#include <ranges>
#include <vector>
#include <iostream>
int main() {
// (1) デフォルトコンストラクタ
std::ranges::adjacent_transform_view<
std::ranges::empty_view<int>,
decltype([](int, int) { return 0; }),
2
> atv1;
// (2) 元となるRangeと変換関数を受け取るコンストラクタ
std::vector<int> v = {1, 2, 3, 4, 5};
auto diff = [](int x, int y) { return y - x; };
std::ranges::adjacent_transform_view<std::views::all_t<std::vector<int>&>, decltype(diff), 2> atv2(v, diff);
for (int d : atv2) {
std::cout << d << " ";
}
std::cout << std::endl;
}