//#(compile) c++; compiler:g132; options:-O3 -std=c++23; libs:-
// https://godbolt.org/z/91jj8Toqs
#include <vector>
#include <iostream>
// … adjacent_pair von oben hier …
int main() {
std::vector v{1,2,3,4};
auto f = [](auto a, auto b) { std::cout << (a+b) << ' '; };
adjacent_pair(v.begin(), v.end(), f); // 3 5 7
std::cout << '\n';
std::vector x{4,8};
adjacent_pair(x.begin(), x.end(), f); // 12
std::cout << '\n';
std::vector w{4};
adjacent_pair(w.begin(), w.end(), f); // nichts
std::cout << '\n';
std::vector<int> y{};
adjacent_pair(y.begin(), y.end(), f); // nichts
std::cout << '\n';
}