Trait otter_api_tests::shapelib::Error 1.0.0[−][src]
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 { 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"), } }
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
[src]
fn description(&self) -> &str
[src]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
Returns true
if the boxed type is the same as T
Returns some reference to the boxed value if it is of type T
, or
None
if it isn’t.
Returns some mutable reference to the boxed value if it is of type T
, or
None
if it isn’t.
Forwards to the method defined on the type dyn Error
.
Forwards to the method defined on the type dyn Error
.
Forwards to the method defined on the type dyn Error
.
Forwards to the method defined on the type dyn Error
.
Forwards to the method defined on the type dyn Error
.
Forwards to the method defined on the type dyn Error
.
Attempts to downcast the box to a concrete type.
🔬 This is a nightly-only experimental API. (error_iter
)
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
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
replaced by Error::source, which can support downcasting
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for UnicodeWordError
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for CaseFoldError
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for ParseColorError
impl Error for ParseColorError
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
use the Display impl or to_string()
impl Error for Errors
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for LimitError
impl Error for UnsupportedError
impl Error for Error
impl Error for EncodingError
impl Error for EncodingError
impl Error for DecodingError
impl Error for DecodingError
use the Display impl or to_string()
impl Error for Error
impl Error for GlobError
impl Error for GlobError
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for Utf8Error
impl Error for Utf8Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for FromUtf8Error
impl Error for FromUtf8Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for Aborted
impl Error for SpawnError
impl Error for TryRecvError
impl Error for TryLockError
impl Error for TryRecvError
impl Error for JoinError
impl Error for RecvError
impl Error for RecvError
impl Error for ReuniteError
impl Error for AcquireError
impl Error for ReuniteError
impl Error for TryAcquireError
impl Error for Elapsed
impl Error for RecvError
impl Error for Error
impl Error for RecvError
impl Error for InvalidNameError
impl Error for SendError
impl Error for Canceled
impl Error for TryRecvError
impl Error for Error
impl Error for Error
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
impl Error for LinesCodecError
impl Error for AnyDelimiterCodecError
impl Error for LengthDelimitedCodecError
use the Display impl or to_string()
impl Error for Error
impl Error for Error
👎 Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
replaced by Error::source, which can support downcasting
The lower-level cause of this error, in the case of a Utf8
error.
The lower-level source of this error, in the case of a Utf8
error.
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
Implementors
use the Display impl or to_string()
impl Error for FlexiLoggerError
impl Error for FlexiLoggerError
impl Error for DecodeError
impl Error for DecodeError
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
use the Display impl or to_string()
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for LogicError
impl Error for LogicError
use the Display impl or to_string()
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for PosCFromIteratorError
use the Display impl or to_string()
impl Error for InvalidOutputSize
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for FloatIsNan
impl Error for FloatIsNan
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
use the Display impl or to_string()
impl Error for otter_api_tests::zcoord::ParseError
impl Error for RangeBackwards
impl Error for TotallyUnboundedRange
impl Error for InvalidPassword
impl Error for CoordinateOverflow
use the Display impl or to_string()
use the Display impl or to_string()
impl<'a, K, V> Error for otter_api_tests::hash_map::OccupiedError<'a, K, V> where
K: Debug,
V: Debug,
[src]
impl<'a, K, V> Error for otter_api_tests::hash_map::OccupiedError<'a, K, V> where
K: Debug,
V: Debug,
[src]use the Display impl or to_string()
impl<E> Error for ParseNotNanError<E> where
E: 'static + Debug + Error,
impl<E> Error for ParseNotNanError<E> where
E: 'static + Debug + Error,
pub fn description(&self) -> &str
pub fn description(&self) -> &str
use the Display impl or to_string()
pub fn description(&self) -> &'static str
pub fn description(&self) -> &'static str
use the Display impl or to_string()
Either
implements Error
if both L
and R
implement it.
use the Display impl or to_string()
Requires features="std"
.
use the Display impl or to_string()
use the Display impl or to_string()
replaced by Error::source, which can support downcasting
use the Display impl or to_string()