mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-27 09:14:20 +00:00
20 lines
345 B
Rust
20 lines
345 B
Rust
//@ run-pass
|
|
// Tests that unary structs can be mutably borrowed.
|
|
|
|
struct Empty;
|
|
|
|
trait T<U> {
|
|
fn next(&mut self) -> Option<U>;
|
|
}
|
|
impl T<isize> for Empty {
|
|
fn next(&mut self) -> Option<isize> { None }
|
|
}
|
|
|
|
fn do_something_with(a : &mut dyn T<isize>) {
|
|
println!("{:?}", a.next())
|
|
}
|
|
|
|
pub fn main() {
|
|
do_something_with(&mut Empty);
|
|
}
|