update at 2021-11-28 22:42:16 by ehlxr
parent
0bd3c40620
commit
aef2137ec8
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@ -0,0 +1,562 @@
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use core::fmt;
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use std::cell::RefCell;
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use std::collections::HashMap;
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use std::fmt::{Display, Formatter};
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use std::fs::File;
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use std::io::{self, Read};
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use std::ops::Deref;
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use std::rc::{Rc, Weak};
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#[derive(Debug)]
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pub struct Point1<T, U> {
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pub x: T,
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pub y: U,
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}
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impl<D, Z> Point1<D, Z> {
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pub fn x(&self) -> &D {
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&self.x
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}
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}
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impl Point1<i32, i32> {
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pub fn y(&self) -> i32 {
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self.y
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}
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}
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impl<T, U> Point1<T, U> {
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pub fn mixup<V, W>(self, p: Point1<V, W>) -> Point1<T, W> {
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Point1 { x: self.x, y: p.y }
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}
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}
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pub fn test_tuple(t: (i32, &str)) {
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println!("{} {}", t.0, t.1);
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}
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pub static mut COUNTER: u32 = 0;
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pub fn add_to_count(inc: u32) {
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unsafe {
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COUNTER += inc;
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}
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}
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#[derive(Debug)]
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pub struct Bt {
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pub height: u32,
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pub label: Option<String>,
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}
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#[derive(Debug)]
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pub struct SelectBox {
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pub width: u32,
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pub height: u32,
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pub options: Vec<String>,
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}
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impl Draw for SelectBox {
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fn draw(&self) {
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// code to actually draw a select box
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println!("{:?}", self);
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}
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}
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#[derive(Debug)]
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pub struct Button {
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pub width: u32,
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pub height: u32,
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pub label: String,
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}
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impl Draw for Button {
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fn draw(&self) {
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// 实际绘制按钮的代码
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println!("{:?}", self);
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}
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}
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pub struct Screen {
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pub components: Vec<Box<dyn Draw>>,
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}
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impl Screen {
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pub fn run(&self) {
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for component in self.components.iter() {
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component.draw();
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}
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}
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}
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pub trait Draw {
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fn draw(&self);
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}
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pub struct MyBox<T>(T);
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impl<T> MyBox<T> {
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pub fn new(x: T) -> MyBox<T> {
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MyBox(x)
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}
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}
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impl<T> Deref for MyBox<T> {
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type Target = T;
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fn deref(&self) -> &T {
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&self.0
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}
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}
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pub fn hello_str(name: &str) {
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println!("Hello, {}!", name);
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}
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#[derive(Debug)]
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pub enum List {
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Cons(i32, RefCell<Rc<List>>),
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Nil,
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}
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impl List {
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pub fn tail(&self) -> Option<&RefCell<Rc<List>>> {
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use crate::List::*;
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match self {
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Cons(_, item) => Some(item),
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Nil => None,
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}
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}
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}
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#[derive(Debug)]
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pub struct Node {
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pub value: i32,
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pub parent: RefCell<Weak<Node>>,
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pub children: RefCell<Vec<Rc<Node>>>,
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}
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pub fn change(some_string: &mut String) {
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some_string.push_str(", world");
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}
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//enum IpAddrKind {
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// V4,
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// V6,
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//}
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#[derive(Debug)]
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pub enum IpAddr {
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V4(u8, u8, u8, u8),
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V6(String),
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}
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pub enum Color {
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_Rgb(i32, i32, i32),
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Hsv(i32, i32, i32),
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}
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pub enum Msg {
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_Quit,
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ChangeColor(Color),
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}
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// Quit 没有关联任何数据。
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// Move 包含一个匿名结构体。
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// Write 包含单独一个 String。
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// ChangeColor 包含三个 i32。
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#[derive(Debug)]
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pub enum Message {
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Quit,
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Move { x: i32, y: i32 },
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Write(String),
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ChangeColor(i32, i32, i32),
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}
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impl Message {
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pub fn call(&self) {
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println!("this message call.");
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}
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}
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#[derive(Debug)]
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pub struct Rectangle {
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pub width: u32,
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pub height: u32,
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}
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impl Rectangle {
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pub fn area(&self) -> u32 {
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self.width * self.height
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}
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pub fn can_hold(&self, other: &Rectangle) -> bool {
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self.width > other.width && self.height > other.height
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}
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pub fn square(size: u32) -> Rectangle {
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Rectangle {
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width: size,
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height: size,
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}
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}
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}
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mod sound {
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pub mod instrument {
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pub fn clarinet() {
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println!("this clarinet");
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}
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}
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}
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pub mod performance_group {
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pub use crate::sound::instrument;
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pub fn clarinet_trio() {
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instrument::clarinet();
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instrument::clarinet();
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instrument::clarinet();
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}
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}
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/// 传播错误
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pub fn read_username_from_file(path: &str) -> Result<String, io::Error> {
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// 1.
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// let f = File::open(path);
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//
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// let mut f = match f {
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// Ok(file) => file,
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// Err(error) => return Err(error),
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// };
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//
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// let mut s = String::new();
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// match f.read_to_string(&mut s) {
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// Ok(_) => Ok(s),
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// Err(e) => Err(e),
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// }
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// 2.
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let mut f = File::open(path)?;
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let mut s = String::new();
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f.read_to_string(&mut s)?;
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Ok(s)
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// 3.
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// let mut s = String::new();
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// File::open(path)?.read_to_string(&mut s)?;
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// Ok(s)
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// 4.
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// fs::read_to_string(path)
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}
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pub trait Summary {
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fn summarize_author(&self) -> String;
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fn summarize(&self) -> String {
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format!("(Read more from {}...)", self.summarize_author())
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}
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}
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#[derive(Debug)]
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pub struct Tweet {
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pub username: String,
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pub content: String,
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pub reply: bool,
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pub retweet: bool,
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}
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impl Summary for Tweet {
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fn summarize_author(&self) -> String {
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format!("@{}", self.username)
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}
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}
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// impl ToString for Tweet {
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// fn to_string(&self) -> String {
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// format!("{:?}", self)
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// }
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// }
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impl Display for Tweet {
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fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
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write!(
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f,
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"Tweet username: {}, content: {}",
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self.username, self.content
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)
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}
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}
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//fn notify<T: Summary + ToString, U: Summary>(t: &T, u: &U) -> String {
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// format!("{}, {}", u.summarize(), t.to_string())
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//}
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//fn notify(t: &(impl Summary + ToString), u: &(impl Summary)) -> String {
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// format!("{}, {}", u.summarize(), t.to_string())
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//}
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pub fn notify<T, U>(t: &T, u: &U) -> String
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where
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T: Summary + ToString,
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U: Summary,
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{
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format!("{}, {}", u.summarize(), t.to_string())
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}
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// 返回实现了指定 trait 的方法
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pub fn returns_summarizable() -> impl Summary {
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Tweet {
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username: String::from("horse_ebooks"),
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content: String::from("of course, as you probably already know, people"),
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reply: false,
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retweet: false,
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}
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}
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pub fn largest<T: PartialOrd + Copy>(list: &[T]) -> T {
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//fn largest(list: &[impl PartialOrd + Copy]) -> impl PartialOrd + Copy {
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//fn largest<T>(list: &[T]) -> T
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// where T: PartialOrd + Copy {
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let mut largest = list[0];
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for &item in list.iter() {
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if item > largest {
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largest = item;
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}
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}
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// for item in list.iter() {
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// if *item > largest {
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// largest = *item;
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// }
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// }
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return largest;
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}
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pub fn largest2<T: PartialOrd>(list: &[T]) -> &T {
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let mut largest = &list[0];
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for item in list.iter() {
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if item > largest {
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largest = item;
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}
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}
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return largest;
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}
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#[derive(Debug)]
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pub struct Pair<T> {
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x: T,
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y: T,
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}
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impl<T> Pair<T> {
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pub fn new(x: T, y: T) -> Self {
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Self { x, y }
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}
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}
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// 只有那些为 T 类型实现了 PartialOrd trait（来允许比较）和 Display trait（来启用打印）的 Pair<T> 才会实现 cmp_display 方法
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impl<T: Display + PartialOrd> Pair<T> {
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pub fn cmp_display(&self) {
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if self.x >= self.y {
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println!("The largest member is x = {}", self.x);
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} else {
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println!("The largest member is y = {}", self.y);
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}
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}
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}
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pub fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
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if x.len() > y.len() {
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x
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} else {
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y
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}
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}
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// struct Cacher<T>
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// where
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// T: Fn(u32) -> u32,
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// {
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// calculation: T,
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// value: Option<u32>,
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// }
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//
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// impl<T> Cacher<T>
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// where
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// T: Fn(u32) -> u32,
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// {
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// fn new(calculation: T) -> Cacher<T> {
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// Self {
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// calculation,
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// value: None,
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// }
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// }
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//
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// fn value(&mut self, args: u32) -> u32 {
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// match self.value {
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// Some(&v) => v,
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// None => {
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// let v = (self.calculation)(args);
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// v
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// }
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// }
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// }
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// }
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pub struct Cacher<T, K, V>
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where
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T: Fn(&K) -> V,
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{
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pub calculation: T,
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pub value: HashMap<K, V>,
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}
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use core::hash::Hash;
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impl<T, K, V> Cacher<T, K, V>
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where
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V: Copy,
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K: Hash + Eq,
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T: Fn(&K) -> V,
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{
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pub fn new(calculation: T) -> Cacher<T, K, V> {
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Self {
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calculation,
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value: HashMap::<K, V>::new(),
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}
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}
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pub fn value(&mut self, args: K) -> V {
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let value = &mut self.value;
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match value.get(&args) {
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Some(&v) => v,
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None => {
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let x = (self.calculation)(&args);
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let x1 = x.clone();
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value.insert(args, x);
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x1
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}
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}
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// match self.value.get(&args) {
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// Some(&v) => v,
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// None => {
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// let x = (self.calculation)(&args);
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// let x1 = x.clone();
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// self.value.insert(args, x);
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// x1
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// }
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// }
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}
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}
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#[derive(Debug)]
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pub struct Shoe {
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pub size: u32,
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pub style: String,
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}
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pub fn shoes_in_my_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
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shoes
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// .iter() // a collection of type `std::vec::Vec<Shoe>` cannot be built from `std::iter::Iterator<Item=&Shoe>`
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.into_iter() //获取 vector 所有权的迭代器
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.filter(|s| s.size == shoe_size)
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.collect()
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}
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pub struct Counter {
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count: u32,
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}
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impl Counter {
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pub fn new() -> Counter {
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Counter { count: 0 }
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}
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}
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impl Iterator for Counter {
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type Item = u32;
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fn next(&mut self) -> Option<Self::Item> {
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self.count += 1;
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if self.count < 6 {
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Some(self.count)
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} else {
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None
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}
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}
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}
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pub trait Messenger {
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fn send(&self, msg: &str);
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}
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pub struct LimitTracker<'a, T: Messenger> {
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messenger: &'a T,
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value: usize,
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max: usize,
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}
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impl<'a, T> LimitTracker<'a, T>
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where
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T: Messenger,
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{
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pub fn new(messenger: &'a T, max: usize) -> LimitTracker<T> {
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LimitTracker {
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messenger,
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value: 0,
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max,
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}
|
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}
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pub fn set_value(&mut self, value: usize) {
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self.value = value;
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let percentage_of_max = self.value as f64 / self.max as f64;
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if percentage_of_max >= 1.0 {
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self.messenger.send("Error: You are over your quota!");
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} else if percentage_of_max >= 0.9 {
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self.messenger
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.send("Urgent warning: You've used up over 90% of your quota!");
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} else if percentage_of_max >= 0.75 {
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self.messenger
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.send("Warning: You've used up over 75% of your quota!");
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||||
}
|
||||
}
|
||||
}
|
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|
||||
pub trait Pilot {
|
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fn fly(&self);
|
||||
}
|
||||
|
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pub trait Wizard {
|
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fn fly(&self);
|
||||
}
|
||||
|
||||
pub struct Human;
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||||
|
||||
impl Pilot for Human {
|
||||
fn fly(&self) {
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println!("This is your captain speaking.");
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||||
}
|
||||
}
|
||||
|
||||
impl Wizard for Human {
|
||||
fn fly(&self) {
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println!("Up!");
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||||
}
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||||
}
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|
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impl Human {
|
||||
pub fn fly(&self) {
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println!("*waving arms furiously*");
|
||||
}
|
||||
}
|
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564
src/main.rs
564
src/main.rs
|
|
@ -4,12 +4,12 @@ mod tests;
|
|||
mod user;
|
||||
|
||||
use std::cell::RefCell;
|
||||
use std::hash::Hash;
|
||||
use std::ops::Deref;
|
||||
use std::rc::{Rc, Weak};
|
||||
use std::sync::{mpsc, Arc, Mutex};
|
||||
use std::time::Duration;
|
||||
use std::{collections::HashMap, fmt::Display, fs::File, io, io::ErrorKind, thread};
|
||||
use std::{collections::HashMap, fs::File, io::ErrorKind, thread};
|
||||
|
||||
use rust_study::*;
|
||||
|
||||
fn main() {
|
||||
let mut s = String::from("Hello");
|
||||
|
|
@ -1084,561 +1084,3 @@ fn main() {
|
|||
// person.fly();
|
||||
Human::fly(&person);
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Point1<T, U> {
|
||||
x: T,
|
||||
y: U,
|
||||
}
|
||||
|
||||
impl<D, Z> Point1<D, Z> {
|
||||
fn x(&self) -> &D {
|
||||
&self.x
|
||||
}
|
||||
}
|
||||
|
||||
impl Point1<i32, i32> {
|
||||
fn y(&self) -> i32 {
|
||||
self.y
|
||||
}
|
||||
}
|
||||
|
||||
impl<T, U> Point1<T, U> {
|
||||
fn mixup<V, W>(self, p: Point1<V, W>) -> Point1<T, W> {
|
||||
Point1 { x: self.x, y: p.y }
|
||||
}
|
||||
}
|
||||
|
||||
fn test_tuple(t: (i32, &str)) {
|
||||
println!("{} {}", t.0, t.1);
|
||||
}
|
||||
|
||||
static mut COUNTER: u32 = 0;
|
||||
|
||||
fn add_to_count(inc: u32) {
|
||||
unsafe {
|
||||
COUNTER += inc;
|
||||
}
|
||||
}
|
||||
|
||||
use core::fmt;
|
||||
use std::fmt::Formatter;
|
||||
use std::io::Read;
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Bt {
|
||||
height: u32,
|
||||
label: Option<String>,
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct SelectBox {
|
||||
width: u32,
|
||||
height: u32,
|
||||
options: Vec<String>,
|
||||
}
|
||||
|
||||
impl Draw for SelectBox {
|
||||
fn draw(&self) {
|
||||
// code to actually draw a select box
|
||||
println!("{:?}", self);
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
pub struct Button {
|
||||
pub width: u32,
|
||||
pub height: u32,
|
||||
pub label: String,
|
||||
}
|
||||
|
||||
impl Draw for Button {
|
||||
fn draw(&self) {
|
||||
// 实际绘制按钮的代码
|
||||
println!("{:?}", self);
|
||||
}
|
||||
}
|
||||
|
||||
pub struct Screen {
|
||||
pub components: Vec<Box<dyn Draw>>,
|
||||
}
|
||||
|
||||
impl Screen {
|
||||
pub fn run(&self) {
|
||||
for component in self.components.iter() {
|
||||
component.draw();
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub trait Draw {
|
||||
fn draw(&self);
|
||||
}
|
||||
|
||||
struct MyBox<T>(T);
|
||||
|
||||
impl<T> MyBox<T> {
|
||||
fn new(x: T) -> MyBox<T> {
|
||||
MyBox(x)
|
||||
}
|
||||
}
|
||||
|
||||
impl<T> Deref for MyBox<T> {
|
||||
type Target = T;
|
||||
|
||||
fn deref(&self) -> &T {
|
||||
&self.0
|
||||
}
|
||||
}
|
||||
|
||||
fn hello_str(name: &str) {
|
||||
println!("Hello, {}!", name);
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
enum List {
|
||||
Cons(i32, RefCell<Rc<List>>),
|
||||
Nil,
|
||||
}
|
||||
|
||||
impl List {
|
||||
fn tail(&self) -> Option<&RefCell<Rc<List>>> {
|
||||
use crate::List::*;
|
||||
match self {
|
||||
Cons(_, item) => Some(item),
|
||||
Nil => None,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Node {
|
||||
value: i32,
|
||||
parent: RefCell<Weak<Node>>,
|
||||
children: RefCell<Vec<Rc<Node>>>,
|
||||
}
|
||||
|
||||
fn change(some_string: &mut String) {
|
||||
some_string.push_str(", world");
|
||||
}
|
||||
|
||||
//enum IpAddrKind {
|
||||
// V4,
|
||||
// V6,
|
||||
//}
|
||||
|
||||
#[derive(Debug)]
|
||||
enum IpAddr {
|
||||
V4(u8, u8, u8, u8),
|
||||
V6(String),
|
||||
}
|
||||
|
||||
enum Color {
|
||||
_Rgb(i32, i32, i32),
|
||||
Hsv(i32, i32, i32),
|
||||
}
|
||||
|
||||
enum Msg {
|
||||
_Quit,
|
||||
ChangeColor(Color),
|
||||
}
|
||||
|
||||
// Quit 没有关联任何数据。
|
||||
// Move 包含一个匿名结构体。
|
||||
// Write 包含单独一个 String。
|
||||
// ChangeColor 包含三个 i32。
|
||||
#[derive(Debug)]
|
||||
enum Message {
|
||||
Quit,
|
||||
Move { x: i32, y: i32 },
|
||||
Write(String),
|
||||
ChangeColor(i32, i32, i32),
|
||||
}
|
||||
|
||||
impl Message {
|
||||
fn call(&self) {
|
||||
println!("this message call.");
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Rectangle {
|
||||
width: u32,
|
||||
height: u32,
|
||||
}
|
||||
|
||||
impl Rectangle {
|
||||
fn area(&self) -> u32 {
|
||||
self.width * self.height
|
||||
}
|
||||
|
||||
fn can_hold(&self, other: &Rectangle) -> bool {
|
||||
self.width > other.width && self.height > other.height
|
||||
}
|
||||
|
||||
fn square(size: u32) -> Rectangle {
|
||||
Rectangle {
|
||||
width: size,
|
||||
height: size,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
mod sound {
|
||||
pub mod instrument {
|
||||
pub fn clarinet() {
|
||||
println!("this clarinet");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
mod performance_group {
|
||||
pub use crate::sound::instrument;
|
||||
|
||||
pub fn clarinet_trio() {
|
||||
instrument::clarinet();
|
||||
instrument::clarinet();
|
||||
instrument::clarinet();
|
||||
}
|
||||
}
|
||||
|
||||
/// 传播错误
|
||||
fn read_username_from_file(path: &str) -> Result<String, io::Error> {
|
||||
// 1.
|
||||
// let f = File::open(path);
|
||||
//
|
||||
// let mut f = match f {
|
||||
// Ok(file) => file,
|
||||
// Err(error) => return Err(error),
|
||||
// };
|
||||
//
|
||||
// let mut s = String::new();
|
||||
// match f.read_to_string(&mut s) {
|
||||
// Ok(_) => Ok(s),
|
||||
// Err(e) => Err(e),
|
||||
// }
|
||||
|
||||
// 2.
|
||||
let mut f = File::open(path)?;
|
||||
|
||||
let mut s = String::new();
|
||||
f.read_to_string(&mut s)?;
|
||||
Ok(s)
|
||||
|
||||
// 3.
|
||||
// let mut s = String::new();
|
||||
// File::open(path)?.read_to_string(&mut s)?;
|
||||
// Ok(s)
|
||||
|
||||
// 4.
|
||||
// fs::read_to_string(path)
|
||||
}
|
||||
|
||||
trait Summary {
|
||||
fn summarize_author(&self) -> String;
|
||||
|
||||
fn summarize(&self) -> String {
|
||||
format!("(Read more from {}...)", self.summarize_author())
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Tweet {
|
||||
pub username: String,
|
||||
pub content: String,
|
||||
pub reply: bool,
|
||||
pub retweet: bool,
|
||||
}
|
||||
|
||||
impl Summary for Tweet {
|
||||
fn summarize_author(&self) -> String {
|
||||
format!("@{}", self.username)
|
||||
}
|
||||
}
|
||||
|
||||
// impl ToString for Tweet {
|
||||
// fn to_string(&self) -> String {
|
||||
// format!("{:?}", self)
|
||||
// }
|
||||
// }
|
||||
|
||||
impl Display for Tweet {
|
||||
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"Tweet username: {}, content: {}",
|
||||
self.username, self.content
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
//fn notify<T: Summary + ToString, U: Summary>(t: &T, u: &U) -> String {
|
||||
// format!("{}, {}", u.summarize(), t.to_string())
|
||||
//}
|
||||
|
||||
//fn notify(t: &(impl Summary + ToString), u: &(impl Summary)) -> String {
|
||||
// format!("{}, {}", u.summarize(), t.to_string())
|
||||
//}
|
||||
|
||||
fn notify<T, U>(t: &T, u: &U) -> String
|
||||
where
|
||||
T: Summary + ToString,
|
||||
U: Summary,
|
||||
{
|
||||
format!("{}, {}", u.summarize(), t.to_string())
|
||||
}
|
||||
|
||||
// 返回实现了指定 trait 的方法
|
||||
fn returns_summarizable() -> impl Summary {
|
||||
Tweet {
|
||||
username: String::from("horse_ebooks"),
|
||||
content: String::from("of course, as you probably already know, people"),
|
||||
reply: false,
|
||||
retweet: false,
|
||||
}
|
||||
}
|
||||
|
||||
fn largest<T: PartialOrd + Copy>(list: &[T]) -> T {
|
||||
//fn largest(list: &[impl PartialOrd + Copy]) -> impl PartialOrd + Copy {
|
||||
//fn largest<T>(list: &[T]) -> T
|
||||
// where T: PartialOrd + Copy {
|
||||
let mut largest = list[0];
|
||||
|
||||
for &item in list.iter() {
|
||||
if item > largest {
|
||||
largest = item;
|
||||
}
|
||||
}
|
||||
|
||||
// for item in list.iter() {
|
||||
// if *item > largest {
|
||||
// largest = *item;
|
||||
// }
|
||||
// }
|
||||
|
||||
return largest;
|
||||
}
|
||||
|
||||
fn largest2<T: PartialOrd>(list: &[T]) -> &T {
|
||||
let mut largest = &list[0];
|
||||
|
||||
for item in list.iter() {
|
||||
if item > largest {
|
||||
largest = item;
|
||||
}
|
||||
}
|
||||
|
||||
return largest;
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Pair<T> {
|
||||
x: T,
|
||||
y: T,
|
||||
}
|
||||
|
||||
impl<T> Pair<T> {
|
||||
fn new(x: T, y: T) -> Self {
|
||||
Self { x, y }
|
||||
}
|
||||
}
|
||||
|
||||
// 只有那些为 T 类型实现了 PartialOrd trait（来允许比较）和 Display trait（来启用打印）的 Pair<T> 才会实现 cmp_display 方法
|
||||
impl<T: Display + PartialOrd> Pair<T> {
|
||||
fn cmp_display(&self) {
|
||||
if self.x >= self.y {
|
||||
println!("The largest member is x = {}", self.x);
|
||||
} else {
|
||||
println!("The largest member is y = {}", self.y);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
|
||||
if x.len() > y.len() {
|
||||
x
|
||||
} else {
|
||||
y
|
||||
}
|
||||
}
|
||||
|
||||
// struct Cacher<T>
|
||||
// where
|
||||
// T: Fn(u32) -> u32,
|
||||
// {
|
||||
// calculation: T,
|
||||
// value: Option<u32>,
|
||||
// }
|
||||
//
|
||||
// impl<T> Cacher<T>
|
||||
// where
|
||||
// T: Fn(u32) -> u32,
|
||||
// {
|
||||
// fn new(calculation: T) -> Cacher<T> {
|
||||
// Self {
|
||||
// calculation,
|
||||
// value: None,
|
||||
// }
|
||||
// }
|
||||
//
|
||||
// fn value(&mut self, args: u32) -> u32 {
|
||||
// match self.value {
|
||||
// Some(&v) => v,
|
||||
// None => {
|
||||
// let v = (self.calculation)(args);
|
||||
// v
|
||||
// }
|
||||
// }
|
||||
// }
|
||||
// }
|
||||
|
||||
struct Cacher<T, K, V>
|
||||
where
|
||||
T: Fn(&K) -> V,
|
||||
{
|
||||
calculation: T,
|
||||
value: HashMap<K, V>,
|
||||
}
|
||||
|
||||
impl<T, K, V> Cacher<T, K, V>
|
||||
where
|
||||
V: Copy,
|
||||
K: Hash + Eq,
|
||||
T: Fn(&K) -> V,
|
||||
{
|
||||
fn new(calculation: T) -> Cacher<T, K, V> {
|
||||
Self {
|
||||
calculation,
|
||||
value: HashMap::<K, V>::new(),
|
||||
}
|
||||
}
|
||||
|
||||
fn value(&mut self, args: K) -> V {
|
||||
let value = &mut self.value;
|
||||
|
||||
match value.get(&args) {
|
||||
Some(&v) => v,
|
||||
None => {
|
||||
let x = (self.calculation)(&args);
|
||||
let x1 = x.clone();
|
||||
value.insert(args, x);
|
||||
x1
|
||||
}
|
||||
}
|
||||
|
||||
// match self.value.get(&args) {
|
||||
// Some(&v) => v,
|
||||
// None => {
|
||||
// let x = (self.calculation)(&args);
|
||||
// let x1 = x.clone();
|
||||
// self.value.insert(args, x);
|
||||
// x1
|
||||
// }
|
||||
// }
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug)]
|
||||
struct Shoe {
|
||||
size: u32,
|
||||
style: String,
|
||||
}
|
||||
|
||||
fn shoes_in_my_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
|
||||
shoes
|
||||
// .iter() // a collection of type `std::vec::Vec<Shoe>` cannot be built from `std::iter::Iterator<Item=&Shoe>`
|
||||
.into_iter() //获取 vector 所有权的迭代器
|
||||
.filter(|s| s.size == shoe_size)
|
||||
.collect()
|
||||
}
|
||||
|
||||
struct Counter {
|
||||
count: u32,
|
||||
}
|
||||
|
||||
impl Counter {
|
||||
fn new() -> Counter {
|
||||
Counter { count: 0 }
|
||||
}
|
||||
}
|
||||
|
||||
impl Iterator for Counter {
|
||||
type Item = u32;
|
||||
|
||||
fn next(&mut self) -> Option<Self::Item> {
|
||||
self.count += 1;
|
||||
|
||||
if self.count < 6 {
|
||||
Some(self.count)
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub trait Messenger {
|
||||
fn send(&self, msg: &str);
|
||||
}
|
||||
|
||||
pub struct LimitTracker<'a, T: Messenger> {
|
||||
messenger: &'a T,
|
||||
value: usize,
|
||||
max: usize,
|
||||
}
|
||||
|
||||
impl<'a, T> LimitTracker<'a, T>
|
||||
where
|
||||
T: Messenger,
|
||||
{
|
||||
pub fn new(messenger: &'a T, max: usize) -> LimitTracker<T> {
|
||||
LimitTracker {
|
||||
messenger,
|
||||
value: 0,
|
||||
max,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn set_value(&mut self, value: usize) {
|
||||
self.value = value;
|
||||
|
||||
let percentage_of_max = self.value as f64 / self.max as f64;
|
||||
|
||||
if percentage_of_max >= 1.0 {
|
||||
self.messenger.send("Error: You are over your quota!");
|
||||
} else if percentage_of_max >= 0.9 {
|
||||
self.messenger
|
||||
.send("Urgent warning: You've used up over 90% of your quota!");
|
||||
} else if percentage_of_max >= 0.75 {
|
||||
self.messenger
|
||||
.send("Warning: You've used up over 75% of your quota!");
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
trait Pilot {
|
||||
fn fly(&self);
|
||||
}
|
||||
|
||||
trait Wizard {
|
||||
fn fly(&self);
|
||||
}
|
||||
|
||||
struct Human;
|
||||
|
||||
impl Pilot for Human {
|
||||
fn fly(&self) {
|
||||
println!("This is your captain speaking.");
|
||||
}
|
||||
}
|
||||
|
||||
impl Wizard for Human {
|
||||
fn fly(&self) {
|
||||
println!("Up!");
|
||||
}
|
||||
}
|
||||
|
||||
impl Human {
|
||||
fn fly(&self) {
|
||||
println!("*waving arms furiously*");
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue