[package]
+name="hello_cargo"
+version="0.1.0"
+edition="2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
[package]
+name="guessing_game"
+version="0.1.0"
+edition="2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rand="0.3.14"
+
fnmain(){
+println!("Hello, world!");
+annother_function(5,6);// arugment is 5 and 6
+}
+
+fnannother_function(x: i32,y: i32){
+// parameter is x and y
+println!("the value of x is: {}",x);
+println!("the value of y is: {}",y);
+}
+
fnmain(){
+letnumber=6;
+ifnumber%4==0{
+print!("{} is divisible by 4",number);
+}elseifnumber%3==0{
+print!("{} is divisible by 3",number);
+}elseifnumber%2==0{
+print!("{} is divisible by 2",number);
+}else{
+print!("{} is not divisible by 4, 3, or 2",number);
+}
+}
+
fnmain(){
+letv=vec![1,2,3,4,5];
+letthird: &i32=&v[2];
+println!("The third element is {}",third);
+
+matchv.get(2){
+Some(third)=>println!("The third element id {}",third);
+
+None=>println!("There is no third element");
+}
+}
+
structImportantExcerpt<'a>{
+part: &'astr,
+}
+
+fnmain(){
+letnovelString::from("Call me Ishmael. Some years ago...");
+
+// 下面一行first_sentence的生命周期开始
+letfirst_sentence=novel.split('.').next().expect("Could not found a '.'");
+
+// 下面一行i的生命周期开始
+leti=ImportantExcerpt{
+part: first_sentence
+};
+}
+
implGuess{
+pubfnnew(value: u32)-> Guess{
+ifvalue<1{
+panic("Guess value must be between 1 and 100, got {}.",value);
+}elseifvalue>100{
+panic("Guess value must be less than or equal to 100, got {}",value);
+}
+
+Guess{value}
+}
+}
+
+#[cfg(test)]
+modtest{
+usesuper::*;
+
+#[test]
+#[should_panic(expected = "Guess value must be less than or equal to 100")]
+fngreater_than_100(){
+Guess::new(200);
+}
+}
+
#[cfg(test)]
+modtests{
+#[test]
+
+fnit_works-> Result<(),String>{
+if2+2==4{
+Ok(())
+}else{
+Err(String::from("two plus two does not equal four"))
+}
+}
+}
+
[package]
+name="s43_minigrep_optmize"
+version="0.1.0"
+edition="2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[profile.dev]
+opt-level=0
+
+[profile.release]
+opt-level=3
+
//! # My Crate
+//!
+//! `my_crate` is a collection of utilities to make performing certain calculations more convenient
+
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```
+/// let args = 5;
+/// let answer = my_crate::add_one(args);
+///
+/// assert_eq!(6, anwser);
+/// ```dotnetcli
+pubfnadd_one(x: i32)-> i32{
+x+1
+}
+
//! # Art
+//!
+//! A library for modeling artistic concept.
+
+pubmodkinds{
+/// The primary colors according to the RYB color model.
+pubenumPrimaryColor{
+Red,
+Yellow,
+Blue,
+}
+
+/// The second colors according to RYB color model.
+pubenumSecondaryColor{
+Orange,
+Green,
+Purple,
+}
+}
+
+pubmodutils{
+usecrate::kinds::*;
+
+/// Combines two primary colors in equal amounts to crate
+/// a secondary color.
+pubfnmix(c1: PrimaryColor,c2: PrimaryColor)->SecondaryColor{
+SecondaryColor::Green
+}
+}
+
[package]
+name="s44_cargo"
+version="0.1.0"
+author=["kotlindev"]
+edition="2021"
+description="A Rust tutorials"
+license="MIT"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
leta=Rc::new(Cons(5,Rc::new(Cons(10,Rc::new(Nil)))));
+println!("counter after creating a = {}",Rc::strong_count(&a));
+
+letb=Cons(3,Rc::clone(&a));
+println!("counter after creating b = {}",Rc::strong_count(&a));
+
+{
+letc=Cons(3,Rc::clone(&a));
+println!("counter after creating c = {}",Rc::strong_count(&a));
+}
+
+println!(
+"counter after c goes out of scopes = {}",
+Rc::strong_count(&a)
+);
+
usestd::thread::{self,Thread};
+usestd::time::Duration;
+
+fnmain(){
+thread::spawn(||{
+foriin1..10{
+println!("hi number {} from the spawnd thread!",i);
+thread::sleep(Duration::from_millis(1));
+}
+});
+
+foriin1..5{
+println!("hi number {} from the main thread!",i);
+thread::sleep(Duration::from_millis(1));
+}
+}
+
usestd::thread::{self,Thread};
+usestd::time::Duration;
+
+fnmain(){
+lethandle=thread::spawn(||{
+foriin1..10{
+println!("hi number {} from the spawnd thread!",i);
+thread::sleep(Duration::from_millis(1));
+}
+});
+
+foriin1..5{
+println!("hi number {} from the main thread!",i);
+thread::sleep(Duration::from_millis(1));
+}
+
+handle.join().unwrap();
+}
+
matchp{
+// 要求y的值是0，x随意
+Point{x,y: 0}=>println("On the x axis at {}",x),
+// 要求x的值是0，y随意
+Point{x: 0,y}=>println("On the y axis at {}",y),
+// 如果前两个模式都无法匹配的话，将匹配最后一个
+Point{x,y}=>println("On neither axis: ({}, {})",x,y),
+}
+
enumMessage{
+Quit,
+Move{x: i32,y: i32},
+Write(String),
+ChangeColor(i32,i32,i32),
+}
+
+fnmain(){
+letmsg=Message::ChangeColor(0,160,255);
+
+matchmsg{
+Message::Quit=>{
+println!("The Quit variant has no data to destructure.")
+}
+Message::Move{x,y}=>{
+println!("Move in the x direction {} and in the y direction {}.",x,y)
+}
+Message::Write(text)=>println!("Text message: {}",text),
+Message::ChangeColor(r,g,b)=>{
+println!("change the color to red {}, green {}, and blue {}",r,g,b)
+}
+}
+}
+
enumColor{
+Rgb(i32,i32,i32),
+Hsv(i32,i32,i32),
+}
+
+enumMessage{
+Quit,
+Move{x: i32,y: i32},
+Write(String),
+ChangeColor(Color),
+}
+
+fnmain(){
+letmsg=Message::ChangeColor(Color::Hsv(0,160,255));
+
+matchmsg{
+Message::ChangeColor(Color::Rgb(r,g,b))=>{
+println!("change the color to red {}, green {}, and blue {}",r,g,b)
+}
+Message::ChangeColor(Color::Hsv(h,s,v))=>{
+println!("change the color to hue {}, saturation {}, and value {}",h,s,v)
+}
+_=>(),
+}
+}
+
enumMessage{
+Hello{id: i32},
+}
+
+fnmain(){
+letmsg{
+Message::Hello{
+id: id_variable@3..=7,
+}=>{
+println!("Found an id in range: {}",id_variable);
+}
+Message::Hello{
+id: 10..=12,
+}=>{
+println!("Found an id in another range");
+}
+Message::Hello{id}=>{
+println!("Found an other id: {}",id);
+}
+}
+}
+
extern关键字：简化创建和使用外部函数接口（FFI）的过程。外部函数接口（FFI，Foreign Function Interface），它允许一种编程语言定义函数，并让其他编程语言能调用这些函数。任何在extern块里声明的函数都是不安全的，因为其他语言并不会强制执行rust遵守的规则，而rust又无法对它们进行检查。所以在调用外部函数的过程中，如何保证程序安全的责任也落在了开发者身上。如下示例代码
+
// C 指明了外部函数使用的应用二进制接口（Application Binary Intreface），即ABI
+// ABI 是用于定义函数在汇编层面的调用方式
+extern"C"{
+// 想要调用的外部函数的名称和签名
+fnabs(input: i32)-> i32;
+}
+
+fnmain(){
+unsafe{
+println!("Absolute value of -3 according to C: {}",abs(-3));
+}
+}
+
完全限定语法的格式为：<Type as Trait>::function(receiver_if_method, next_arg, ...)，这种语法可以在任何调用函数或方法的地方使用，并且它允许忽略那些从上下文能推导出来的部分。但要记住的是，当rust无法区分我们调用哪个具体实现的时候，才需使用这种语法，因为这种语法写起来比较麻烦，不该轻易使用。如下示例代码
+
// ...
+
+fnmain(){
+// 调用本身的方法
+println!("A baby dog is called a {}",Dog::baby_name());
+// 调用实现Animal的方法
+println!("A baby dog is called a {}",<DogasAnimal>::baby_name());
+}
+
