- rust: 1.32.0

    - rust: 1.34.0

use std::convert::Infallible;

    }
}
/// ```
/// # type T = ();
/// #
/// use anyhow::{Context, Result};
///
/// fn maybe_get() -> Option<T> {
///     # const IGNORE: &str = stringify! {
///     ...
///     # };
///     # unimplemented!()
/// }
///
/// fn demo() -> Result<()> {
///     let t = maybe_get().context("there is no T")?;
///     # const IGNORE: &str = stringify! {
///     ...
///     # };
///     # unimplemented!()
/// }
/// ```
impl<T> Context<T, Infallible> for Option<T> {
    fn context<C>(self, context: C) -> Result<T, Error>
    where
        C: Display + Send + Sync + 'static,
    {
        self.ok_or_else(|| Error::from_display(context, backtrace!()))

    fn with_context<C, F>(self, context: F) -> Result<T, Error>
    where
        C: Display + Send + Sync + 'static,
        F: FnOnce() -> C,
    {
        self.ok_or_else(|| Error::from_display(context(), backtrace!()))
    }

        // same layout as the typeid specifies.
        unsafe { Error::construct(error, type_id, backtrace) }
    }
    pub(crate) fn from_display<M>(message: M, backtrace: Option<Backtrace>) -> Self
    where
        M: Display + Send + Sync + 'static,
    {
        let error = DisplayError(message);
        let type_id = TypeId::of::<M>();
        // Safety: DisplayError is repr(transparent) so DisplayError<M> has the

#[repr(transparent)]
struct DisplayError<M>(M);
impl<M> Debug for DisplayError<M>
where
    M: Display,
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        Display::fmt(&self.0, f)
    }
}
impl<M> Display for DisplayError<M>
where
    M: Display,
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        Display::fmt(&self.0, f)
    }
}
impl<M> StdError for DisplayError<M> where M: Display + 'static {}