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);