优化：枚举

public enum Role
{
    Son = 0,
    Father = 1,
    Husband = 2,
    A = 4,
    Mother = 8,
    D = 16,
    B = 32,
    C = 64,
}

可优化成：

[Flags]
public enum Role
{
    Son = 0,
    Father = 1 << 0,//1
    Husband = 1 << 1,//2
    A = 1 << 2,//4
    Mother = 1 << 3,//8
    D = 1 << 4,//16
    B = 1 << 5,//32
    C = 1 << 6,//64
}

优点是：不用算2的次方。

【Flags】特性表示：该枚举可以进行位运算。