std::ranges::cartesian_product_view<First, Vs...>::end

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C++
Ranges library
Range adaptors
std::ranges::cartesian_product_view
Member functions
cartesian_product_view::end
Deduction guides
Iterator
Member functions
Non-member functions
constexpr iterator< false > end( )

requires ( ( ! /*simple-view*/ <First> || ... || ! /*simple-view*/ <Vs> ) &&

/*cartesian-product-is-common*/ <First, Vs...> ) ;
(1) (since C++23)
constexpr iterator< true > end( ) const
    requires /*cartesian-product-is-common*/ < const First, const Vs...> ;
(2) (since C++23)
constexpr std::default_sentinel_t end( ) const noexcept ;
(3) (since C++23)

Returns an iterator or a sentinel representing the end of the cartesian_product_view

Let bases_ be the underlying tuple of views.

1,2) Equivalent to
auto check = [ ] ( auto & rng) { return __begin_or_first_end(rng) ; } ;
return iterator<__is_const> ( /*tuple-transform*/ (check, bases_) ) ;
where:
  • __is_const is true for the const-qualified overload, and false
  • __is_empty is true if the expression ranges::empty(rng) is true for any rng among the underlying ranges except the first one and false
  • __begin_or_first_end(rng) is expression-equivalent to __is_empty ? ranges::begin (rng) : /*cartesian-common-arg-end*/ (rng) if rng is the first underlying range and ranges::begin(rng)
3) Equivalent to: return std::default_sentinel;

Parameters

(none)

Return value

An iterator to the element following the last element, or a sentinel which compares equal to the end iterator.

Example

Run this code
#include <array>
#include <format>
#include <iostream>
#include <ranges>
#include <string_view>
#include <tuple>
using namespace std::literals;
 
int main()
{
    constexpr auto a = std::array{ "bool"sv, "goto"sv, "extern"sv, "long"sv }; /*
                                       ^         ^           ^         ^        */
    constexpr auto v = std::ranges::cartesian_product_view(a[0], a[1], a[2], a[3]);
 
    constexpr std::tuple<char const&,
                         char const&,
                         char const&,
                         char const&> last{*(v.end() - 1)};
 
    std::cout << std::format("{}{}{}{}{}",
                             std::get<0>(last),
                             std::get<1>(last),
                             std::get<2>(last),
                             std::get<3>(last), '\n');
}

Output: 

long

See also

 returns an iterator to the beginning
(public member function)
(C++20)
 returns a sentinel indicating the end of a range
(customization point object)
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