Struct Error 

pub struct Error<E> { /* private fields */ }

An error container.

Error<E> is a lightweight handle to an error that can be cheaply cloned. It is Send and Sync when E is. It preserves the original error along with associated context such as the location where it occurred, the responsible service, a tag, a backtrace, and extension data.

Implementations

impl<E> Error<E>

pub fn new<T>(error: T, service: &'static str) -> Self

where E: From<T>,

Creates an error container associated with a service.

Captures the caller location and associates the error with a service.

pub fn from_err<T>(error: T) -> Self

where E: From<T>,

Creates an error container without service attribution.

Captures the caller location.

pub fn forward<U, F>(self, f: F) -> Error<U>

where F: FnOnce(Error<E>) -> U,

Transforms this error into another error type.

The closure receives the whole Error<E> container. Preserves tag, service, backtrace, and extension data.

pub fn debug(&self) -> impl Debug

where E: Debug,

Returns a debug view of the error.

pub fn get_item<T: 'static>(&self) -> Option<&T>

Returns a reference to a previously stored value of type T from this error.

This can be used to access additional contextual data attached to the error.

impl<E: Clone> Error<E>

pub fn with_tag<T: Into<Bytes>>(self, tag: T) -> Self

Sets a user-defined tag on this error.

Returns the updated error.

pub fn with_service(self, name: &'static str) -> Self

Sets the service responsible for this error.

Returns the updated error.

pub fn map<U, F>(self, f: F) -> Error<U>

where F: FnOnce(E) -> U,

Maps the inner error into a new error type using the provided closure.

Preserves tag, service, backtrace, and extension data.

pub fn map_err<U>(self) -> Error<U>

where U: From<E>,

Converts the inner error into a new error type via U: From<E>.

Preserves tag, service, backtrace, and extension data.

pub fn try_map<T, U, F>(self, f: F) -> Result<T, Error<U>>

where F: FnOnce(E) -> Result<T, U>,

Tries to map the inner error into a value or another error type.

On error, preserves tag, service, backtrace, and extension data.

pub fn into_error(self) -> E

Consumes this error and returns the inner error value.

pub fn with_item<T: Sync + Send + 'static>(self, val: T) -> Self

Attaches a typed value to this Error.

This value can be retrieved later using get_item.

Trait Implementations

impl<E: ErrorDiagnostic> AsError for Error<E>

type Target = E

Diagnostic error type.

fn as_diag(&self) -> &E

Returns the diagnostic error.

impl<E> Clone for Error<E>

fn clone(&self) -> Error<E>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<E: Debug> Debug for Error<E>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<E> Deref for Error<E>

type Target = E

The resulting type after dereferencing.

fn deref(&self) -> &E

Dereferences the value.

impl<E: Display> Display for Error<E>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<E> Eq for Error<E>

where E: Eq,

impl<E: Error + 'static> Error for Error<E>

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl<E: ErrorDiagnostic> ErrorDiagnostic for Error<E>

fn signature(&self) -> &'static str

Returns a stable identifier for the specific error classification.

fn tag(&self) -> Option<&Bytes>

Returns an optional tag associated with this error.

fn service(&self) -> Option<&'static str>

Returns the name of the responsible service, if applicable.

fn backtrace(&self) -> Option<&Backtrace>

Returns a backtrace for debugging purposes, if available.

impl<E> From<&Error<E>> for Failure

where E: ErrorDiagnostic,

fn from(err: &Error<E>) -> Self

Converts to this type from the input type.

impl<E> From<E> for Error<E>

fn from(error: E) -> Self

Converts to this type from the input type.

impl<E> From<Error<E>> for Failure

where E: ErrorDiagnostic,

fn from(err: Error<E>) -> Self

Converts to this type from the input type.

impl<E> PartialEq for Error<E>

where E: PartialEq,

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<E> PartialEq<E> for Error<E>

where E: PartialEq,

fn eq(&self, other: &E) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<E: Retryable> Retryable for Error<E>

fn is_retryable(&self) -> bool

Returns true if the failed operation can be retried.