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) Equivalent to
auto check = [](auto& rng) { return __begin_or_first_end(rng); };
return iterator<__is_const>(/*tuple-transform*/(check, bases_));,
return iterator<__is_const>(/*tuple-transform*/(check, bases_));,
where:
- __is_const is true for the const-qualified overload, and false otherwise.
- __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 otherwise.
- __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) otherwise.
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) |