use std::fmt;
#[derive(Debug)]
pub struct Error {
inner: Inner,
}
#[derive(Debug)]
enum Inner {
#[cfg(feature = "std")]
Boxed(std_support::BoxedError),
Msg(&'static str),
Fmt,
}
impl Error {
pub fn msg(msg: &'static str) -> Self {
Error {
inner: Inner::Msg(msg),
}
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use self::Inner::*;
match &self.inner {
#[cfg(feature = "std")]
&Boxed(ref err) => err.fmt(f),
&Msg(ref msg) => msg.fmt(f),
&Fmt => fmt::Error.fmt(f),
}
}
}
impl From<fmt::Error> for Error {
fn from(_: fmt::Error) -> Self {
Error { inner: Inner::Fmt }
}
}
impl From<Error> for fmt::Error {
fn from(_: Error) -> Self {
fmt::Error
}
}
#[cfg(feature = "std")]
mod std_support {
use super::*;
use std::{error, io};
pub(super) type BoxedError = Box<dyn error::Error + Send + Sync>;
impl Error {
pub fn boxed<E>(err: E) -> Self
where
E: Into<BoxedError>,
{
Error {
inner: Inner::Boxed(err.into()),
}
}
}
impl error::Error for Error {
fn description(&self) -> &str {
"key values error"
}
}
impl From<io::Error> for Error {
fn from(err: io::Error) -> Self {
Error::boxed(err)
}
}
impl From<Error> for io::Error {
fn from(err: Error) -> Self {
io::Error::new(io::ErrorKind::Other, err)
}
}
}