Rust errors / Types and traits
Rust compiler error · checked with rustc 1.99.0
Rust error E0323: item `N` is an associated const, which doesn't match its trait `Foo`
What it meansAn associated const was implemented when another trait item was expected.
What rustc prints
error[E0323]: item `N` is an associated const, which doesn't match its trait `Foo`
--> main.rs:8:5
|
2 | type N;
| ------- item in trait
...
8 | const N : u32 = 0;
| ^^^^^^^^^^^^^^^^^^ does not match traitReal output of rustc 1.99.0 compiling the official example below (2021 edition). Your names and line numbers will differ; the first line is the part to match.
E0323Types and traits
Activein rustc 1.99.0
8related errors linked below
The compiler team's explanation
An associated const was implemented when another trait item was expected.
Erroneous code example:
trait Foo {
type N;
}
struct Bar;
impl Foo for Bar {
const N : u32 = 0;
// error: item `N` is an associated const, which doesn't match its
// trait `<Bar as Foo>`
}Please verify that the associated const wasn't misspelled and the correct trait was implemented. Example:
struct Bar;
trait Foo {
type N;
}
impl Foo for Bar {
type N = u32; // ok!
}Or:
struct Bar;
trait Foo {
const N : u32;
}
impl Foo for Bar {
const N : u32 = 0; // ok!
}From rustc --explain E0323 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
Related errors
- E0308mismatched types
- E0277the trait bound is not satisfied
- E0599no method named X found in the current scope
- E0433failed to resolve
- E0321cross-crate traits with a default impl, like `Send`, can only be implemented for a struct/enum type, not `&'static Foo`
- E0322explicit impls for the `Sized` trait are not permitted
- E0324item `N` is an associated method, which doesn't match its trait `Foo`
- E0325item `N` is an associated type, which doesn't match its trait `Foo`
Up next
Often hit nextE0308: mismatched typesA related error from the same family.Read it next →Did this answer your question?