template<class InputIterator, class T>
constexpr InputIterator find(InputIterator first, InputIterator last,
const T& value);
template<class ExecutionPolicy, class ForwardIterator, class T>
ForwardIterator find(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last,
const T& value);
template<class InputIterator, class Predicate>
constexpr InputIterator find_if(InputIterator first, InputIterator last,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
ForwardIterator find_if(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last,
Predicate pred);
template<class InputIterator, class Predicate>
constexpr InputIterator find_if_not(InputIterator first, InputIterator last,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
ForwardIterator find_if_not(ExecutionPolicy&& exec, ForwardIterator first, ForwardIterator last,
Predicate pred);