std::ranges::adjacent_transform_view<V,F,N>:: begin

From cppreference.com
C++
Ranges library
Range adaptors
std::ranges::adjacent_transform_view
Member functions
adjacent_transform_view::begin
Iterator
Member functions
Non-member functions
Sentinel
Member functions
Non-member functions
constexpr auto begin ( ) ;
(1) (since C++23)
constexpr auto begin ( ) const

requires ranges:: range < const InnerView > &&
std:: regular_invocable < const F & ,

/*REPEAT*/ ( ranges:: range_reference_t < const V > , N ) ... > ;
(2) (since C++23)

Returns an iterator to the first element of the adjacent_transform_view .

Let inner_ be the underlying ranges::adjacent_view .

1) Equivalent to return /*iterator*/ < false > ( * this, inner_. begin ( ) ) ; .
2) Equivalent to return /*iterator*/ < true > ( * this, inner_. begin ( ) ) ; .

Parameters

(none)

Return value

Iterator to the first element.

Example

Run this code 
#include <ranges>
 
int main()
{
    auto sum = [](auto... args) { return (... + args); };
 
    constexpr auto view = std::views::iota(13, 1337)
                        | std::views::adjacent_transform<3>(sum);
 
    static_assert(*view.begin() == 42 and 42 == 13 + 14 + 15);
}

See also

returns an iterator or a sentinel to the end
(public member function)
(C++20)
returns an iterator to the beginning of a range
(customization point object)
Retrieved from " https://en.cppreference.com/mwiki/index.php?title=cpp/ranges/adjacent_transform_view/begin&oldid=172657 "