tuwunel_core/utils/result/
not_found.rs

1use super::Result;
2use crate::Error;
3
4/// Classifies and adapts results carrying the crate's not-found error family.
5///
6/// Successful results and unrelated errors are not classified as missing, and
7/// only a not-found error converts to an absent value. Classification
8/// delegates to `Error::is_not_found`.
9pub trait NotFound<T> {
10	/// Reports whether the result contains a not-found error.
11	///
12	/// An `Ok` value always returns false. Other error variants also return
13	/// false without changing the result.
14	#[must_use]
15	fn is_not_found(&self) -> bool;
16
17	/// Converts a not-found error into an absent value.
18	///
19	/// An `Ok` value is wrapped in `Some` and a not-found error becomes
20	/// `Ok(None)`, so a caller distinguishes an absent value from a failed
21	/// operation. Every other error is returned unchanged.
22	fn optional(self) -> Result<Option<T>>;
23}
24
25impl<T> NotFound<T> for Result<T, Error> {
26	#[inline]
27	fn is_not_found(&self) -> bool { self.as_ref().is_err_and(Error::is_not_found) }
28
29	#[inline]
30	fn optional(self) -> Result<Option<T>> {
31		self.map(Some)
32			.or_else(|error| error.is_not_found().then_some(None).ok_or(error))
33	}
34}
tuwunel_core/utils/result/not_found.rs

tuwunel_core/utils/result/
not_found.rs
