Struct wasmtime_wasi::preview2::TrappableError

pub struct TrappableError<T> { /* private fields */ }

A helper error type used by many other modules through type aliases.

This type is an Error itself and is intended to be a representation of either:

• A custom error type T
• A trap, represented as anyhow::Error

This error is created through either the ::trap constructor representing a full-fledged trap or the From<T> constructor which is intended to be used with ?. The goal is to make normal errors T “automatic” but enable error paths to return a ::trap error optionally still as necessary without extra boilerplate everywhere else.

Note that this type isn’t used directly but instead is intended to be used as:

type MyError = TrappableError<bindgen::TheError>;

where MyError is what you’ll use throughout bindings code and bindgen::TheError is the type that this represents as generated by the bindgen! macro.

Implementations

impl<T> TrappableError<T>

pub fn trap(err: impl Into<Error>) -> TrappableError<T>

pub fn downcast(self) -> Result<T>

where T: Error + Send + Sync + 'static,

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

where T: Error + Send + Sync + 'static,

Trait Implementations

impl<T> Debug for TrappableError<T>

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

Formats the value using the given formatter.

impl<T> Display for TrappableError<T>

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

Formats the value using the given formatter.

impl<T> Error for TrappableError<T>

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

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

fn description(&self) -> &str

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

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.

impl<T> From<T> for TrappableError<T>

where T: Error + Send + Sync + 'static,

fn from(error: T) -> Self

Converts to this type from the input type.

impl From<TrappableError<ErrorCode>> for Error

fn from(err: FsError) -> Self

Converts to this type from the input type.