在数据类型为class的列表中查找elem

def find_elem_in_class_list(class_list, elem):
    for item in class_list:
        if isinstance(item, type):
            if item == elem:
                return item
    return None

public static <T> T findElemInClassList(List<?> classList, Class<T> elem) {
    for (Object item : classList) {
        if (item.getClass() == elem) {
            return elem.cast(item);
        }
    }
    return null;
}

template<class T>
T* findElemInClassList(const std::vector<void*>& classList) {
    for (void* item : classList) {
        if (dynamic_cast<T*>(item)) {
            return static_cast<T*>(item);
        }
    }
    return nullptr;
}