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Variants

std::ranges:: views:: zip_transform, std::ranges:: zip_transform_view

From cppreference.net
C++
Ranges library
Range adaptors
std::ranges::zip_transform_view
Member functions
Deduction guides
Iterator
Member functions
Non-member functions
Sentinel
Member functions
Non-member functions
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 > ... > &&
/*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... >>
(1) (since C++23)
namespace views {

inline constexpr /*unspecified*/ zip_transform = /*unspecified*/ ;

}
(2) (since C++23)
Call signature
template < class F, ranges:: viewable_range ... Rs >

requires /* see below */

constexpr auto zip_transform ( F && f, Rs && ... rs ) ;
(since C++23)
1) zip_transform_view is a range adaptor that takes an invocable object and one or more view s , 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:

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.

Contents

Customization point objects

The name views::zip_transform denotes a customization point object , which is a const function object of a literal semiregular class type. See CustomizationPointObject for details.

Member functions

constructs a zip_transform_view
(public member function)
returns an iterator to the beginning
(public member function)
returns an iterator or a sentinel to the end
(public member function)
returns the number of elements, provided only if each underlying (adapted) range satisfies sized_range
(public member function)
Inherited from std::ranges::view_interface
returns whether the derived view is empty, provided only if it satisfies sized_range or forward_range
(public member function of std::ranges::view_interface<D> )
(C++23)
returns a constant iterator to the beginning of the range
(public member function of std::ranges::view_interface<D> )
(C++23)
returns a sentinel for the constant iterator of the range
(public member function of std::ranges::view_interface<D> )
returns whether the derived view is not empty, provided only if ranges::empty is applicable to it
(public member function of std::ranges::view_interface<D> )
returns the first element in the derived view, provided if it satisfies forward_range
(public member function of std::ranges::view_interface<D> )
returns the last element in the derived view, provided only if it satisfies bidirectional_range and common_range
(public member function of std::ranges::view_interface<D> )
returns the n th element in the derived view, provided only if it satisfies 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* )
ziperator (private)
zentinel (private)

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

the iterator type
( exposition-only member class template* )
the sentinel type used when the underlying zip_view is not a common_range
( exposition-only member class template* )

Notes

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

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