std::ranges::cartesian_product_view<First, Vs...>::end
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< cpp | ranges | cartesian product view
constexpr iterator<false> end() requires ((!__simple_view<First> || ... || !__simple_view<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) Let:
- __is_const be true for the const-qualified overload, and false otherwise;
- __is_empty be true if the expression ranges::empty(rng) is true for any rng among the underlying ranges except the first one and false otherwise; and
- __begin_or_first_end(rng) be expression-equivalent to __is_empty ? ranges::begin(rng) : __cartesian_common_arg_end(rng) if rng is the first underlying range and ranges::begin(rng) otherwise.
Equivalent to:
auto check = [](auto& rng) { return __begin_or_first_end(rng); }; return iterator<__is_const>(__tuple_transform(check, bases_));
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
Can be checked online with Compiler Explorer.
Run this code
#include <array> #include <print> #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::println("{}{}{}{}", std::get<0>(last), std::get<1>(last), std::get<2>(last), std::get<3>(last)); }
Output:
long
See also
(C++23) |
returns an iterator to the beginning (public member function) |
(C++20) |
returns a sentinel indicating the end of a range (customization point object) |