add zh/generics.md

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sunface 2022-03-04 11:00:35 +08:00
parent f359056cac
commit fe6d0b4183
4 changed files with 153 additions and 5 deletions

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@ -34,7 +34,7 @@ fn main() {
2. 🌟🌟 A function call with explicitly specified type parameters looks like: `fun::<A, B, ...>()`.
```rust,editable
// implement a generic function
// implement the generic function below
fn sum
fn main() {
@ -124,7 +124,7 @@ fn main() {
7. 🌟🌟
```rust,editable
// make the code work
// fix the errors to make the code work
struct Point<T> {
x: T,
y: T,

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- [match, matches! 和 if let](pattern-match/match-iflet.md)
- [模式](pattern-match/patterns.md)
- [方法和关联函数](method.md)
- [泛型和特征 todo](generics-traits/intro.md)
- [泛型和特征](generics-traits/intro.md)
- [泛型 Generics](generics-traits/generics.md)
- [特征 Traits](generics-traits/traits.md)
- [特征对象](generics-traits/trait-object.md)

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# Generics
# 泛型
### 函数
1. 🌟🌟🌟
```rust,editable
// 填空
struct A; // 具体的类型 `A`.
struct S(A); // 具体的类型 `S`.
struct SGen<T>(T); // 泛型 `SGen`.
fn reg_fn(_s: S) {}
fn gen_spec_t(_s: SGen<A>) {}
fn gen_spec_i32(_s: SGen<i32>) {}
fn generic<T>(_s: SGen<T>) {}
fn main() {
// 使用非泛型函数
reg_fn(__); // 具体的类型
gen_spec_t(__); // 隐式地指定类型参数 `A`.
gen_spec_i32(__); // 隐式地指定类型参数`i32`.
// 显式地指定类型参数 `char`
generic::<char>(__);
// 隐式地指定类型参数 `char`.
generic(__);
}
```
1. 🌟🌟
```rust,editable
// 实现下面的泛型函数 sum
fn sum
fn main() {
assert_eq!(5, sum(2i8, 3i8));
assert_eq!(50, sum(20, 30));
assert_eq!(2.46, sum(1.23, 1.23));
}
```
### 结构体和 `impl`
3. 🌟
```rust,editable
// 实现一个结构体 Point 让代码工作
fn main() {
let integer = Point { x: 5, y: 10 };
let float = Point { x: 1.0, y: 4.0 };
}
```
4. 🌟🌟
```rust,editable
// 修改以下结构体让代码工作
struct Point<T> {
x: T,
y: T,
}
fn main() {
// 不要修改这行代码!
let p = Point{x: 5, y : "hello".to_string()};
}
```
5. 🌟🌟
```rust,editable
// 为 Val 增加泛型参数,不要修改 `main` 中的代码
struct Val {
val: f64,
}
impl Val {
fn value(&self) -> &f64 {
&self.val
}
}
fn main() {
let x = Val{ val: 3.0 };
let y = Val{ val: "hello".to_string()};
println!("{}, {}", x.value(), y.value());
}
```
### 方法
6. 🌟🌟🌟
```rust,editable
struct Point<T, U> {
x: T,
y: U,
}
impl<T, U> Point<T, U> {
// 实现 mixup不要修改其它代码
fn mixup
}
fn main() {
let p1 = Point { x: 5, y: 10 };
let p2 = Point { x: "Hello", y: '中'};
let p3 = p1.mixup(p2);
assert_eq!(p3.x, 5);
assert_eq!(p3.y, '中');
}
```
7. 🌟🌟
```rust,editable
// 修复错误,让代码工作
struct Point<T> {
x: T,
y: T,
}
impl Point<f32> {
fn distance_from_origin(&self) -> f32 {
(self.x.powi(2) + self.y.powi(2)).sqrt()
}
}
fn main() {
let p = Point{x: 5, y: 10};
println!("{}",p.distance_from_origin())
}
```
> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下)

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@ -255,4 +255,7 @@ fn main() {
## Practice
@todo
@todo
> 你可以在[这里](https://github.com/sunface/rust-by-practice)找到答案(在 solutions 路径下)