parsing.cc

enum class Direction {
    Right,
    Left,
    Up,
    Down
};

struct Order {
    Direction direction;
    uint32_t count;
    
    friend std::istream& operator>>(std::istream& s, Order& order) {
        char dir;
        if (s >> dir >> order.count) switch (dir) {
            case 'D': order.direction = Direction::Down; break;
            case 'U': order.direction = Direction::Up; break;
            case 'L': order.direction = Direction::Left; break;
            case 'R': order.direction = Direction::Right; break;
            default: throw std::runtime_error("Can't parse Order, wrong direction.");
        }
        return s;
    }
};

// Overloading the stream extraction operator enables the use
// std::views::istream and a simple copy.
std::vector<Order> data;
std::ranges::copy(std::views::istream<Order>(file), std::back_inserter(data));