template<class ForwardIterator>
bool is_sorted(ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator>
bool is_sorted(ExecutionPolicy&& exec,
ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
bool is_sorted(ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
bool is_sorted(ExecutionPolicy&& exec,
ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ForwardIterator>
ForwardIterator is_sorted_until(ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator is_sorted_until(ExecutionPolicy&& exec,
ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
ForwardIterator is_sorted_until(ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
ForwardIterator is_sorted_until(ExecutionPolicy&& exec,
ForwardIterator first, ForwardIterator last,
Compare comp);
Returns: Если (last - first) < 2, вернется last. В противном случае, возвращает последний итератор i в [first, last] течение которого диапазон [first, i) сортируется.