File: const-default-impl-non-const-specialized-impl.rs

package info (click to toggle)
rustc-web 1.78.0%2Bdfsg1-2~deb11u3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 1,245,360 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 (26 lines) | stat: -rw-r--r-- 505 bytes parent folder | download | duplicates (2) 
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
 
// Tests that specializing trait impls must be at least as const as the default impl.

#![feature(const_trait_impl, effects)]
#![feature(min_specialization)]

#[const_trait]
trait Value {
    fn value() -> u32;
}

impl<T> const Value for T {
    default fn value() -> u32 {
        0
    }
}

struct FortyTwo;

impl Value for FortyTwo { //~ ERROR cannot specialize on const impl with non-const impl
    fn value() -> u32 {
        println!("You can't do that (constly)");
        42
    }
}

fn main() {}