Module std::error [] [src]

Traits for working with Errors.

The Error`Error` trait

Error`Erroris a trait representing the basic expectations for error values, i.e. values of type` is a trait representing the basic expectations for error values, i.e. values of type E`Ein` in Result<T, E>`Result. At a minimum, errors must provide a description, but they may optionally provide additional detail (via`. At a minimum, errors must provide a description, but they may optionally provide additional detail (via Display`Display`) and cause chain information:

fn main() { use std::fmt::Display; trait Error: Display { fn description(&self) -> &str; fn cause(&self) -> Option<&Error> { None } } }
use std::fmt::Display;

trait Error: Display {
    fn description(&self) -> &str;

    fn cause(&self) -> Option<&Error> { None }
}

The cause`causemethod is generally used when errors cross "abstraction boundaries", i.e. when a one module must report an error that is "caused" by an error from a lower-level module. This setup makes it possible for the high-level module to provide its own errors that do not commit to any particular implementation, but also reveal some of its implementation for debugging via` method is generally used when errors cross "abstraction boundaries", i.e. when a one module must report an error that is "caused" by an error from a lower-level module. This setup makes it possible for the high-level module to provide its own errors that do not commit to any particular implementation, but also reveal some of its implementation for debugging via cause`cause` chains.

Traits

Error

Base functionality for all errors in Rust.