29 lines
591 B
Rust
29 lines
591 B
Rust
|
// run-pass
|
||
|
|
// Tests for RFC 1268: we allow overlapping impls of marker traits,
|
||
|
|
// that is, traits without items. In this case, a type `T` is
|
||
|
|
// `MyMarker` if it is either `Debug` or `Display`.
|
||
|
|
|
||
|
|
#![feature(marker_trait_attr)]
|
||
|
|
#![feature(negative_impls)]
|
||
|
|
|
||
|
|
use std::fmt::{Debug, Display};
|
||
|
|
|
||
|
|
#[marker]
|
||
|
|
trait MyMarker {}
|
||
|
|
|
||
|
|
impl<T: Debug> MyMarker for T {}
|
||
|
|
impl<T: Display> MyMarker for T {}
|
||
|
|
|
||
|
|
fn foo<T: MyMarker>(t: T) -> T {
|
||
|
|
t
|
||
|
|
}
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
// Debug && Display:
|
||
|
|
assert_eq!(1, foo(1));
|
||
|
|
assert_eq!(2.0, foo(2.0));
|
||
|
|
|
||
|
|
// Debug && !Display:
|
||
|
|
assert_eq!(vec![1], foo(vec![1]));
|
||
|
|
}
|