Enum semeion::error::Error

pub enum Error {
    Unknown,
    Code(i32),
    Message(String),
    Any(Box<dyn Any + Send>),
}

Represents any possible error.

This enum allows to encode the errors that can be raised by this library as well as allow to encode a custom error, that will need to be propagated via the APIs exposed by this library, which originates in the user's code.

Variants

Unknown

The most generic and possibly useless type of error, to be raised when no other information is available.

Code(i32)

The Code variant allows to encode errors as simple signed integers.

Message(String)

The Message variant allows to encode the error as a string.

Any(Box<dyn Any + Send>)

The Any variant allows to encode any type of error with performance costs due to the heap allocations, and type erasure.

Example

use std::fmt;

#[derive(Debug)]
enum MyError {
    Audio,
    Game,
    InvalidArg { err: String }
}

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

impl std::error::Error for MyError {}

impl semeion::error::Any for MyError {
    fn as_any(&self) -> &dyn std::any::Any {
        self
    }
}

// we can get a `semeion::Error` from any of the public APIs
let err = semeion::Error::with_err(MyError::Audio);

// and downcast it back to its original concrete type with
if let semeion::Error::Any(err) = err {
    let my_err = err.as_any().downcast_ref::<MyError>().unwrap();
}

Implementations

impl Error

pub fn with_message(message: impl Display) -> Self

Constructs a new Error with the given message.

pub fn with_err(err: impl Any + Send + 'static) -> Self

Constructs a new Error with the given custom value.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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

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

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

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

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

pub fn description(&self) -> &str

👎 Deprecated since 1.42.0:

use the Display impl or to_string()

pub fn cause(&self) -> Option<&dyn Error>

👎 Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting