外部ライブラリを使用せずに C でフラグ列挙型を実装するにはどうすればよいですか?

enum AnimalFlags {
    HasClaws = 1,
    CanFly = 2,
    EatsFish = 4,
    Endangered = 8
};

int seahawkFlags = CanFly | EatsFish | Endangered;

enum AnimalFlags {
    HasClaws = 1,
    CanFly = 2,
    EatsFish = 4,
    Endangered = 8
};

inline AnimalFlags operator|(AnimalFlags a, AnimalFlags b) {
    return static_cast<AnimalFlags>(static_cast<int>(a) | static_cast<int>(b));
}

// Define other operators as needed

int seahawkFlags = animalFlags::CanFly | AnimalFlags::EatsFish | AnimalFlags::Endangered;