1.0.0[−][src]Trait netxclient::Error
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, and 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
pub fn source(&self) -> Option<&(dyn Error + 'static)>
1.30.0[src]
The lower-level source 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 source(&self) -> Option<&(dyn Error + 'static)> { 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 get_super_error() -> Result<(), SuperError> { Err(SuperError { side: SuperErrorSideKick }) } fn main() { match get_super_error() { Err(e) => { println!("Error: {}", e); println!("Caused by: {}", e.source().unwrap()); } _ => println!("No error"), } }
pub fn backtrace(&self) -> Option<&Backtrace>
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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.
pub fn description(&self) -> &str
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use the Display impl or to_string()
if let Err(e) = "xc".parse::<u32>() { // Print `e` itself, no need for description(). eprintln!("Error: {}", e); }
pub fn cause(&self) -> Option<&dyn Error>
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replaced by Error::source, which can support downcasting
Implementations
impl dyn Error + 'static
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pub fn is<T>(&self) -> bool where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Returns true
if the boxed type is the same as T
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Returns some reference to the boxed value if it is of type T
, or
None
if it isn't.
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Returns some mutable reference to the boxed value if it is of type T
, or
None
if it isn't.
impl dyn Error + 'static + Send
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pub fn is<T>(&self) -> bool where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
impl dyn Error + 'static + Send + Sync
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pub fn is<T>(&self) -> bool where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: 'static + Error,
1.3.0[src]
T: 'static + Error,
Forwards to the method defined on the type dyn Error
.
impl dyn Error + 'static
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pub fn downcast<T>(
self: Box<dyn Error + 'static, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static, Global>> where
T: 'static + Error,
1.3.0[src]
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.
pub fn chain(&self) -> Chain<'_>
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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());
impl dyn Error + 'static + Send
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pub fn downcast<T>(
self: Box<dyn Error + 'static + Send, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static + Send, Global>> where
T: 'static + Error,
1.3.0[src]
self: Box<dyn Error + 'static + Send, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static + Send, Global>> where
T: 'static + Error,
Attempts to downcast the box to a concrete type.
impl dyn Error + 'static + Send + Sync
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pub fn downcast<T>(
self: Box<dyn Error + 'static + Send + Sync, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static + Send + Sync, Global>> where
T: 'static + Error,
1.3.0[src]
self: Box<dyn Error + 'static + Send + Sync, Global>
) -> Result<Box<T, Global>, Box<dyn Error + 'static + Send + Sync, Global>> where
T: 'static + Error,
Attempts to downcast the box to a concrete type.
Implementations on Foreign Types
impl Error for !
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impl<T> Error for TrySendError<T> where
T: Send,
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T: Send,
pub fn description(&self) -> &str
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impl Error for JoinPathsError
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pub fn description(&self) -> &str
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impl Error for BorrowMutError
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pub fn description(&self) -> &str
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impl Error for LayoutError
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impl<T> Error for SendError<T> where
T: Send,
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T: Send,
pub fn description(&self) -> &str
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impl Error for VarError
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pub fn description(&self) -> &str
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impl Error for StripPrefixError
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pub fn description(&self) -> &str
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impl Error for ParseCharError
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pub fn description(&self) -> &str
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impl Error for FromVecWithNulError
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impl Error for FromBytesWithNulError
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pub fn description(&self) -> &str
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impl Error for Utf8Error
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pub fn description(&self) -> &str
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impl Error for ParseIntError
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pub fn description(&self) -> &str
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impl Error for Infallible
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pub fn description(&self) -> &str
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impl Error for TryRecvError
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pub fn description(&self) -> &str
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impl Error for TryReserveError
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impl Error for AccessError
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impl Error for IntoStringError
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impl Error for TryFromIntError
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pub fn description(&self) -> &str
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impl Error for FromUtf8Error
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pub fn description(&self) -> &str
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impl<T> Error for PoisonError<T>
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pub fn description(&self) -> &str
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impl Error for CharTryFromError
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pub fn description(&self) -> &str
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impl Error for Error
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pub fn description(&self) -> &str
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impl<T> Error for Box<T, Global> where
T: Error,
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T: Error,
pub fn description(&self) -> &str
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pub fn cause(&self) -> Option<&dyn Error>
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pub fn source(&self) -> Option<&(dyn Error + 'static)>
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impl Error for TryFromSliceError
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pub fn description(&self) -> &str
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impl Error for ParseBoolError
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pub fn description(&self) -> &str
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impl Error for NulError
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pub fn description(&self) -> &str
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impl Error for DecodeUtf16Error
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pub fn description(&self) -> &str
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impl Error for FromUtf16Error
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pub fn description(&self) -> &str
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impl Error for BorrowError
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pub fn description(&self) -> &str
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impl<T> Error for TryLockError<T>
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impl Error for RecvTimeoutError
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pub fn description(&self) -> &str
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impl Error for RecvError
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pub fn description(&self) -> &str
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impl<W> Error for IntoInnerError<W> where
W: Send + Debug,
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W: Send + Debug,
pub fn description(&self) -> &str
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impl Error for AllocError
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impl Error for AddrParseError
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pub fn description(&self) -> &str
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impl Error for Error
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pub fn description(&self) -> &str
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pub fn cause(&self) -> Option<&dyn Error>
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pub fn source(&self) -> Option<&(dyn Error + 'static)>
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impl Error for ParseFloatError
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pub fn description(&self) -> &str
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impl Error for SystemTimeError
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pub fn description(&self) -> &str
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impl Error for AError
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impl<T> Error for PushError<T> where
T: Debug,
T: Debug,
impl Error for PopError
impl Error for ReuniteError
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impl Error for Elapsed
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impl Error for RecvError
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impl Error for JoinError
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impl Error for TryAcquireError
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impl<T> Error for SendError<T> where
T: Debug,
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T: Debug,
impl Error for TryRecvError
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impl Error for AcquireError
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impl Error for ReuniteError
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impl<T> Error for SendError<T> where
T: Debug,
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T: Debug,
impl<T> Error for SendError<T> where
T: Debug,
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T: Debug,
impl Error for RecvError
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impl Error for Error
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impl Error for TryRecvError
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impl<T> Error for TrySendError<T> where
T: Debug,
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T: Debug,
impl Error for RecvError
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impl Error for RecvError
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impl<T> Error for SendTimeoutError<T> where
T: Debug,
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T: Debug,