std::ranges::concat_view<Views...>::end
requires (!(/*simple-view*/<Views> && ...));
requires (ranges::range <const Views> && ...) &&
Returns an iterator or std::default_sentinel that compares equal to the past-the-end iterator of the concat_view.
constexpr auto N = sizeof...(Views);
if constexpr (ranges::common_range <Views...[N - 1]>) return iterator <false>(this, std::in_place_index <N - 1>, ranges::end (std::get<N - 1>(views_ )));
else return std::default_sentinel ;
constexpr auto N = sizeof...(Views);
if constexpr (ranges::common_range <const Views...[N - 1]>) return iterator <true>(this, std::in_place_index <N - 1>, ranges::end (std::get<N - 1>(views_ )));
else return std::default_sentinel ;
[edit] Return value
As described above.
[edit] Example
The preliminary version can be checked out on Compiler Explorer.
#include <concepts> #include <iterator> #include <ranges> int main() { static constexpr int p[]{37, 42, 69}; static constexpr auto q = {19937, 1729}; constexpr auto cat = std::ranges::views::concat (p, q); static_assert(not std::same_as <std::default_sentinel_t, decltype(cat.end())>); static_assert(cat.end()[-1] == 1729); }