unknown trait

Why this fires¶

An impl <Trait> for <Type> names a trait that doesn't exist — neither a trait declared in the program nor one of the known standard traits (Iterator, Eq, Ord, Default, ...). Usually a typo.

trait Iterable { fn next(self) -> int }

struct V {}
impl Iterabe for V {
//   ^^^^^^^ error[TE302]: unknown trait 'Iterabe' in `impl ... for V`. Did you mean 'Iterable'?
    fn next(self) -> int { return 0 }
}

Fix it¶

Trust the "did you mean?" suggestion and fix the spelling:

impl Iterable for V {
    fn next(self) -> int { return 0 }
}

See also¶

• TE822 — the same "unknown trait" check for a generic parameter's trait bound.
• TE825 — an impl is missing one of the trait's required methods.
• /docs/data-structures#traits — declaring and implementing traits.