Trait gclient::ext::sp_core::serde::ser::StdError

pub trait StdError: Debug + Display {
    // Provided methods
    fn source(&self) -> Option<&(dyn Error + 'static)> { ... }
    fn description(&self) -> &str { ... }
    fn cause(&self) -> Option<&dyn Error> { ... }
    fn provide<'a>(&'a self, request: &mut Request<'a>) { ... }
}

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 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.

Provided Methods

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

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"),
    }
}

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

if let Err(e) = "xc".parse::<u32>() {
    // Print `e` itself, no need for description().
    eprintln!("Error: {e}");
}

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.

Used in conjunction with Request::provide_value and Request::provide_ref to extract references to member variables from dyn Error trait objects.

Example

#![feature(error_generic_member_access)]
#![feature(error_in_core)]
use core::fmt;
use core::error::{request_ref, Request};

#[derive(Debug)]
enum MyLittleTeaPot {
    Empty,
}

#[derive(Debug)]
struct MyBacktrace {
    // ...
}

impl MyBacktrace {
    fn new() -> MyBacktrace {
        // ...
    }
}

#[derive(Debug)]
struct Error {
    backtrace: MyBacktrace,
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Example Error")
    }
}

impl std::error::Error for Error {
    fn provide<'a>(&'a self, request: &mut Request<'a>) {
        request
            .provide_ref::<MyBacktrace>(&self.backtrace);
    }
}

fn main() {
    let backtrace = MyBacktrace::new();
    let error = Error { backtrace };
    let dyn_error = &error as &dyn std::error::Error;
    let backtrace_ref = request_ref::<MyBacktrace>(dyn_error).unwrap();

    assert!(core::ptr::eq(&error.backtrace, backtrace_ref));
    assert!(request_ref::<MyLittleTeaPot>(dyn_error).is_none());
}

Implementations

impl dyn Error

pub fn is<T>(&self) -> bool

where T: Error + 'static,

Returns true if the inner type is the same as T.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: Error + 'static,

Returns some reference to the inner 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: Error + 'static,

Returns some mutable reference to the inner value if it is of type T, or None if it isn’t.

impl dyn Error + Send

pub fn is<T>(&self) -> bool

where T: Error + 'static,

Forwards to the method defined on the type dyn Error.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: Error + 'static,

Forwards to the method defined on the type dyn Error.

pub fn downcast_mut<T>(&mut self) -> Option<&mut T>

where T: Error + 'static,

Forwards to the method defined on the type dyn Error.

impl dyn Error + Send + Sync

pub fn is<T>(&self) -> bool

where T: Error + 'static,

Forwards to the method defined on the type dyn Error.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: Error + 'static,

Forwards to the method defined on the type dyn Error.

pub fn downcast_mut<T>(&mut self) -> Option<&mut T>

where T: Error + 'static,

Forwards to the method defined on the type dyn Error.

impl dyn Error

pub fn sources(&self) -> Source<'_>

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

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

pub fn downcast<T>(self: Box<dyn Error>) -> Result<Box<T>, Box<dyn Error>>

where T: Error + 'static,

Attempts to downcast the box to a concrete type.

impl dyn Error + Send

pub fn downcast<T>( self: Box<dyn Error + Send> ) -> Result<Box<T>, Box<dyn Error + Send>>

where T: Error + 'static,

Attempts to downcast the box to a concrete type.

impl dyn Error + Send + Sync

pub fn downcast<T>( self: Box<dyn Error + Send + Sync> ) -> Result<Box<T>, Box<dyn Error + Send + Sync>>

where T: Error + 'static,

Attempts to downcast the box to a concrete type.

Trait Implementations

impl AsRef<dyn Error> for Error

fn as_ref(&self) -> &(dyn Error + 'static)

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<dyn Error + Send + Sync> for Error

fn as_ref(&self) -> &(dyn Error + Send + Sync + 'static)

Converts this type into a shared reference of the (usually inferred) input type.

impl From<&str> for Box<dyn Error>

fn from(err: &str) -> Box<dyn Error>

Converts a str into a box of dyn Error.

Examples

use std::error::Error;
use std::mem;

let a_str_error = "a str error";
let a_boxed_error = Box::<dyn Error>::from(a_str_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl<'a> From<&str> for Box<dyn Error + Send + Sync + 'a>

fn from(err: &str) -> Box<dyn Error + Send + Sync + 'a>

Converts a str into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::mem;

let a_str_error = "a str error";
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_str_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl From<ColoredString> for Box<dyn Error>

fn from(cs: ColoredString) -> Box<dyn Error>

Converts to this type from the input type.

impl<'a> From<Cow<'a, str>> for Box<dyn Error>

fn from(err: Cow<'a, str>) -> Box<dyn Error>

Converts a Cow into a box of dyn Error.

Examples

use std::error::Error;
use std::mem;
use std::borrow::Cow;

let a_cow_str_error = Cow::from("a str error");
let a_boxed_error = Box::<dyn Error>::from(a_cow_str_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl<'a, 'b> From<Cow<'b, str>> for Box<dyn Error + Send + Sync + 'a>

fn from(err: Cow<'b, str>) -> Box<dyn Error + Send + Sync + 'a>

Converts a Cow into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::mem;
use std::borrow::Cow;

let a_cow_str_error = Cow::from("a str error");
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_cow_str_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl<'a, E> From<E> for Box<dyn Error + 'a>

where E: Error + 'a,

fn from(err: E) -> Box<dyn Error + 'a>

Converts a type of Error into a box of dyn Error.

Examples

use std::error::Error;
use std::fmt;
use std::mem;

#[derive(Debug)]
struct AnError;

impl fmt::Display for AnError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "An error")
    }
}

impl Error for AnError {}

let an_error = AnError;
assert!(0 == mem::size_of_val(&an_error));
let a_boxed_error = Box::<dyn Error>::from(an_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl<'a, E> From<E> for Box<dyn Error + Send + Sync + 'a>

where E: Error + Send + Sync + 'a,

fn from(err: E) -> Box<dyn Error + Send + Sync + 'a>

Converts a type of Error + Send + Sync into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::fmt;
use std::mem;

#[derive(Debug)]
struct AnError;

impl fmt::Display for AnError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "An error")
    }
}

impl Error for AnError {}

unsafe impl Send for AnError {}

unsafe impl Sync for AnError {}

let an_error = AnError;
assert!(0 == mem::size_of_val(&an_error));
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(an_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl From<Error> for Box<dyn Error>

fn from(error: Error) -> Box<dyn Error>

Converts to this type from the input type.

impl From<Error> for Box<dyn Error + Send>

fn from(error: Error) -> Box<dyn Error + Send>

Converts to this type from the input type.

impl From<Error> for Box<dyn Error + Send + Sync>

fn from(error: Error) -> Box<dyn Error + Send + Sync>

Converts to this type from the input type.

impl From<String> for Box<dyn Error>

fn from(str_err: String) -> Box<dyn Error>

Converts a String into a box of dyn Error.

Examples

use std::error::Error;
use std::mem;

let a_string_error = "a string error".to_string();
let a_boxed_error = Box::<dyn Error>::from(a_string_error);
assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))

impl From<String> for Box<dyn Error + Send + Sync>

fn from(err: String) -> Box<dyn Error + Send + Sync>

Converts a String into a box of dyn Error + Send + Sync.

Examples

use std::error::Error;
use std::mem;

let a_string_error = "a string error".to_string();
let a_boxed_error = Box::<dyn Error + Send + Sync>::from(a_string_error);
assert!(
    mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))

impl Value for dyn Error

fn record(&self, key: &Field, visitor: &mut dyn Visit)

Visits this value with the given Visitor.

impl Value for dyn Error + Send

fn record(&self, key: &Field, visitor: &mut dyn Visit)

Visits this value with the given Visitor.

impl Value for dyn Error + Send + Sync

fn record(&self, key: &Field, visitor: &mut dyn Visit)

Visits this value with the given Visitor.

impl Value for dyn Error + Sync

fn record(&self, key: &Field, visitor: &mut dyn Visit)

Visits this value with the given Visitor.

Implementors

impl !Error for &str

impl Error for gsdk::result::Error

impl Error for TxError

impl Error for gsdk::testing::result::Error

impl Error for gclient::Error

impl Error for gclient::errors::ModuleError

impl Error for DeriveError

impl Error for SecretStringError

impl Error for TransactionValidityError

impl Error for PublicError

impl Error for Infallible

impl Error for RecvTimeoutError

impl Error for gclient::ext::sp_core::sp_std::sync::mpsc::TryRecvError

impl Error for webpki::error::Error

Requires the std feature.

impl Error for VarError

impl Error for bincode::error::ErrorKind

impl Error for RoundingError

impl Error for hex::error::FromHexError

impl Error for url::parser::ParseError

impl Error for rand::distributions::bernoulli::BernoulliError

impl Error for rand::distributions::bernoulli::BernoulliError

impl Error for rand::distributions::weighted::WeightedError

impl Error for rand::distributions::weighted_index::WeightedError

impl Error for !

impl Error for gclient::ext::sp_runtime::codec::Error

impl Error for SystemTimeError

impl Error for TryFromFloatSecsError

impl Error for gclient::ext::sp_core::bounded::alloc::collections::TryReserveError

impl Error for FromVecWithNulError

impl Error for IntoStringError

impl Error for NulError

impl Error for ParseBoolError

impl Error for gclient::ext::sp_core::bounded::alloc::str::Utf8Error

impl Error for gclient::ext::sp_core::bounded::alloc::string::FromUtf8Error

impl Error for FromUtf16Error

impl Error for AllocError

impl Error for LayoutError

impl Error for BorrowError

impl Error for BorrowMutError

impl Error for ParseFloatError

impl Error for ParseIntError

impl Error for TryFromIntError

impl Error for gclient::ext::sp_core::sp_std::sync::mpsc::RecvError

impl Error for gclient::ext::sp_core::serde::de::value::Error

impl Error for webpki::subject_name::dns_name::InvalidDnsNameError

Requires the std feature.

impl Error for webpki::subject_name::ip_address::AddrParseError

Requires the std feature.

impl Error for TryFromSliceError

impl Error for CharTryFromError

impl Error for ParseCharError

impl Error for DecodeUtf16Error

impl Error for TryFromCharError

impl Error for FromBytesUntilNulError

impl Error for FromBytesWithNulError

impl Error for core::fmt::Error

impl Error for core::net::parser::AddrParseError

impl Error for JoinPathsError

impl Error for WriterPanicked

impl Error for std::io::error::Error

impl Error for StripPrefixError

impl Error for ExitStatusError

impl Error for AccessError

impl Error for chrono::format::ParseError

impl Error for ParseMonthError

impl Error for OutOfRange

impl Error for chrono::time_delta::OutOfRangeError

impl Error for ParseWeekdayError

impl Error for getrandom::error::Error

impl Error for h2::error::Error

impl Error for LengthLimitError

impl Error for http::error::Error

impl Error for InvalidHeaderName

impl Error for InvalidHeaderValue

impl Error for ToStrError

impl Error for InvalidMethod

impl Error for InvalidStatusCode

impl Error for InvalidUri

impl Error for InvalidUriParts

impl Error for log::ParseLevelError

impl Error for SetLoggerError

impl Error for ParseBigIntError

impl Error for num_format::error::Error

impl Error for ParseRatioError

impl Error for serde_json::error::Error

impl Error for tracing_subscriber::filter::directive::ParseError

impl Error for BadName

impl Error for FromEnvError

impl Error for tracing_subscriber::reload::Error

impl Error for TryInitError

impl Error for getrandom::error::Error

impl Error for rand::rngs::adapter::read::ReadError

impl Error for rand::rngs::adapter::read::ReadError

impl Error for rand_core::error::Error

impl Error for rand_core::error::Error

impl Error for Aborted

impl Error for AcquireError

impl Error for AddrParseError

impl Error for AnyDelimiterCodecError

impl Error for ArithmeticError

impl Error for BinaryReaderError

impl Error for BinaryReaderError

impl Error for BlockError

impl Error for BuildError

impl Error for BuildError

impl Error for BuildError

impl Error for BuildError

impl Error for BuildError

impl Error for CacheError

impl Error for CallError

impl Error for Canceled

impl Error for CaseFoldError

impl Error for CaseFoldError

impl Error for ColorChoiceParseError

impl Error for CompileError

impl Error for ConvertError

impl Error for DecodeError

impl Error for DecodeError

impl Error for DecodeError

impl Error for DecodeSliceError

impl Error for DeserializeError

impl Error for DeserializerError

impl Error for DispatchError

impl Error for Elapsed

impl Error for Elapsed

impl Error for EncodeSliceError

impl Error for EnterError

impl Error for Errno

impl Error for Errno

impl Error for Errno

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for Error

impl Error for ErrorCode

impl Error for ErrorCode

impl Error for ErrorKind

impl Error for Errors

impl Error for ExecutionError

impl Error for ExtrinsicParamsError

impl Error for FromDecStrErr

impl Error for FromHexError

impl Error for FromHexError

impl Error for FromMetadataError

impl Error for FromStrRadixErr

impl Error for FromUtf8Error

impl Error for GenericTransportError

impl Error for GetTimezoneError

impl Error for GroupInfoError

impl Error for InvalidBufferSize

impl Error for InvalidDnsNameError

impl Error for InvalidDnsNameError

impl Error for InvalidLength

impl Error for InvalidNameError

impl Error for InvalidOutputSize

impl Error for InvalidOutputSize

impl Error for InvalidParityValue

impl Error for InvalidRequestId

impl Error for JoinError

impl Error for LengthDelimitedCodecError

impl Error for LinesCodecError

impl Error for MacError

impl Error for MatchError

impl Error for MatchError

impl Error for MemoryAccessError

impl Error for MetadataError

impl Error for ModuleError

impl Error for OutOfRangeError

impl Error for ParseAlphabetError

impl Error for ParseColorError

impl Error for ParseError

impl Error for ParseError

impl Error for ParseError

impl Error for ParseError

impl Error for ParseHexError

impl Error for ParseLevelError

impl Error for ParseLevelFilterError

impl Error for PatternIDError

impl Error for PatternIDError

impl Error for PatternSetInsertError

impl Error for RecvError

impl Error for RecvError

impl Error for RecvError

impl Error for ReuniteError

impl Error for ReuniteError

impl Error for RpcError

impl Error for SendError

impl Error for SerializeError

impl Error for SerializerError

impl Error for SetGlobalDefaultError

impl Error for SignError

impl Error for SliceTooLarge

impl Error for SmallIndexError

impl Error for SpawnError

impl Error for StateIDError

impl Error for StateIDError

impl Error for StorageAddressError

impl Error for TokenError

impl Error for TransactionError

impl Error for TransactionalError

impl Error for Trap

impl Error for Trap

impl Error for TryAcquireError

impl Error for TryCurrentError

impl Error for TryFromError

impl Error for TryLockError

impl Error for TryRecvError

impl Error for TryRecvError

impl Error for TryRecvError

impl Error for TryRecvError

impl Error for TryReserveError

impl Error for UnicodeWordBoundaryError

impl Error for UnicodeWordError

impl Error for UnicodeWordError

impl Error for UnknownImportError

impl Error for UnknownOpCode

impl Error for Utf8Error

impl Error for WasmError

impl Error for WsError

impl Error for WsError

impl Error for WsHandshakeError

impl Error for WsHandshakeError

impl<'a> Error for ErrorObject<'a>

impl<'a, K, V> Error for gclient::ext::sp_core::bounded::alloc::collections::btree_map::OccupiedError<'a, K, V>

where K: Debug + Ord, V: Debug,

impl<'a, K, V> Error for std::collections::hash::map::OccupiedError<'a, K, V>

where K: Debug, V: Debug,

impl<'a, T> Error for &'a T

where T: Error + ?Sized,

impl<H> Error for Error<H>

where Error<H>: Debug + Display,

impl<H, CodecError> Error for Error<H, CodecError>

where Error<H, CodecError>: Debug + Display,

impl<HO, CE> Error for Error<HO, CE>

where HO: Debug, CE: Error + 'static,

impl<L, R> Error for Either<L, R>

where L: Error, R: Error,

Either implements Error if both L and R implement it.

impl<R> Error for BitIdxError<R>

where R: BitRegister,

impl<T> Error for gclient::ext::sp_core::sp_std::sync::TryLockError<T>

impl<T> Error for gclient::ext::sp_core::sp_std::sync::mpsc::TrySendError<T>

impl<T> Error for ThinBox<T>

where T: Error + ?Sized,

impl<T> Error for Box<T>

where T: Error,

impl<T> Error for gclient::ext::sp_core::sp_std::sync::mpsc::SendError<T>

impl<T> Error for Arc<T>

where T: Error + ?Sized,

impl<T> Error for PoisonError<T>

impl<T> Error for CapacityError<T>

where T: Any,

Requires features="std".

impl<T> Error for TryFromBigIntError<T>

where T: Debug,

impl<T> Error for AsyncFdTryNewError<T>

impl<T> Error for BitPtrError<T>

where T: BitStore,

impl<T> Error for BitSpanError<T>

where T: BitStore,

impl<T> Error for GenericTransportError<T>

where T: Error + Send + Sync, GenericTransportError<T>: Debug + Display,

impl<T> Error for MisalignError<T>

impl<T> Error for PollSendError<T>

where T: Debug,

impl<T> Error for ReuniteError<T>

where T: Any,

impl<T> Error for ReuniteError<T>

where T: Any,

impl<T> Error for SendError<T>

impl<T> Error for SendError<T>

impl<T> Error for SendError<T>

where T: Debug,

impl<T> Error for SendTimeoutError<T>

impl<T> Error for SetError<T>

where T: Debug,

impl<T> Error for TrySendError<T>

impl<T> Error for TrySendError<T>

where T: Any,

impl<T, E> Error for TrieError<T, E>

where T: Debug, E: Error,

impl<T, E> Error for TryChunksError<T, E>

where E: Debug + Display,

impl<T, E> Error for TryReadyChunksError<T, E>

where E: Debug + Display,

impl<T, Item> Error for ReuniteError<T, Item>

where T: Any,

impl<W> Error for IntoInnerError<W>

where W: Send + Debug,

impl<const N: usize> Error for GetManyMutError<N>