Revision control
Copy as Markdown
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use std::fmt::Display;
use error_support::{handle_error, ErrorHandling, GetErrorHandling};
#[derive(Debug, thiserror::Error)]
struct Error {}
impl Display for Error {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "Internal Error!")
}
}
type Result<T, E = Error> = std::result::Result<T, E>;
#[derive(Debug, thiserror::Error)]
struct ExternalError {}
#[derive(Debug, thiserror::Error)]
struct OtherExternalError {}
impl Display for ExternalError {
fn fmt(&self, _: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
Ok(())
}
}
impl Display for OtherExternalError {
fn fmt(&self, _: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
Ok(())
}
}
impl GetErrorHandling for Error {
type ExternalError = OtherExternalError;
fn get_error_handling(&self) -> error_support::ErrorHandling<Self::ExternalError> {
ErrorHandling::convert(OtherExternalError {})
}
}
// handle_error expects that `Error` implements GetErrorHandling<E = ExternalError>
// instead, it implements GetErrorHandling<E = OtherExternalError>
#[handle_error(Error)]
fn func() -> Result<String, ExternalError> {
Err(Error{})
}
fn main() {}