std::ranges...or::iterator(3)

NAME 🎀

Okay bestie, welcome to the C++ Standard Libary manual page for std::ranges...or::iterator(3) — and the NAME section is doing that iconic double-tap: std::ranges::chunk_view::iterator::iterator — std::ranges::chunk_view::iterator::iterator. That's the name, and the description is literally the same thing. periodt. 💅

Synopsis ✨

This is the constructor synopsis, and every line, every requires, and every little annotation is staying exactly as it appears. No cap. 🦋

          /*iterator*/() = default;                                     (1)
       (since C++23)
          constexpr /*iterator*/( /*iterator*/<!Const> i )

              requires
                  Const and
                  std::convertible_to<ranges::iterator_t<V>,            (2)
       (since C++23)
          ranges::iterator_t<Base>> and

                  std::convertible_to<ranges::sentinel_t<V>,
          ranges::sentinel_t<Base>>;
          private:

          constexpr /*iterator*/( Parent* parent,
                                  ranges::iterator_t<Base> current,     (3)
       (exposition only*)

                                  ranges::range_difference_t<Base>
          missing = 0 );

Construct an iterator. That's the whole mood of this page: we're constructing an iterator, and there are three flavors. 🫶

1. Default constructor — /*iterator*/() = default; is (1), and it's (since C++23). It value-initializes the underlying data members:
   • current_ with ranges::iterator_t<Base>()
   • end_ with ranges::sentinel_t<Base>()
   • n_ with 0
   • missing_ with 0
2. Conversion constructor — constexpr /*iterator*/( /*iterator*/<!Const> i ) is (2), and it's also (since C++23). It converts from /*iterator*/<false> to /*iterator*/<true>. Its requires clause is:
   • Const and
   • std::convertible_to<ranges::iterator_t<V>, ranges::iterator_t<Base>> and
   • std::convertible_to<ranges::sentinel_t<V>, ranges::sentinel_t<Base>>

It initializes the underlying data members:

• current_ with std::move(i.current_)
• end_ with std::move(i.end_)
• n_ with i.n_
• missing_ with i.missing_

3. Private constructor — item (3), marked (exposition only*). It's the private one used by ranges::chunk_view::begin and ranges::chunk_view::end. The missing parameter defaults to 0. This constructor is not accessible to users — read it and weep, lol. 😭 It initializes the underlying data members:
   • current_ with current
   • end_ with ranges::end(parent->base_)
   • n_ with parent->n_
   • missing_ with missing

Wait, did we lose the missing = 0 default? Nope — it's right there in the constructor signature and it's staying. 🫶

Parameters 🎀

• i — an /*iterator*/<false>
• parent — a pointer to owning chunk_view
• current — an iterator to the begin of current chunk
• missing — a difference between expected (n_) and actual size of current chunk

Example 💀

This section is incomplete Reason: no example

Category 👑

• Todo no example

Mwah 💋 — source/version: http://cppreference.com; date: 2024.06.10; page: std::ranges...or::iterator(3). Stay hydrated and keep those iterators constructed. 💖