Struct extracterr::Bundled

pub struct Bundled<E, C: 'static> { /* fields omitted */ }

An Error bundled with a Context can then later be extracted from a chain of dyn Errors.

Usage

This type has two primary methods of construction, From and Bundle. The first method of construction, the From trait, only works when the type you're bundling with the error implements Default. This is useful for types like Backtraces where the context you care about is implicitly captured just by constructing the type, or for types that have a reasonable default like HttpStatusCodes defaulting to 500.

use extracterr::Bundled;

#[derive(Debug, thiserror::Error)]
#[error("just an example error")]
struct ExampleError;

struct StatusCode(u32);

impl Default for StatusCode {
    fn default() -> Self {
        Self(500)
    }
}


fn foo() -> Result<(), Bundled<ExampleError, StatusCode>> {
    Err(ExampleError)?
}

The second method of construction, the Bundle trait, lets you attach context to errors manually. This is useful for types that don't implement Default or types where you only occasionally want to override the defaults.

use extracterr::{Bundled, Bundle};

#[derive(Debug, thiserror::Error)]
#[error("just an example error")]
struct ExampleError;

struct StatusCode(u32);

fn foo() -> Result<(), Bundled<ExampleError, StatusCode>> {
    Err(ExampleError).bundle(StatusCode(404))?
}

Once context has been bundled with an error it can then be extracted by an error reporter with the Extract trait.

Implementations

impl<E, C: 'static> Bundled<E, C>

pub fn inner(&self) -> &E

Returns a reference to the inner error

Trait Implementations

impl<E, C> Debug for Bundled<E, C> where
    E: Error, 

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<E, C> Display for Bundled<E, C> where
    E: Error, 

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<E, C> Error for Bundled<E, C> where
    E: Error + 'static, 

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

The lower-level source of this error, if any.

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

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

Returns a stack backtrace, if available, of where this error occurred.

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

impl<E, C> From<E> for Bundled<E, C> where
    E: Error + Send + Sync + 'static,
    C: Default, 

fn from(error: E) -> Self

Performs the conversion.