src/test/ui/traits/coercion.rs

   1 // run-pass
   2 #![allow(dead_code)]
   3 #![allow(unused_mut)]
   4 #![allow(unused_variables)]
   5
   6 use std::io::{self, Write};
   7
   8 trait Trait {
   9     fn f(&self);
  10 }
  11
  12 #[derive(Copy, Clone)]
  13 struct Struct {
  14     x: isize,
  15     y: isize,
  16 }
  17
  18 impl Trait for Struct {
  19     fn f(&self) {
  20         println!("Hi!");
  21     }
  22 }
  23
  24 fn foo(mut a: Box<dyn Write>) {}
  25
  26 pub fn main() {
  27     let a = Struct { x: 1, y: 2 };
  28     let b: Box<dyn Trait> = Box::new(a);
  29     b.f();
  30     let c: &dyn Trait = &a;
  31     c.f();
  32
  33     let out = io::stdout();
  34     foo(Box::new(out));
  35 }