int * Find(int * start, int * end, int val)
{
    for ( auto it = start; it != end; ++it )
    {
        if ( *it == val )
            return it;
    }
    return end; // wasn't found
}

int main()
{
    int arr [] = {1, 2, 5, 2, 7 ,8};
    auto pos = Find(begin(arr), end(arr), 2);
    if ( pos != end(arr) )
        cout << *pos << " found";
    else
        cout << "not found";
    
    // After modifications:
    /*
    std::list<int> l{1,6,2,7,0,9};
    auto val = assignment::find(begin(l), end(l),
                                [](int i) { return i % 2 == 0; });
    if ( val != end(l) )
        cout << "First even number: " << *val << endl;
    */
}