remi.rs

struct Vec { x: float, y: float }

trait VecRhs {
    fn add_to_Vec(&self, lhs: &Vec) -> Vec;
}

impl<R: VecRhs> Add<R, Vec> for Vec {
    fn add(&self, rhs: &R) -> Vec {
         rhs.add_to_Vec(self)
    }
}

impl VecRhs for Vec {
    fn add_to_Vec(&self, lhs: &Vec) -> Vec {
        Vec { x:lhs.x+self.x, y:lhs.y+self.y }
    }
}

impl VecRhs for float {
    fn add_to_Vec(&self, lhs: &Vec) -> Vec {
        Vec { x:lhs.x+*self, y:lhs.y+*self }
    }
}

fn main() {
    let mut foo = Vec { x: 2.0, y: 4.0 };
    foo += 2.0;
    println(fmt!("%?", foo));
    foo += Vec { x: 1.0, y: 3.0 };
    println(fmt!("%?", foo));
}