blob: d1644caf075ad663dd410f5dd1fd170346cb502b [file] [log] [blame]
use core::any::TypeId;
use Fail;
use backtrace::Backtrace;
pub(crate) struct ErrorImpl {
inner: Box<Inner<Fail>>,
}
struct Inner<F: ?Sized + Fail> {
backtrace: Backtrace,
pub(crate) failure: F,
}
impl<F: Fail> From<F> for ErrorImpl {
fn from(failure: F) -> ErrorImpl {
let inner: Inner<F> = {
let backtrace = if failure.backtrace().is_none() {
Backtrace::new()
} else { Backtrace::none() };
Inner { failure, backtrace }
};
ErrorImpl { inner: Box::new(inner) }
}
}
impl ErrorImpl {
pub(crate) fn failure(&self) -> &Fail {
&self.inner.failure
}
pub(crate) fn failure_mut(&mut self) -> &mut Fail {
&mut self.inner.failure
}
pub(crate) fn backtrace(&self) -> &Backtrace {
&self.inner.backtrace
}
pub(crate) fn downcast<T: Fail>(self) -> Result<T, ErrorImpl> {
if self.failure().__private_get_type_id__() == TypeId::of::<T>() {
let ErrorImpl { inner } = self;
let casted = unsafe { Box::from_raw(Box::into_raw(inner) as *mut Inner<T>) };
let Inner { backtrace:_, failure } = *casted;
Ok(failure)
} else {
Err(self)
}
}
}