Trait std::error::Error 1.0.0
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[src]
pub trait Error: Debug + Display {
fn description(&self) -> &str;
fn cause(&self) -> Option<&Error> { ... }
}Base functionality for all errors in Rust.
Required Methods
fn description(&self) -> &str
A short description of the error.
The description should only be used for a simple message.
It should not contain newlines or sentence-ending punctuation,
to facilitate embedding in larger user-facing strings.
For showing formatted error messages with more information see
Display.
Examples
use std::error::Error; match "xc".parse::<u32>() { Err(e) => { println!("Error: {}", e.description()); } _ => println!("No error"), }Run
Provided Methods
fn cause(&self) -> Option<&Error>
The lower-level cause of this error, if any.
Examples
use std::error::Error; use std::fmt; #[derive(Debug)] struct SuperError { side: 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 description(&self) -> &str { "I'm the superhero of errors" } fn cause(&self) -> Option<&Error> { Some(&self.side) } } #[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 description(&self) -> &str { "I'm SuperError side kick" } } fn get_super_error() -> Result<(), SuperError> { Err(SuperError { side: SuperErrorSideKick }) } fn main() { match get_super_error() { Err(e) => { println!("Error: {}", e.description()); println!("Caused by: {}", e.cause().unwrap()); } _ => println!("No error"), } }Run
Methods
impl Error + 'static[src]
fn is<T: Error + 'static>(&self) -> bool1.3.0
Returns true if the boxed type is the same as T
fn downcast_ref<T: Error + 'static>(&self) -> Option<&T>1.3.0
Returns some reference to the boxed value if it is of type T, or
None if it isn't.
fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T>1.3.0
Returns some mutable reference to the boxed value if it is of type T, or
None if it isn't.
impl Error + Send + 'static[src]
fn is<T: Error + 'static>(&self) -> bool1.3.0
Forwards to the method defined on the type Any.
fn downcast_ref<T: Error + 'static>(&self) -> Option<&T>1.3.0
Forwards to the method defined on the type Any.
fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T>1.3.0
Forwards to the method defined on the type Any.
impl Error + Send + Sync + 'static[src]
fn is<T: Error + 'static>(&self) -> bool1.3.0
Forwards to the method defined on the type Any.
fn downcast_ref<T: Error + 'static>(&self) -> Option<&T>1.3.0
Forwards to the method defined on the type Any.
fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T>1.3.0
Forwards to the method defined on the type Any.
impl Error[src]
fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Error>>1.3.0
Attempt to downcast the box to a concrete type.
impl Error + Send[src]
fn downcast<T: Error + 'static>(
self: Box<Self>
) -> Result<Box<T>, Box<Error + Send>>1.3.0
self: Box<Self>
) -> Result<Box<T>, Box<Error + Send>>
Attempt to downcast the box to a concrete type.
impl Error + Send + Sync[src]
fn downcast<T: Error + 'static>(self: Box<Self>) -> Result<Box<T>, Box<Self>>1.3.0
Attempt to downcast the box to a concrete type.
Implementors
impl Error for VarErrorimpl Error for JoinPathsErrorimpl Error for !impl Error for AllocErrimpl Error for CannotReallocInPlaceimpl Error for ParseBoolErrorimpl Error for Utf8Errorimpl Error for ParseIntErrorimpl Error for TryFromIntErrorimpl Error for ParseFloatErrorimpl Error for FromUtf8Errorimpl Error for FromUtf16Errorimpl Error for ParseErrorimpl Error for DecodeUtf16Errorimpl<T: Error> Error for Box<T>impl Error for std::fmt::Errorimpl Error for BorrowErrorimpl Error for BorrowMutErrorimpl Error for CharTryFromErrorimpl Error for ParseCharErrorimpl Error for NulErrorimpl Error for FromBytesWithNulErrorimpl Error for IntoStringErrorimpl<W: Send + Debug> Error for IntoInnerError<W>impl Error for std::io::Errorimpl Error for CharsErrorimpl Error for AddrParseErrorimpl Error for StripPrefixErrorimpl<T: Send> Error for SendError<T>impl<T: Send> Error for TrySendError<T>impl Error for RecvErrorimpl Error for TryRecvErrorimpl Error for RecvTimeoutErrorimpl Error for SystemTimeErrorimpl<T> Error for PoisonError<T>impl<T> Error for TryLockError<T>