auto-delegate

支持 no_std

此库是在没有 std 包的情况下创建的。

描述

自动委派允许您自动实现特质并将它们的处理委派给子。

用法

结构体

将 'delegate' 属性赋予要委派的特质，将 'Delegate' 赋予请求委派的结构体

示例1

use auto_delegate::{Delegate, delegate};

#[delegate]
trait Calc {
    fn calc(&self, x1: usize, x2: usize) -> usize;
}

#[derive(Default)]
struct CalcAdd;

impl Calc for CalcAdd {
    fn calc(&self, x1: usize, x2: usize) -> usize {
        x1 + x2
    }
}

#[derive(Delegate, Default)]
struct Parent {
    #[to(Calc)]
    child: CalcAdd
}


fn main() {
    let parent = Parent::default();

    assert_eq!(parent.calc(2, 3), 5);
}

示例2：多个特质量和字段

use auto_delegate::*;

#[delegate]
trait Calc {
    fn calc(&self, x1: usize, x2: usize) -> usize;
}


#[derive(Default)]
struct CalcAdd;


impl Calc for CalcAdd {
    fn calc(&self, x1: usize, x2: usize) -> usize {
        x1 + x2
    }
}


#[delegate]
trait Movable {
    fn move_to(&mut self, pos: (usize, usize));

    fn pos(&self) -> (usize, usize);
}


#[delegate]
trait Resizable {
    fn resize(&mut self, width: usize, height: usize);

    fn size(&self) -> (usize, usize);
}


#[derive(Default)]
struct Transform2D {
    pos: (usize, usize),
    width: usize,
    height: usize
}


impl Movable for Transform2D {
    fn move_to(&mut self, pos: (usize, usize)) {
        self.pos = pos;
    }

    fn pos(&self) -> (usize, usize) {
        self.pos
    }
}


impl Resizable for Transform2D {
    fn resize(&mut self, width: usize, height: usize) {
        self.width = width;
        self.height = height;
    }

    fn size(&self) -> (usize, usize) {
        (self.width, self.height)
    }
}


#[derive(Default, Delegate)]
struct Parent<T: Default + Calc> {
    #[to(Movable, Resizable)]
    transform: Transform2D,

    #[to(Calc)]
    calculator: T
}


fn main() {
    let mut parent = Parent::<CalcAdd>::default();

    assert_eq!(parent.calc(3, 2), 5);

    parent.move_to((10, 11));
    assert_eq!(parent.pos(), (10, 11));

    parent.resize(100, 120);
    assert_eq!(parent.size(), (100, 120));
}

枚举

类似于结构体，枚举可以使用 'Delegate' 进行委派。

示例

use auto_delegate::{delegate, Delegate};

#[delegate]
trait Calc {
    fn calc(&self, x1: usize, x2: usize) -> usize;
}

#[derive(Default)]
struct CalcAdd;

impl Calc for CalcAdd {
    fn calc(&self, x1: usize, x2: usize) -> usize {
        x1 + x2
    }
}

#[derive(Default)]
struct CalcSub;

impl Calc for CalcSub {
    fn calc(&self, x1: usize, x2: usize) -> usize {
        x1 - x2
    }
}


#[derive(Delegate)]
#[to(Calc)]
enum EnumCalc {
    Add(CalcAdd),
    Sub(CalcSub),
}


fn main() {
    let c = EnumCalc::Add(CalcAdd::default());
    assert_eq!(c.calc(3, 5), 8);


    let c = EnumCalc::Sub(CalcSub::default());
    assert_eq!(c.calc(3, 2), 1);
}

待办事项

• 支持自接收器(v0.0.8)
• 支持无接收器的方法(v0.1.0)
• 支持返回 impl 类型的特质方法。