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#[derive(Clone)]
pub(crate) struct AnyValue {
inner: std::sync::Arc<dyn std::any::Any + Send + Sync + 'static>,
// While we can extract `TypeId` from `inner`, the debug repr is of a number, so let's track
// the type_name in debug builds.
id: AnyValueId,
}
impl AnyValue {
pub(crate) fn new<V: std::any::Any + Clone + Send + Sync + 'static>(inner: V) -> Self {
let id = AnyValueId::of::<V>();
let inner = std::sync::Arc::new(inner);
Self { inner, id }
}
pub(crate) fn downcast_ref<T: std::any::Any + Clone + Send + Sync + 'static>(
&self,
) -> Option<&T> {
self.inner.downcast_ref::<T>()
}
pub(crate) fn downcast_into<T: std::any::Any + Clone + Send + Sync>(self) -> Result<T, Self> {
let id = self.id;
let value =
ok!(std::sync::Arc::downcast::<T>(self.inner).map_err(|inner| Self { inner, id }));
let value = std::sync::Arc::try_unwrap(value).unwrap_or_else(|arc| (*arc).clone());
Ok(value)
}
pub(crate) fn type_id(&self) -> AnyValueId {
self.id
}
}
impl std::fmt::Debug for AnyValue {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
f.debug_struct("AnyValue").field("inner", &self.id).finish()
}
}
#[derive(Copy, Clone)]
pub struct AnyValueId {
type_id: std::any::TypeId,
#[cfg(debug_assertions)]
type_name: &'static str,
}
impl AnyValueId {
pub(crate) fn of<A: ?Sized + 'static>() -> Self {
Self {
type_id: std::any::TypeId::of::<A>(),
#[cfg(debug_assertions)]
type_name: std::any::type_name::<A>(),
}
}
}
impl PartialEq for AnyValueId {
fn eq(&self, other: &Self) -> bool {
self.type_id == other.type_id
}
}
impl Eq for AnyValueId {}
impl PartialOrd for AnyValueId {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
Some(self.cmp(other))
}
}
impl PartialEq<std::any::TypeId> for AnyValueId {
fn eq(&self, other: &std::any::TypeId) -> bool {
self.type_id == *other
}
}
impl Ord for AnyValueId {
fn cmp(&self, other: &Self) -> std::cmp::Ordering {
self.type_id.cmp(&other.type_id)
}
}
impl std::hash::Hash for AnyValueId {
fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
self.type_id.hash(state);
}
}
impl std::fmt::Debug for AnyValueId {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
#[cfg(not(debug_assertions))]
{
self.type_id.fmt(f)
}
#[cfg(debug_assertions)]
{
f.debug_struct(self.type_name).finish()
}
}
}
impl<'a, A: ?Sized + 'static> From<&'a A> for AnyValueId {
fn from(_: &'a A) -> Self {
Self::of::<A>()
}
}
#[cfg(test)]
mod test {
#[test]
#[cfg(debug_assertions)]
fn debug_impl() {
use super::*;
assert_eq!(format!("{:?}", AnyValue::new(5)), "AnyValue { inner: i32 }");
}
#[test]
fn eq_to_type_id() {
use super::*;
let any_value_id = AnyValueId::of::<i32>();
let type_id = std::any::TypeId::of::<i32>();
assert_eq!(any_value_id, type_id);
}
}