初始化 Rust 结构的问题

Question

制作纸牌游戏来学习 Rust。初始化我的结构时遇到问题。

enum Effect {
    Passive,
    EarnEffect,
    ChargeEffect,
}

struct EarnEffect {
    amount: i8,
    per: Option<Tag>,
}

struct Card {
    effect: Effect
}

已经尝试过以下方法：

Card { effect: Effect::EarnEffect { amount: 1, per: None }}

和

Card { effect: EarnEffect { amount: 1, per: None }}

Answer 1

你的枚举变量和你的结构是两个独立的实体，即使你给了它们相同的名字。

enum Effect {
    Passive,
    EarnEffect,
    ChargeEffect,
}

明确表示枚举可以有 3 个可能的值，没有额外的数据。您可以将数据与枚举变量相关联

enum Effect {
    Passive,
    // Struct-like syntax
    EarnEffect {
      amount: i8,
      // ...
    },
    ChargeEffect,
}

或

enum Effect {
    Passive,
    // Tuple-like syntax
    EarnEffect(i8),
    ChargeEffect,
}

您需要使用枚举结构变体，或者将您的结构作为元组变体的数据。目前你有一些不匹配的东西。

选项 1

enum Effect {
    Passive,
    EarnEffect {
        amount: i8,
        per: Option<Tag>,
    },
    ChargeEffect,
}

struct Card {
    effect: Effect
}

与

Card { effect: Effect::EarnEffect { amount: 1, per: None }}

选项 2

enum Effect {
    Passive,
    EarnEffect(EarnEffect),
    ChargeEffect,
}

struct EarnEffect {
    amount: i8,
    per: Option<Tag>,
}

struct Card {
    effect: Effect
}

与

Card { effect: Effect::EarnEffect(EarnEffect { amount: 1, per: None }) }