src/test/run-pass/supertrait-default-generics.rs

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // There is some other borrowck bug, so we make the stuff not mut.
  12
  13 // pretty-expanded FIXME #23616
  14
  15 use std::ops::Add;
  16
  17 trait Positioned<S> {
  18   fn SetX(&mut self, S);
  19   fn X(&self) -> S;
  20 }
  21
  22 trait Movable<S: Add<Output=S>>: Positioned<S> {
  23   fn translate(&mut self, dx: S) {
  24     let x = self.X() + dx;
  25     self.SetX(x);
  26   }
  27 }
  28
  29 struct Point<S> { x: S, y: S }
  30
  31 impl<S: Clone> Positioned<S> for Point<S> {
  32     fn SetX(&mut self, x: S) {
  33         self.x = x;
  34     }
  35     fn X(&self) -> S {
  36         self.x.clone()
  37     }
  38 }
  39
  40 impl<S: Clone + Add<Output=S>> Movable<S> for Point<S> {}
  41
  42 pub fn main() {
  43     let mut p = Point{ x: 1, y: 2};
  44     p.translate(3);
  45     assert_eq!(p.X(), 4);
  46 }