C++ 检查枚举标志

Question

在我的一个类中，我有一个整数，它存储一组枚举标志，如下所示：

enum AttackFlags
{
    Contact = 1,                        //Move connects with target
    Projectile = 2,                         //Attack is projectile based
    Unblockable = 4,                        //Attack can not be blocked
    UncounterableLv1 = 8,                   //Attack can't be countered except by extreme counter attack skills/status effects
    UncounterableLv2 = 16,                  //Attack can not be countered
    Flinches = 32,                          //Has a chance to stun the enemy, pushing back their next turn
    Unreflectable = 64,                     //Attack penetrates reflect. Only checked for Magic attacks
    IgnoreDefenderStatusEffects = 128,      //Ignores active status effects on the defender
    IgnoreAttackerStatusEffects = 256,      //Ignores active status effects on the attacker
    IgnoreDefenderAbilities = 512,          //Ignore the defenders abilities
    IgnoreAttackerAbilities = 1024,         //Ignore the attackers abilities
    IgnoreArmorRating = 2048,               //Ignore the defensive boosts of armor
    IgnoreWeaponRating = 4096,              //Ignore the attack boost from weapons
    HighCritical = 8192,                    //The move has an increased chance to crit
    CausesStatus = 16384,                   //Can the move cause status effects?
    Elemental = 32768,                      //Is the move elemental based?
    Unimplemented = 65536,                  //has the move been implemented yet?
    ModsTimer = 131072,                     //Does it have an effect on the target or users timer?
    Heals = 262144,                         //Does the move heal?
    SecondaryEffects = 524288,              //Attack has additional effects besides basic attack
    PhysicalAttackFlag = 1048576,           //Is the Class Physically based? I.E. blocked by Protect and Shield
    MagicAttackFlag = 2097152,              //Is the move Magically Based? I.E. is it affected by things like Shell
    MultiHit = 4194304,                     //Does it enxcapsulate more then 1 hit
    SingleUse = 8388608,                    //Attack can only be used once per battle
    DoesNotCauseDamage = 16777216
};

class Attack
{
   int AtkFlags; //Stores AttackFlags |'d together

}

我想向我的 Attack 类添加一个具有以下签名的方法

bool HasAttackFlags(int flags);

flags 将有许多 AttackFlags |'d 一起。如果我只想检查一个标志，我可以将 & AtkFlags 和标志放在一起，但是因为我必须检查多个可能的标志，所以这不起作用。如何正确检查多个标志？我想避免传递一个向量/一组标志来检查，因为简单地|将一组标志放在一起比构造一个向量/组更简单

提前致谢

编辑：

为了澄清我的意思，我可能有以下内容

Attack atk;
atk.AtkFlags = Contact | Projectile | Heals | MagicAttackFlag;

然后，我想像这样检查 atk 上的标志：

bool res = atk.HasAttackFlags(Contact | Projectile);

res 应该为真，反之亦然

bool res = atk.HasAttackFlags(Contact | Unreflectable);

应该是假的，因为 AtkFlags 不包含 Contact 和 Unreflectable。

Answer 1

我不确定我是否在关注您的问题，因为您似乎提到了明显的解决方案。那么作为解决方案有什么问题，显然添加您希望的任何其他标志：

bool HasAttackFlags(int flags) {
    return (flags&(contact|projectile))!=0;
}

编辑：哦...我想我刚刚想通了，你想检查是否存在 2 个或更多标志作为一组？在这种情况下，您可以简单地将方法修改为：

bool HasAttackFlags(int flags) {
    return (flags&(contact|projectile))==(contact|projectile);
}

Answer 2

这是我的建议：

注意使用枚举定义来启用机器

enum AttackFlags
{
    Contact                     = 1ul <<  0,  // Move connects with target
    Projectile                  = 1ul <<  1,  // Attack is projectile based
    Unblockable                 = 1ul <<  2,  // Attack can not be blocked
    UncounterableLv1            = 1ul <<  3,  // Attack can't be countered except by extreme counter attack skills/status effects
    UncounterableLv2            = 1ul <<  4,  // Attack can not be countered
    Flinches                    = 1ul <<  5,  // Has a chance to stun the enemy, pushing back their next turn
    Unreflectable               = 1ul <<  6,  // Attack penetrates reflect. Only checked for Magic attacks
    IgnoreDefenderStatusEffects = 1ul <<  7,  // Ignores active status effects on the defender
    IgnoreAttackerStatusEffects = 1ul <<  8,  // Ignores active status effects on the attacker
    IgnoreDefenderAbilities     = 1ul <<  9,  // Ignore the defenders abilities
    IgnoreAttackerAbilities     = 1ul << 10,  // Ignore the attackers abilities
    IgnoreArmorRating           = 1ul << 11,  // Ignore the defensive boosts of armor
    IgnoreWeaponRating          = 1ul << 12,  // Ignore the attack boost from weapons
    HighCritical                = 1ul << 13,  // The move has an increased chance to crit
    CausesStatus                = 1ul << 14,  // Can the move cause status effects?
    Elemental                   = 1ul << 15,  // Is the move elemental based?
    Unimplemented               = 1ul << 16,  // has the move been implemented yet?
    ModsTimer                   = 1ul << 17,  // Does it have an effect on the target or users timer?
    Heals                       = 1ul << 18,  // Does the move heal?
    SecondaryEffects            = 1ul << 19,  // Attack has additional effects besides basic attack
    PhysicalAttackFlag          = 1ul << 20,  // Is the Class Physically based? I.E. blocked by Protect and Shield
    MagicAttackFlag             = 1ul << 21,  // Is the move Magically Based? I.E. is it affected by things like Shell
    MultiHit                    = 1ul << 22,  // Does it enxcapsulate more then 1 hit
    SingleUse                   = 1ul << 23,  // Attack can only be used once per battle
    DoesNotCauseDamage          = 1ul << 24, 

    MaskAttack      = MagicAttackFlag | PhysicalAttackFlag,
    MaskIgnore      = IgnoreWeaponRating | IgnoreArmorRating | IgnoreAttackerAbilities | IgnoreDefenderAbilities | IgnoreAttackerStatusEffects,
    // etc
};

static bool HasAttackFlag(AttackFlags flags)
{
    return flags & MaskAttack;
}

static bool HasIgnoreFlag(AttackFlags flags)
{
    return flags & MaskIgnore;
}

作为额外的奖励，考虑一种仅返回“杂项”（可以说是未屏蔽）标志的方法：

static AttackFlags MiscFlags(AttackFlags flags)
{
    return (AttackFlags) (flags & ~(MaskAttack | MaskIgnore));
}

Answer 3

例如，您可以这样做：

int v = Unblockable | UncounterableLv1| UncounterableLv;
if ((flags & v ) == v)
{
  //flags has all three: Unblockable, UncounterableLv1 and UncounterableLv
}
else if ( (flags & v ) ==  (Unblockable | UncounterableLv1))
{
  //flags has Unblockable and UncounterableLv1
}
else if ( (flags & v ) ==  Unblockable )
{
  //flags has Unblockable only
}
//and so on