File: overlap-permitted-for-annotated-marker-traits.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, sid, trixie
  • size: 893,396 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; perl: 29; lisp: 29; ruby: 19; sql: 11
file content (27 lines) | stat: -rw-r--r-- 565 bytes parent folder | download | duplicates (6)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
//@ run-pass
// Tests for RFC 1268: we allow overlapping impls of marker traits,
// that is, traits with #[marker]. In this case, a type `T` is
// `MyMarker` if it is either `Debug` or `Display`.

#![feature(marker_trait_attr)]

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]));
}