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));
}