Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request #1620 from dtolnay/error
Export std error type so no_std data formats don't need a "std" feature
- Loading branch information
Showing
4 changed files
with
67 additions
and
2 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,48 @@ | ||
use lib::{Debug, Display}; | ||
|
||
/// Either a re-export of std::error::Error or a new identical trait, depending | ||
/// on whether Serde's "std" feature is enabled. | ||
/// | ||
/// Serde's error traits [`serde::ser::Error`] and [`serde::de::Error`] require | ||
/// [`std::error::Error`] as a supertrait, but only when Serde is built with | ||
/// "std" enabled. Data formats that don't care about no\_std support should | ||
/// generally provide their error types with a `std::error::Error` impl | ||
/// directly: | ||
/// | ||
/// ```edition2018 | ||
/// #[derive(Debug)] | ||
/// struct MySerError {...} | ||
/// | ||
/// impl serde::ser::Error for MySerError {...} | ||
/// | ||
/// impl std::fmt::Display for MySerError {...} | ||
/// | ||
/// // We don't support no_std! | ||
/// impl std::error::Error for MySerError {} | ||
/// ``` | ||
/// | ||
/// Data formats that *do* support no\_std may either have a "std" feature of | ||
/// their own: | ||
/// | ||
/// ```toml | ||
/// [features] | ||
/// std = ["serde/std"] | ||
/// ``` | ||
/// | ||
/// ```edition2018 | ||
/// #[cfg(feature = "std")] | ||
/// impl std::error::Error for MySerError {} | ||
/// ``` | ||
/// | ||
/// ... or else provide the std Error impl unconditionally via Serde's | ||
/// re-export: | ||
/// | ||
/// ```edition2018 | ||
/// impl serde::ser::StdError for MySerError {} | ||
/// ``` | ||
pub trait Error: Debug + Display { | ||
/// The underlying cause of this error, if any. | ||
fn source(&self) -> Option<&(Error + 'static)> { | ||
None | ||
} | ||
} |