#pragma once

#include <iterator>

namespace algorithm
{
// comp returns true if lhs is thought to be less than rhs
// f(start, end)
template <typename InputIt, typename Compare, typename F>
void operate_on_set_intervals(InputIt first, InputIt last, Compare comp, F f)
{
    if (first == last) return;
    for (InputIt prev_iter = first++; first != last; ++first, ++prev_iter) {
        if (comp(*prev_iter, *first)) f(*prev_iter, *first);
    }
}

// f(start, end)
template <typename InputIt, typename F>
void operate_on_set_intervals(InputIt first, InputIt last, F f)
{
    operate_on_set_intervals(first, last, std::less<std::decay_t<decltype(*first)>>{}, f);
}
} // namespace algorithm