Error code E0379

A trait method was declared const.

Erroneous code example:

#![allow(unused)]
fn main() {
trait Foo {
    const fn bar() -> u32; // error!
}

impl Foo for () {
    const fn bar() -> u32 { 0 } // error!
}
}
ⓘ

Trait methods cannot be declared const by design. For more information, see RFC 911.