template<class ForwardIterator>
ForwardIterator adjacent_find(ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator adjacent_find(ExecutionPolicy&& exec,
ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class BinaryPredicate>
ForwardIterator adjacent_find(ForwardIterator first, ForwardIterator last,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator, class BinaryPredicate>
ForwardIterator adjacent_find(ExecutionPolicy&& exec,
ForwardIterator first, ForwardIterator last,
BinaryPredicate pred);