文章目录
- [一、Generic structures泛型结构体](#一、Generic structures泛型结构体)
- [二、Generic Function泛型函数](#二、Generic Function泛型函数)
- 参考
一、Generic structures泛型结构体
泛型是一种编程语言的特性,它允许在代码中使用参数化类型,以便在不同地方使用
相同的代码逻辑处理多种数据类型,而无需为每种类型编写单独的代码!
作用:
1.提高代码的重用性
2.提高代码的可读性
3.提高代码的抽象度
1.泛型的应用类型
1.泛型定义结构体\枚举
2.泛型定义函数
3.泛型与特质
rust
#[derive(Debug)]
struct Point<T> {
x: T,
y: T,
}
#[derive(Debug)]
struct PointTwo<T, E> {
x: T,
y: E,
}
fn main() {
let c1 = Point { x: 1.0, y: 2.0 };
let c2 = Point { x: 'x', y: 'y' };
println!("c1 {:?} c2 {:?}", c1, c2);
let c = PointTwo { x: 1.0, y: 'z' };
println!("{:?}", c);
// Zero-Cost Abstraction
}
编译及运行:
bash
cargo run
Compiling ch1_generic_struct v0.1.0 (/home/wangji/installer/rust/project/ch23_generic_struct)
warning: fields `x` and `y` are never read
--> src/main.rs:3:5
|
2 | struct Point<T> {
| ----- fields in this struct
3 | x: T,
| ^
4 | y: T,
| ^
|
= note: `Point` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
= note: `#[warn(dead_code)]` on by default
warning: fields `x` and `y` are never read
--> src/main.rs:9:5
|
8 | struct PointTwo<T, E> {
| -------- fields in this struct
9 | x: T,
| ^
10 | y: E,
| ^
|
= note: `PointTwo` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
warning: `ch1_generic_struct` (bin "ch1_generic_struct") generated 2 warnings
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
Running `target/debug/ch1_generic_struct`
c1 Point { x: 1.0, y: 2.0 } c2 Point { x: 'x', y: 'y' }
PointTwo { x: 1.0, y: 'z' }
二、Generic Function泛型函数
在Rust中,泛型也可以用于函数,使得函数能够处理多种类型的参数,提高代码的重用性和灵活性
1.泛型与普通函数
2.泛型与结构体中的方法
rust
// 交换
fn swap<T>(a: T, b: T) -> (T, T) {
(b, a)
}
struct Point<T> {
x: T,
y: T,
}
impl<T> Point<T> {
// 构造函数
fn new(x: T, y: T) -> Self {
Point { x, y }
}
// 方法
fn get_coordinates(&self) -> (&T, &T) {
(&self.x, &self.y)
}
}
fn main() {
let result = swap::<f64>(0.1, 1.0);
let result: (f64, f64) = swap(0.1, 1.0);
println!("{:?}", result);
let str2 = swap("hh", "tt");
println!("str2.0 {} str2.1 {}", str2.0, str2.1);
let str2 = swap(str2.0, str2.1);
println!("str2.0 {} str2.1 {}", str2.0, str2.1);
let i32_point = Point::new(2, 3);
let f64_point = Point::new(2.0, 3.0);
let (x1, y1) = i32_point.get_coordinates();
let (x2, y2) = f64_point.get_coordinates();
println!("i32 point: x= {} y= {}", x1, y1);
println!("f64 point: x= {} y= {}", x2, y2);
// String 不要用&str
//最好使用:let string_point = Point::new("xxx".to_owned(), "yyyy".to_owned());
let string_point = Point::new("xxx", "yyyy");
println!("string point x = {} y = {}", string_point.x, string_point.y);
}
编译及运行
bash
cargo run
Compiling ch24_func v0.1.0 (/home/wangji/installer/rust/project/ch24_func)
warning: unused variable: `result`
--> src/main.rs:23:9
|
23 | let result = swap::<f64>(0.1, 1.0);
| ^^^^^^ help: if this is intentional, prefix it with an underscore: `_result`
|
= note: `#[warn(unused_variables)]` on by default
warning: `ch24_func` (bin "ch24_func") generated 1 warning
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.33s
Running `target/debug/ch24_func`
(1.0, 0.1)
str2.0 tt str2.1 hh
str2.0 hh str2.1 tt
i32 point: x= 2 y= 3
f64 point: x= 2 y= 3
string point x = xxx y = yyyy