bevy/crates/bevy_reflect/src/impls/smallvec.rs
MrGVSV acbee7795d bevy_reflect: Reflect arrays (#4701)
# Objective

> ℹ️ **Note**: This is a rebased version of #2383. A large portion of it has not been touched (only a few minor changes) so that any additional discussion may happen here. All credit should go to @NathanSWard for their work on the original PR.

- Currently reflection is not supported for arrays.
- Fixes #1213

## Solution

* Implement reflection for arrays via the `Array` trait.
* Note, `Array` is different from `List` in the way that you cannot push elements onto an array as they are statically sized.
* Now `List` is defined as a sub-trait of `Array`.

---

## Changelog

* Added the `Array` reflection trait
* Allows arrays up to length 32 to be reflected via the `Array` trait

## Migration Guide

* The `List` trait now has the `Array` supertrait. This means that `clone_dynamic` will need to specify which version to use:
  ```rust
  // Before
  let cloned = my_list.clone_dynamic();
  // After
  let cloned = List::clone_dynamic(&my_list);
  ```
* All implementers of `List` will now need to implement `Array` (this mostly involves moving the existing methods to the `Array` impl)

Co-authored-by: NathanW <nathansward@comcast.net>
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
2022-05-13 01:13:30 +00:00

131 lines
3.1 KiB
Rust

use smallvec::SmallVec;
use std::any::Any;
use crate::{
serde::Serializable, Array, ArrayIter, FromReflect, List, Reflect, ReflectMut, ReflectRef,
};
impl<T: smallvec::Array + Send + Sync + 'static> Array for SmallVec<T>
where
T::Item: FromReflect + Clone,
{
fn get(&self, index: usize) -> Option<&dyn Reflect> {
if index < SmallVec::len(self) {
Some(&self[index] as &dyn Reflect)
} else {
None
}
}
fn get_mut(&mut self, index: usize) -> Option<&mut dyn Reflect> {
if index < SmallVec::len(self) {
Some(&mut self[index] as &mut dyn Reflect)
} else {
None
}
}
fn len(&self) -> usize {
<SmallVec<T>>::len(self)
}
fn iter(&self) -> ArrayIter {
ArrayIter {
array: self,
index: 0,
}
}
}
impl<T: smallvec::Array + Send + Sync + 'static> List for SmallVec<T>
where
T::Item: FromReflect + Clone,
{
fn push(&mut self, value: Box<dyn Reflect>) {
let value = value.take::<T::Item>().unwrap_or_else(|value| {
<T as smallvec::Array>::Item::from_reflect(&*value).unwrap_or_else(|| {
panic!(
"Attempted to push invalid value of type {}.",
value.type_name()
)
})
});
SmallVec::push(self, value);
}
}
// SAFE: any and any_mut both return self
unsafe impl<T: smallvec::Array + Send + Sync + 'static> Reflect for SmallVec<T>
where
T::Item: FromReflect + Clone,
{
fn type_name(&self) -> &str {
std::any::type_name::<Self>()
}
fn any(&self) -> &dyn Any {
self
}
fn any_mut(&mut self) -> &mut dyn Any {
self
}
fn as_reflect(&self) -> &dyn Reflect {
self
}
fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
self
}
fn apply(&mut self, value: &dyn Reflect) {
crate::list_apply(self, value);
}
fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>> {
*self = value.take()?;
Ok(())
}
fn reflect_ref(&self) -> ReflectRef {
ReflectRef::List(self)
}
fn reflect_mut(&mut self) -> ReflectMut {
ReflectMut::List(self)
}
fn clone_value(&self) -> Box<dyn Reflect> {
Box::new(List::clone_dynamic(self))
}
fn reflect_hash(&self) -> Option<u64> {
None
}
fn reflect_partial_eq(&self, value: &dyn Reflect) -> Option<bool> {
crate::list_partial_eq(self, value)
}
fn serializable(&self) -> Option<Serializable> {
None
}
}
impl<T: smallvec::Array + Send + Sync + 'static> FromReflect for SmallVec<T>
where
T::Item: FromReflect + Clone,
{
fn from_reflect(reflect: &dyn Reflect) -> Option<Self> {
if let ReflectRef::List(ref_list) = reflect.reflect_ref() {
let mut new_list = Self::with_capacity(ref_list.len());
for field in ref_list.iter() {
new_list.push(<T as smallvec::Array>::Item::from_reflect(field)?);
}
Some(new_list)
} else {
None
}
}
}