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use std::fmt;
/// An error encountered while working with structured data.
#[derive(Debug)]
pub struct Error {
inner: Inner,
}
#[derive(Debug)]
enum Inner {
#[cfg(feature = "std")]
Boxed(std_support::BoxedError),
Msg(&'static str),
#[cfg(feature = "value-bag")]
Value(crate::kv::value::inner::Error),
Fmt,
}
impl Error {
/// Create an error from a message.
pub fn msg(msg: &'static str) -> Self {
Error {
inner: Inner::Msg(msg),
}
}
// Not public so we don't leak the `crate::kv::value::inner` API
#[cfg(feature = "value-bag")]
pub(super) fn from_value(err: crate::kv::value::inner::Error) -> Self {
Error {
inner: Inner::Value(err),
}
}
// Not public so we don't leak the `crate::kv::value::inner` API
#[cfg(feature = "value-bag")]
pub(super) fn into_value(self) -> crate::kv::value::inner::Error {
match self.inner {
Inner::Value(err) => err,
#[cfg(feature = "kv_std")]
_ => crate::kv::value::inner::Error::boxed(self),
#[cfg(not(feature = "kv_std"))]
_ => crate::kv::value::inner::Error::msg("error inspecting a value"),
}
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
use self::Inner::*;
match &self.inner {
#[cfg(feature = "std")]
Boxed(err) => err.fmt(f),
#[cfg(feature = "value-bag")]
Value(err) => err.fmt(f),
Msg(msg) => msg.fmt(f),
Fmt => fmt::Error.fmt(f),
}
}
}
impl From<fmt::Error> for Error {
fn from(_: fmt::Error) -> Self {
Error { inner: Inner::Fmt }
}
}
#[cfg(feature = "std")]
mod std_support {
use super::*;
use std::{error, io};
pub(super) type BoxedError = Box<dyn error::Error + Send + Sync>;
impl Error {
/// Create an error from a standard error type.
pub fn boxed<E>(err: E) -> Self
where
E: Into<BoxedError>,
{
Error {
inner: Inner::Boxed(err.into()),
}
}
}
impl error::Error for Error {}
impl From<io::Error> for Error {
fn from(err: io::Error) -> Self {
Error::boxed(err)
}
}
}