
else
    return *parent->current_;

Non-member functions

operator==
(C++20)
 compares the underlying iterators or the underlying iterator and std::default_sentinel
(function)

operator==(std::ranges::split_view::outer_iterator) 

friend constexpr bool operator==( const /*outer_iterator*/& x,
                                  const /*outer_iterator*/& y )
      requires forward_range<Base>;
 (1) (since C++20) 
friend constexpr bool operator==( const /*outer_iterator*/& x,
                                  std::default_sentinel_t );
 (2) (since C++20)
1) Equivalent to return x.current_ == y.current_ and x.trailing_empty_ == y.trailing_empty_;.
2) Equivalent to return x./*cur*/() == ranges::end(x.parent_->base_) and !x.trailing_empty_;.

The != operator is synthesized from operator==.

These functions are not visible to ordinary unqualified or qualified lookup, and can only be found by argument-dependent lookup when std::ranges::split_view::outer_iterator is an associated class of the arguments.

Nested classes

(C++20)
 the value type of the outer_iterator
(public member class)

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