rust/tests/ui/objects-coerce-freeze-borro...

41 lines
657 B
Rust

//@ run-pass
// Test that we can coerce an `@Object` to an `&Object`
trait Foo {
fn foo(&self) -> usize;
fn bar(&mut self) -> usize;
}
impl Foo for usize {
fn foo(&self) -> usize {
*self
}
fn bar(&mut self) -> usize {
*self += 1;
*self
}
}
fn do_it_mut(obj: &mut dyn Foo) {
let x = obj.bar();
let y = obj.foo();
assert_eq!(x, y);
do_it_imm(obj, y);
}
fn do_it_imm(obj: &dyn Foo, v: usize) {
let y = obj.foo();
assert_eq!(v, y);
}
pub fn main() {
let mut x: usize = 22;
let obj = &mut x as &mut dyn Foo;
do_it_mut(obj);
do_it_imm(obj, 23);
do_it_mut(obj);
}