async_std/io/
utils.rs

1use crate::utils::Context;
2
3use std::{error::Error as StdError, fmt, io};
4
5/// Wrap `std::io::Error` with additional message
6///
7/// Keeps the original error kind and stores the original I/O error as `source`.
8impl<T> Context for Result<T, std::io::Error> {
9    fn context(self, message: impl Fn() -> String) -> Self {
10        self.map_err(|e| VerboseError::wrap(e, message()))
11    }
12}
13
14#[derive(Debug)]
15pub(crate) struct VerboseError {
16    source: io::Error,
17    message: String,
18}
19
20impl VerboseError {
21    pub(crate) fn wrap(source: io::Error, message: impl Into<String>) -> io::Error {
22        io::Error::new(
23            source.kind(),
24            VerboseError {
25                source,
26                message: message.into(),
27            },
28        )
29    }
30}
31
32impl fmt::Display for VerboseError {
33    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
34        write!(f, "{}", self.message)
35    }
36}
37
38impl StdError for VerboseError {
39    fn source(&self) -> Option<&(dyn StdError + 'static)> {
40        Some(&self.source)
41    }
42}
async_std/io/utils.rs

async_std/io/
utils.rs
