Trait ChainedError

pub trait ChainedError:
    Error
    + Send
    + 'static {
    type ErrorKind;

    // Required methods
    fn from_kind(kind: Self::ErrorKind) -> Self
       where Self: Sized;
    fn with_chain<E, K>(error: E, kind: K) -> Self
       where Self: Sized,
             E: Error + Send + 'static,
             K: Into<Self::ErrorKind>;
    fn kind(&self) -> &Self::ErrorKind;
    fn iter(&self) -> Iter<'_> ;
    fn backtrace(&self) -> Option<&Backtrace>;
    fn chain_err<F, EK>(self, error: F) -> Self
       where F: FnOnce() -> EK,
             EK: Into<Self::ErrorKind>;

    // Provided method
    fn display_chain<'a>(&'a self) -> DisplayChain<'a, Self> { ... }
}

This trait is implemented on all the errors generated by the error_chain macro.

Required Associated Types

type ErrorKind

Associated kind type.

Required Methods

fn from_kind(kind: Self::ErrorKind) -> Self

where Self: Sized,

Constructs an error from a kind, and generates a backtrace.

fn with_chain<E, K>(error: E, kind: K) -> Self

where Self: Sized, E: Error + Send + 'static, K: Into<Self::ErrorKind>,

Constructs a chained error from another error and a kind, and generates a backtrace.

fn kind(&self) -> &Self::ErrorKind

Returns the kind of the error.

fn iter(&self) -> Iter<'_>

Iterates over the error chain.

fn backtrace(&self) -> Option<&Backtrace>

Returns the backtrace associated with this error.

fn chain_err<F, EK>(self, error: F) -> Self

where F: FnOnce() -> EK, EK: Into<Self::ErrorKind>,

Extends the error chain with a new entry.

Provided Methods

fn display_chain<'a>(&'a self) -> DisplayChain<'a, Self>

Returns an object which implements Display for printing the full context of this error.

The full cause chain and backtrace, if present, will be printed.

Examples found in repository

examples/quickstart.rs (line 59)

fn alternative_main() {
    if let Err(ref e) = run() {
        use error_chain::ChainedError;
        use std::io::Write; // trait which holds `display_chain`
        let stderr = &mut ::std::io::stderr();
        let errmsg = "Error writing to stderr";

        writeln!(stderr, "{}", e.display_chain()).expect(errmsg);
        ::std::process::exit(1);
    }
}

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl ChainedError for error_chain::example_generated::inner::Error

type ErrorKind = ErrorKind

impl ChainedError for error_chain::example_generated::Error

type ErrorKind = ErrorKind