Method unchecked_dyn_error_mut

crates/core/src/error/error.rs:1643–1646

# Safety `self.is_boxed_dyn_error()` must be true.

(&mut self)

    ///
    /// `self.is_boxed_dyn_error()` must be true.
    unsafe fn unchecked_dyn_error_mut(&mut self) -> MutPtr<'_, DynError> {
        debug_assert!(self.is_boxed_dyn_error());
        MutPtr::new(self.inner.cast::<DynError>())
    }

    pub(crate) fn unpack(&self) -> OomOrDynErrorRef<'_> {
        if self.is_oom() {