| /// Many of our internal operations (e.g., unification) are an attempt | |
| /// to perform some operation which may not complete. | |
| pub type Fallible<T> = Result<T, NoSolution>; | |
| /// Indicates that the attempted operation has "no solution" -- i.e., | |
| /// cannot be performed. | |
| #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)] | |
| pub struct NoSolution; |