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

💖 NAME 💖

std::ranges::zip_transform_view::iterator — that's the whole name, bestie, it's literally std::ranges::zip_transform_view::iterator, iconic and long and we respect it 🎀

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✨ Synopsis ✨

template< bool Const >  (since C++23)
class /*iterator*/;     (exposition only*)

Ok so picture this: it's the iterator type of a possibly const-qualified zip_transform_view, and you get one back from zip_transform_view::begin and, in certain cases, from zip_transform_view::end. Slay.

And the tea on the template param: the type /*iterator*/<true> or /*iterator*/<false> treats the underlying views as const-qualified or non-const-qualified respectively. That's the whole vibe check right there 🦋

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🌸 Member types 🌸

• Parent (private) — zip_transform_view if Const is false, const zip_transform_view otherwise. (exposition-only member type*)
• Base (private) — InnerView if Const is false, const InnerView otherwise. (exposition-only member type*)

Bestie, before we go any further, two little "let" definitions that everything else leans on:

Let /*maybe-const*/<Const, F>& denote const F& if Const is true, F& otherwise.

Let /*maybe-const*/<Const, Views> denote const Views if Const is true, Views otherwise.

Let /*POT*/ denote the pack of types std::iterator_traits<std::iterator_t</*maybe-const*/<Const, Views>>>::iterator_category...

Now the actual members:

• iterator_category (optional) — this one has layers, ok? Hold my hand:

If /*Base*/ models forward_range, then iterator_category denotes:

• std::input_iterator_tag, if std::invoke_result_t</*maybe-const*/<Const, F>&, ranges::range_reference_t</*maybe-const*/<Const, Views>>...> is not a reference.
• Otherwise,
  • std::random_access_iterator_tag, if (std::derived_from</*POT*/, std::random_access_iterator_tag> && ...) is true.
  • Otherwise, std::bidirectional_iterator_tag, if (std::derived_from</*POT*/, std::bidirectional_iterator_tag> && ...) is true.
  • Otherwise, std::forward_iterator_tag, if (std::derived_from</*POT*/, std::forward_iterator_tag> && ...) is true.
  • Otherwise, std::input_iterator_tag.

Heads up: it is not present if /*Base*/ does not model forward_range. Not me showing up with no iterator_category, embarrassing 💀

• iterator_concept — /*ziperator*/<Const>::iterator_concept. That's it, that's the definition 🫶
• value_type — let /*RREF*/ be ranges::range_reference_t<Views>..., and /*CRREF*/ be ranges::range_reference_t<const Views>.... Then:
  • std::remove_cvref_t<std::invoke_result_t<F&, /*RREF*/>> if Const is false,
  • std::remove_cvref_t<std::invoke_result_t<const F&, /*CRREF*/>> otherwise.
• difference_type — range::range_difference_t</*Base*/>> — well, exactly range::range_difference_t</*Base*/> 👑

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🦋 Data members 🦋

• parent_ (private) — a pointer Parent* to the parent object. (exposition-only member object*)
• inner_ (private) — an iterator of type ziperator<Const>. (exposition-only member type*)

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💅 Member functions 💅

• constructor (C++23) — constructs an iterator. (public member function)
• operator* (C++23) — obtains the result of applying the invocable object to the underlying pointed-to elements. (public member function)
• operator[] (C++23) — obtains the result of applying the invocable object to the underlying elements at given offset. (public member function)
• operator++, operator++(int), operator--, operator--(int), operator+=, operator-= (C++23) — advances or decrements the underlying iterator. (public member function)

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🔥 Non-member functions 🔥

• operator==, operator<=> (C++23) — compares the underlying iterators. (function)
• operator+, operator- (C++23) — performs iterator arithmetic on underlying iterators. (function)

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🥺 Example 🥺

This section is incomplete.

Reason: no example.

Not the "no example" arc 😭 we're all rooting for you, example section. You'll get there.

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🍓 Category 🍓

• Todo no example

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Lowkey a whole journey, ngl — but you ate that, bestie 💜 This gem came straight from http://cppreference.com, dated 2024.06.10, on the std::ranges...ew::iterator(3) page in the C++ Standard Library manual. Go forth and zip-transform, you main character ✨🌈👑