File: coherence-impl-trait-for-trait.rs

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb12u3
  • links: PTS, VCS
  • area: main
  • in suites: bookworm
  • size: 1,245,420 kB
  • sloc: xml: 147,985; javascript: 18,022; sh: 11,083; python: 10,265; ansic: 6,172; cpp: 5,023; asm: 4,390; makefile: 4,269
file content (20 lines) | stat: -rw-r--r-- 485 bytes parent folder | download | duplicates (16)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
// Test that we give suitable error messages when the user attempts to
// impl a trait `Trait` for its own object type.

trait Foo { fn dummy(&self) { } }
trait Bar: Foo { }
trait Baz: Bar { }

// Supertraits of Baz are not legal:
impl Foo for dyn Baz { }
//~^ ERROR E0371
impl Bar for dyn Baz { }
//~^ ERROR E0371
impl Baz for dyn Baz { }
//~^ ERROR E0371

// But other random traits are:
trait Other { }
impl Other for dyn Baz { } // OK, Other not a supertrait of Baz

fn main() { }