#include <cassert>
#include <concepts>
#include <list>
#include <ranges>
#include <tuple>
#include <utility>
#include <vector>
int main()
{
auto v = std::vector{0, 1, 2, 3, 4, 5};
auto i = (v | std::views::adjacent<3>).begin();
using I = decltype(i);
static_assert(std::same_as<I::value_type, std::tuple<int, int, int>>);
static_assert(std::same_as<I::iterator_concept, std::random_access_iterator_tag>);
// some of available operators:
++i; i++; --i; i--; i += 2; i -= 2;
assert(i[2] == std::tuple(2, 3, 4));
using DI = decltype(*i);
static_assert(std::same_as<DI, std::tuple<int&, int&, int&>>);
std::get<1>(*i) = 42; // modifies v[1] via iterator i
assert(v[1] == 42);
auto l = std::list{0, 1, 2, 3, 4, 5};
auto j = (l | std::views::adjacent<3>).begin();
using J = decltype(j);
static_assert(std::same_as<J::value_type, std::tuple<int, int, int>>);
static_assert(std::same_as<J::iterator_concept, std::bidirectional_iterator_tag>);
++j; --j; j++; j--; // some of available operators
// j += 2; j -= 2; // error: these operator are not available
// std::ignore() = j[1]; // for bidirectional iterator
}