Trait otter_api_tests::Error
1.0.0 · source · [−]pub trait Error: Debug + Display {
fn source(&self) -> Option<&(dyn Error + 'static)> { ... }
fn backtrace(&self) -> Option<&Backtrace> { ... }
fn description(&self) -> &str { ... }
fn cause(&self) -> Option<&dyn Error> { ... }
}
Expand description
Error
is a trait representing the basic expectations for error values,
i.e., values of type E
in Result<T, E>
.
Errors must describe themselves through the Display
and Debug
traits. Error messages are typically concise lowercase sentences without
trailing punctuation:
let err = "NaN".parse::<u32>().unwrap_err();
assert_eq!(err.to_string(), "invalid digit found in string");
Errors may provide cause chain information. Error::source()
is generally
used when errors cross “abstraction boundaries”. If one module must report
an error that is caused by an error from a lower-level module, it can allow
accessing that error via Error::source()
. This makes it possible for the
high-level module to provide its own errors while also revealing some of the
implementation for debugging via source
chains.
Provided methods
The lower-level source of this error, if any.
Examples
use std::error::Error;
use std::fmt;
#[derive(Debug)]
struct SuperError {
source: SuperErrorSideKick,
}
impl fmt::Display for SuperError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "SuperError is here!")
}
}
impl Error for SuperError {
fn source(&self) -> Option<&(dyn Error + 'static)> {
Some(&self.source)
}
}
#[derive(Debug)]
struct SuperErrorSideKick;
impl fmt::Display for SuperErrorSideKick {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "SuperErrorSideKick is here!")
}
}
impl Error for SuperErrorSideKick {}
fn get_super_error() -> Result<(), SuperError> {
Err(SuperError { source: SuperErrorSideKick })
}
fn main() {
match get_super_error() {
Err(e) => {
println!("Error: {e}");
println!("Caused by: {}", e.source().unwrap());
}
_ => println!("No error"),
}
}
backtrace
)Returns a stack backtrace, if available, of where this error occurred.
This function allows inspecting the location, in code, of where an error
happened. The returned Backtrace
contains information about the stack
trace of the OS thread of execution of where the error originated from.
Note that not all errors contain a Backtrace
. Also note that a
Backtrace
may actually be empty. For more information consult the
Backtrace
type itself.
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
if let Err(e) = "xc".parse::<u32>() {
// Print `e` itself, no need for description().
eprintln!("Error: {e}");
}
Implementations
sourceimpl dyn Error + 'static
impl dyn Error + 'static
1.3.0 · sourcepub fn is<T>(&self) -> bool where
T: 'static + Error,
pub fn is<T>(&self) -> bool where
T: 'static + Error,
Returns true
if the inner type is the same as T
.
1.3.0 · sourcepub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
Returns some reference to the inner value if it is of type T
, or
None
if it isn’t.
1.3.0 · sourcepub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
Returns some mutable reference to the inner value if it is of type T
, or
None
if it isn’t.
sourceimpl dyn Error + Send + 'static
impl dyn Error + Send + 'static
1.3.0 · sourcepub fn is<T>(&self) -> bool where
T: 'static + Error,
pub fn is<T>(&self) -> bool where
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
1.3.0 · sourcepub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
1.3.0 · sourcepub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
sourceimpl dyn Error + Send + Sync + 'static
impl dyn Error + Send + Sync + 'static
1.3.0 · sourcepub fn is<T>(&self) -> bool where
T: 'static + Error,
pub fn is<T>(&self) -> bool where
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
1.3.0 · sourcepub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
1.3.0 · sourcepub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
sourceimpl dyn Error + 'static
impl dyn Error + 'static
1.3.0 · sourcepub fn downcast<T>(
self: Box<dyn Error + 'static, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static, Global>> where
T: 'static + Error,
pub fn downcast<T>(
self: Box<dyn Error + 'static, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static, Global>> where
T: 'static + Error,
Attempts to downcast the box to a concrete type.
sourcepub fn chain(&self) -> Chain<'_>ⓘNotable traits for Chain<'a>impl<'a> Iterator for Chain<'a> type Item = &'a (dyn Error + 'static);
🔬 This is a nightly-only experimental API. (error_iter
)
pub fn chain(&self) -> Chain<'_>ⓘNotable traits for Chain<'a>impl<'a> Iterator for Chain<'a> type Item = &'a (dyn Error + 'static);
error_iter
)Returns an iterator starting with the current error and continuing with
recursively calling Error::source
.
If you want to omit the current error and only use its sources,
use skip(1)
.
Examples
#![feature(error_iter)]
use std::error::Error;
use std::fmt;
#[derive(Debug)]
struct A;
#[derive(Debug)]
struct B(Option<Box<dyn Error + 'static>>);
impl fmt::Display for A {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "A")
}
}
impl fmt::Display for B {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "B")
}
}
impl Error for A {}
impl Error for B {
fn source(&self) -> Option<&(dyn Error + 'static)> {
self.0.as_ref().map(|e| e.as_ref())
}
}
let b = B(Some(Box::new(A)));
// let err : Box<Error> = b.into(); // or
let err = &b as &(dyn Error);
let mut iter = err.chain();
assert_eq!("B".to_string(), iter.next().unwrap().to_string());
assert_eq!("A".to_string(), iter.next().unwrap().to_string());
assert!(iter.next().is_none());
assert!(iter.next().is_none());
Trait Implementations
Implementations on Foreign Types
sourceimpl Error for NulError
impl Error for NulError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl Error for FromUtf8Error
impl Error for FromUtf8Error
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for ExitStatusError
sourceimpl<T> Error for PoisonError<T>
impl<T> Error for PoisonError<T>
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for TryReserveError
sourceimpl Error for FromUtf16Error
impl Error for FromUtf16Error
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
1.4.0 · sourceimpl Error for AddrParseError
impl Error for AddrParseError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
1.51.0 · sourceimpl<'a, T> Error for &'a T where
T: Error + ?Sized,
impl<'a, T> Error for &'a T where
T: Error + ?Sized,
sourceimpl<T> Error for TryLockError<T>
impl<T> Error for TryLockError<T>
1.7.0 · sourceimpl Error for IntoStringError
impl Error for IntoStringError
1.7.0 · sourceimpl Error for StripPrefixError
impl Error for StripPrefixError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for !
impl Error for FromVecWithNulError
1.17.0 · sourceimpl Error for FromBytesWithNulError
impl Error for FromBytesWithNulError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for SenderError
impl Error for Broken
impl Error for InvalidOutputSize
sourceimpl Error for OutOfRangeError
impl Error for OutOfRangeError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl Error for ParseError
impl Error for ParseError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for CaseFoldError
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for UnicodeWordError
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
impl Error for ParseColorError
impl Error for ParseColorError
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for DifferentVariant
impl Error for ParseFromDescription
impl Error for ConversionRange
impl Error for IndeterminateOffset
impl Error for ComponentRange
impl Error for InvalidVariant
impl Error for InvalidFormatDescription
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl<T> Error for TrySendError<T> where
T: Any,
impl<T> Error for TrySendError<T> where
T: Any,
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl<T> Error for SendError<T> where
T: Any,
impl<T> Error for SendError<T> where
T: Any,
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
impl<E> Error for Compat<E> where
E: Display + Debug,
impl<E> Error for Compat<E> where
E: Display + Debug,
fn description(&self) -> &'static str
fn description(&self) -> &'static str
use the Display impl or to_string()
impl Error for BernoulliError
impl Error for WeightedError
impl Error for Error
sourceimpl<'i, R> Error for Error<R> where
R: RuleType,
impl<'i, R> Error for Error<R> where
R: RuleType,
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for GlobError
impl Error for GlobError
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for FromUtf8Error
impl Error for FromUtf8Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Utf8Error
impl Error for Utf8Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for CompressError
impl Error for DecompressError
impl Error for Error
sourceimpl Error for ParseError
impl Error for ParseError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for ParseError
impl Error for Errors
impl Error for Error
sourceimpl Error for Error
impl Error for Error
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl Error for StreamError
impl Error for StreamError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for UnsupportedError
impl Error for LimitError
sourceimpl Error for ParseRatioError
impl Error for ParseRatioError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl<T> Error for TryFromBigIntError<T> where
T: Debug,
impl<T> Error for TryFromBigIntError<T> where
T: Debug,
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl Error for ParseBigIntError
impl Error for ParseBigIntError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for DecodingError
impl Error for DecodingError
impl Error for EncodingError
impl Error for EncodingError
sourceimpl Error for Error
impl Error for Error
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for InvalidUriParts
impl Error for InvalidMethod
impl Error for InvalidUri
impl Error for ToStrError
impl Error for InvalidHeaderValue
impl Error for InvalidStatusCode
impl Error for InvalidHeaderName
impl<T, E> Error for TryChunksError<T, E> where
E: Debug + Display,
impl<T> Error for ReuniteError<T> where
T: Any,
impl Error for Aborted
impl Error for SpawnError
impl Error for TryRecvError
impl Error for Error
impl Error for TryCurrentError
impl Error for RecvError
impl Error for TryAcquireError
impl Error for TryLockError
impl<T> Error for SendError<T> where
T: Debug,
impl Error for ReuniteError
impl<T> Error for SetError<T> where
T: Debug,
impl Error for RecvError
impl<T> Error for TrySendError<T> where
T: Debug,
impl Error for TryRecvError
impl Error for ReuniteError
impl<T> Error for SendError<T> where
T: Debug,
impl Error for AcquireError
impl<T> Error for SendTimeoutError<T> where
T: Debug,
impl Error for JoinError
impl Error for Elapsed
impl Error for TryRecvError
impl<T> Error for SendError<T> where
T: Debug,
impl Error for RecvError
impl Error for LinesCodecError
impl Error for AnyDelimiterCodecError
impl Error for LengthDelimitedCodecError
impl Error for InvalidNameError
impl Error for TryRecvError
impl Error for SendError
impl Error for Canceled
impl<T> Error for TrySendError<T> where
T: Any,
impl Error for ParseLevelFilterError
impl Error for ParseLevelError
impl Error for SetGlobalDefaultError
impl Error for Error
impl Error for LinesCodecError
impl Error for AnyDelimiterCodecError
impl Error for LengthDelimitedCodecError
impl<T> Error for PollSendError<T> where
T: Debug,
impl Error for Error
impl Error for Error
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
sourceimpl<S> Error for HandshakeError<S> where
S: Any + Debug,
impl<S> Error for HandshakeError<S> where
S: Any + Debug,
impl Error for Error
impl Error for X509VerifyResult
impl Error for ErrorStack
sourceimpl<S> Error for HandshakeError<S> where
S: Debug,
impl<S> Error for HandshakeError<S> where
S: Debug,
sourceimpl Error for FromStrError
impl Error for FromStrError
sourcefn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
fn cause(&self) -> Option<&dyn Error>
👎 Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
fn cause(&self) -> Option<&dyn Error>
replaced by Error::source, which can support downcasting
The lower-level cause of this error, in the case of a Utf8
error.
fn source(&self) -> Option<&(dyn Error + 'static)>
fn source(&self) -> Option<&(dyn Error + 'static)>
The lower-level source of this error, in the case of a Utf8
error.
fn description(&self) -> &str
fn description(&self) -> &str
use the Display impl or to_string()
impl Error for PrefixLenError
impl Error for AddrParseError
Implementors
impl Error for LoadError
impl Error for AccountsSaveError
impl Error for ApiPieceOpError
impl Error for Fatal
impl Error for Inapplicable
impl Error for InternalError
impl Error for InvalidScopedName
impl Error for LibraryLoadError
impl Error for MgmtChannelReadError
impl Error for MgmtChannelWriteError
impl Error for PieceOpErrorPartiallyProcessed
impl Error for SVGProcessingError
impl Error for SpecError
impl Error for VarError
impl Error for FlexiLoggerError
impl Error for DecodeError
impl Error for RoundingError
impl Error for Errno
impl Error for otter_api_tests::imports::regex::Error
impl Error for otter_api_tests::imports::rmp_serde::decode::Error
impl Error for otter_api_tests::imports::rmp_serde::encode::Error
impl Error for otter_api_tests::imports::toml::ser::Error
impl Error for RecvTimeoutError
impl Error for otter_api_tests::mpsc::TryRecvError
impl Error for Infallible
impl Error for MgmtError
impl Error for SubstErrorKind
impl Error for ZipError
impl Error for KeyError
impl Error for otter_api_tests::shapelib::toml_de::Error
impl Error for Void
impl Error for LogicError
impl Error for RangeImpossible
impl Error for AuthorisationError
impl Error for NotBundle
impl Error for JoinPathsError
impl Error for otter_api_tests::fmt::Error
impl Error for PosCFromIteratorError
impl Error for otter_api_tests::imports::chrono::ParseError
impl Error for InvalidBufferSize
impl Error for InvalidLength
impl Error for otter_api_tests::imports::digest::InvalidOutputSize
impl Error for MacError
impl Error for otter_api_tests::imports::glob::GlobError
impl Error for PatternError
impl Error for AllocError
impl Error for LayoutError
impl Error for TryFromSliceError
impl Error for BorrowError
impl Error for BorrowMutError
impl Error for CharTryFromError
impl Error for DecodeUtf16Error
impl Error for ParseCharError
impl Error for TryFromCharError
impl Error for ParseFloatError
impl Error for ParseIntError
impl Error for otter_api_tests::imports::log::ParseLevelError
impl Error for SetLoggerError
impl Error for ClearEnvError
impl Error for FloatIsNan
impl Error for otter_api_tests::imports::otter_base::imports::serde::de::value::Error
impl Error for otter_api_tests::imports::tera::Error
impl Error for otter_api_tests::imports::toml::de::Error
impl Error for DatetimeParseError
impl Error for otter_api_tests::io::Error
impl Error for WriterPanicked
impl Error for otter_api_tests::mpsc::RecvError
impl Error for otter_api_tests::serde_json::Error
impl Error for AuthKeysManipError
impl Error for CoordinateOverflow
impl Error for SubstError
impl Error for TryFromIntError
impl Error for ParseBoolError
impl Error for otter_api_tests::str::Utf8Error
impl Error for AccountNotFound
impl Error for BadAssetUrlToken
impl Error for otter_api_tests::ExitStatusError
impl Error for FooParseError
impl Error for GameBeingDestroyed
impl Error for InternalLogicError
impl Error for InvalidAbbrevPresentationLayout
impl Error for PlayerNotFound
impl Error for TokenDeliveryError
impl Error for UnsupportedColourSpec
impl Error for PathPersistError
impl Error for PersistError
impl Error for AccessError
impl Error for FromFloatSecsError
impl Error for SystemTimeError
impl Error for Overflow
impl Error for otter_api_tests::zcoord::ParseError
impl Error for TotallyUnboundedRange
impl Error for InvalidPassword
impl<'a, K, V> Error for otter_api_tests::btree_map::OccupiedError<'a, K, V> where
K: Debug + Ord,
V: Debug,
impl<'a, K, V> Error for otter_api_tests::hash_map::OccupiedError<'a, K, V> where
K: Debug,
V: Debug,
impl<E> Error for ParseNotNanError<E> where
E: 'static + Debug + Error,
impl<I> Error for ExactlyOneError<I> where
I: Iterator + Debug,
<I as Iterator>::Item: Debug,
impl<L, R> Error for Either<L, R> where
L: Error,
R: Error,
Either
implements Error
if both L
and R
implement it.
impl<T> Error for otter_api_tests::mpsc::TrySendError<T> where
T: Send,
impl<T> Error for CapacityError<T> where
T: Any,
Requires features="std"
.