E0300: Interface not found
| Code | Category | Stability |
|---|---|---|
E0300 | Semantic | Permanent |
Explanation
A conformance assertion, refinement, or comptime parameter bound names an interface that cannot be resolved. Interface declarations follow ordinary module naming and visibility rules.
Likely cause
The interface name is misspelled, its module has not been imported, or the declaration is private. Declare the interface or use its accessible module-qualified name.
Examples
Unknown interface
Requires --preview interfaces.
struct Value is Missing {}
fn main() {}
Declare the interface
Requires --preview interfaces.
interface Marker { fn mark(borrow self); }
struct Value is Marker { fn mark(borrow self) {} }
fn main() {}