#[derive(Debug)]enumFruit{Apple,Banana,}implFruit{fncall(&self){println!("{:?}",self);//self表示枚举值}fnuse1(&self)->u8{matchself{Fruit::Apple=>{println!("This is apple");1},Fruit::Banana=>2,}}}fnmain(){println!("enum examples");letx=Fruit::Apple;x.call();lety=Fruit::...
impl Default for Menu { fn default() -> Self { Self { items: Vec::new() } } } #[derive(Debug, Clone)] #[non_exhaustive] pub struct Submenu { pub title: String, pub enabled: bool, pub inner: Menu, } impl Submenu { /// Creates a new submenu with the given title and menu i...
use std::str::FromStr; use regex::Regex; pub trait Parse { type Error; // 关联类型 fn parse(s: &str) -> Result<Self, Self::Error> // 返回关联类型Error where Self: Sized; } impl<T> Parse for T where T: FromStr + Default, { // 实现关联类型 Error 为 String type Error = ...
枚举和结构之间还有另外一个相似之处:正如我们可以使用impl在结构上定义方法一样,我们也可以在枚举上定义方法。 这是一个可以在Message枚举中定义的名为call的方法: fnmain() {enumMessage{ Quit, Move { x:i32, y:i32},Write(String),ChangeColor(i32,i32,i32), }implMessage{fncall(&self) {//注意self...
enumCommand{Input(Input), Exit, }pubenumRequestStatus{Completed(Response), Running, }pubstructParser{ command_sender: Sender, response_receiver: Receiver<(Input, Response)>, cached_result: HashMap , }implParser{pubfnnew()->Self{let(command_sender, command_receiver) = channel::();let(response...
Default应该为&Enum返回什么？记住，引用必须指向一些有效的数据，并且不使所述数据保持活动。因此，即使...
枚举类型对于 Java 程序员来说不会陌生，它是列举常量成员的非常好用的工具。在 rust 中也同样如此，...
阅读编译器/linter消息，它们会告诉您具体的操作：
impl std::fmt::DebugforComplex{fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result{letreal_default =Real::default;ifself.imaginary == real_default {write!(f,"{}",self.real)}elseifself.real == real_default {write!(f,"{}i",self.imaginary)}elseifself.imaginary...
{ pub static ref STDOUT: Arc<Stdout> = Default::default(); } /// 控制台输出 #[derive(Default)] pub struct Stdout; impl INode for Stdout { fn write_at(&self, offset: usize, buf: &[u8]) -> Result<usize> { if offset != 0 { Err(FsError::NotSupported) } else if let Ok(stri...