Method downcast_mut

libs/error-stack/src/report.rs:710–722

(&mut self)

    /// `T` can either be an attachment or a new [`Error`] context.
    #[must_use]
    pub fn downcast_mut<T: Send + Sync + 'static>(&mut self) -> Option<&mut T> {
        // This cannot use `frames_mut` as the found reference needs to outlive the visitor
        // closure. Each frame is either returned or descended into, never both, so the borrow
        // checker accepts this without `unsafe`.
        let mut stack = vec![self.frames.iter_mut()];
        while let Some(frame) = iter::next(&mut stack) {
            if frame.is::<T>() {
                return frame.downcast_mut();
            }
            stack.push(frame.sources_mut().iter_mut());
        }
        None
    }
}

impl<C> Report<[C]> {