An associated constant whose name does not match any of the associated constants in the trait was used when implementing the trait.
Erroneous code example:
trait Foo {}
impl Foo for i32 {
const BAR: bool = true;
}Trait implementations can only implement associated constants that are members of the trait in question.
The solution to this problem is to remove the extraneous associated constant:
trait Foo {}
impl Foo for i32 {}