::equal

#include <functional>
#include <iterator>

template<typename ForwardIt, typename Compare>
bool equal(ForwardIt first, ForwardIt last, Compare compare) {

    if(first == last) {
        return true;
    }

    ForwardIt next = std::next(first);

    while(next != last) {
        if(compare(*first, *next)) {
            ++first;
            ++next;
        } else {
            return false;
        }
    }

    return true;

}

template<typename ForwardIt>
bool equal(ForwardIt first, ForwardIt last) {
    return ::equal(first, last, std::equal_to<>{ });
}