std::ranges::views::zip_transform,std::ranges::zip_transform_view(3)

NAME
std::ranges::views::zip_transform,std::ranges::zip_transform_view - std::ranges::views::zip_transform,std::ranges::zip_transform_view

Synopsis
   Defined in header <ranges>
   template< std::move_constructible F, ranges::input_range... Views
   >
       requires (ranges::view<Views> && ...) && (sizeof...(Views) >
   0) &&
                 std::is_object_v<F> && std::regular_invocable<
                     F&, ranges::range_reference_t<Views>...> && (1) (since C++23)
                 /*can-reference*/<std::invoke_result_t<
                     F&, ranges::range_reference_t<Views>...>>
   class zip_transform_view
        : public ranges::view_interface<zip_transform_view<F,
   Views...>>
   namespace views {
       inline constexpr /*unspecified*/ zip_transform = (2) (since C++23)
   /*unspecified*/;
   }
   Call signature
   template< class F, ranges::viewable_range... Rs >
       requires /* see below */ (since C++23)
   constexpr auto zip_transform( F&& f, Rs&&... rs );
   1) zip_transform_view is a range adaptor that takes an invocable object and one or
   more views, and produces a view whose i^th element is the result of applying the
   invocable object to the i^th elements of all views.
   A type T models the exposition-only concept /*can-reference*/ if and only if T& is a
   valid type.
   2) views::zip_transform is a customization point object.
   When calling with one argument f, let FD be std::decay_t<decltype(f)>, if:
     * FD models copy_constructible,
     * FD& models regular_invocable, and
     * std::invoke_result_t<FD&> is an object type,
   then views::zip_transform(f) is expression-equivalent to ((void)f,
   auto(views::empty<std::decay_t<std::invoke_result_t<FD&>>>)). Otherwise, the call to
   views::zip_transform is ill-formed.
   When calling with more than one arguments f and rs..., views::zip_transform(f,
   rs...) is expression-equivalent to ranges::zip_transform_view(f, rs...).
   zip_transform_view models the concepts random_access_range, bidirectional_range,
   forward_range, input_range, common_range, and sized_range when the underlying
   ranges::zip_view<Views...> models respective concepts.

Member functions
   constructor constructs a zip_transform_view
   (C++23) (public member function)
   begin returns an iterator to the beginning
   (C++23) (public member function)
   end returns an iterator or a sentinel to the end
   (C++23) (public member function)
   size returns the number of elements. Provided only if each underlying
   (C++23) (adapted) range satisfies sized_range.
                 (public member function)
         Inherited from std::ranges::view_interface
   empty returns whether the derived view is empty. Provided if it satisfies
   (C++20) sized_range or forward_range.
                 (public member function of std::ranges::view_interface<D>)
   cbegin returns a constant iterator to the beginning of the range.
   (C++23) (public member function of std::ranges::view_interface<D>)
   cend returns a sentinel for the constant iterator of the range.
   (C++23) (public member function of std::ranges::view_interface<D>)
   operator bool returns whether the derived view is not empty. Provided if
   (C++20) ranges::empty is applicable to it.
                 (public member function of std::ranges::view_interface<D>)
   front returns the first element in the derived view. Provided if it
   (C++20) satisfies forward_range.
                 (public member function of std::ranges::view_interface<D>)
   back returns the last element in the derived view. Provided if it satisfies
   (C++20) bidirectional_range and common_range.
                 (public member function of std::ranges::view_interface<D>)
   operator[] returns the n^th element in the derived view. Provided if it satisfies
   (C++20) random_access_range.
                 (public member function of std::ranges::view_interface<D>)
   Deduction guides

Member types
   Member type Definition
   InnerView (private) ranges::zip_view<Views...>.
                       (exposition-only member type*)
                        * ranges::iterator_t<const InnerView> if Const is true,
   ziperator (private) otherwise
                        * ranges::iterator_t<InnerView>.
                        (exposition-only member type*)
                        * ranges::sentinel_t<const InnerView> if Const is true,
   zentinel (private) otherwise
                        * ranges::sentinel_t<InnerView>.
                        (exposition-only member type*)
   Data members
   Member object Definition
   zip_ (private) An underlying view object of type InnerView
                  (exposition-only member object*)
   fun_ (private) A wrapped invocable object of type movable-box<F>
                  (exposition-only member object*)
   Nested classes
   iterator the iterator type
   (C++23) (exposition-only member class template*)
   sentinel the sentinel type used when the underlying zip_view is not a common_range
   (C++23) (exposition-only member class template*)

Notes
    Feature-test macro Value Std Feature
                        std::ranges::zip_view,
   __cpp_lib_ranges_zip 202110L (C++23) std::ranges::zip_transform_view,
                        std::ranges::adjacent_view,
                        std::ranges::adjacent_transform_view

Example
// Run this code
 #include <array>
 #include <iostream>
 #include <list>
 #include <ranges>
 #include <vector>
 void print(auto const rem, auto const& r)
 {
     std::cout << rem << '{';
     for (char o[]{0,' ',0}; auto const& e : r)
         std::cout << o << e, *o = ',';
     std::cout << "}\n";
 }
 int main()
 {
     auto v1 = std::vector<float>{1, 2, 3};
     auto v2 = std::list<short>{1, 2, 3, 4};
     auto v3 = std::to_array({1, 2, 3, 4, 5});
     auto add = [](auto a, auto b, auto c) { return a + b + c; };
     auto sum = std::views::zip_transform(add, v1, v2, v3);
     print("v1: ", v1);
     print("v2: ", v2);
     print("v3: ", v3);
     print("sum: ", sum);
 }

Output:
 v1: {1, 2, 3}
 v2: {1, 2, 3, 4}
 v3: {1, 2, 3, 4, 5}
 sum: {3, 6, 9}

See also
   ranges::zip_view a view consisting of tuples of references to corresponding
   views::zip elements of the adapted views
   (C++23) (class template) (customization point object)
   ranges::transform_view a view of a sequence that applies a transformation function
   views::transform to each element
   (C++20) (class template) (range adaptor object)
   ranges::elements_view takes a view consisting of tuple-like values and a number N
   views::elements and produces a view of N^th element of each tuple
   (C++20) (class template) (range adaptor object)