# Objective
Fixes#8596
## Solution
Change interface of the trait Map. Adjust implementations of this trait
---
## Changelog
### Changed
- Interface of Map trait
### Added
- `Map::get_at_mut`
## Migration Guide
Every implementor of Map trait would need to implement `get_at_mut`.
Which, judging by changes in this PR, should be fairly trivial.
# Objective
Right now it's impossible to construct a MapIter outside of the
bevy_reflect crate, making it impossible to implement the Map trait for
custom map types.
## Solution
Addition of a pub constructor to MapIter.
# Objective
When using `FromReflect`, fields can be optionally left out if they are
marked with `#[reflect(default)]`. This is very handy for working with
serialized data as giant structs only need to list a subset of defined
fields in order to be constructed.
<details>
<summary>Example</summary>
Take the following struct:
```rust
#[derive(Reflect, FromReflect)]
struct Foo {
#[reflect(default)]
a: usize,
#[reflect(default)]
b: usize,
#[reflect(default)]
c: usize,
#[reflect(default)]
d: usize,
}
```
Since all the fields are default-able, we can successfully call
`FromReflect` on deserialized data like:
```rust
(
"foo::Foo": (
// Only set `b` and default the rest
b: 123
)
)
```
</details>
Unfortunately, this does not work with fields in enum variants. Marking
a variant field as `#[reflect(default)]` does nothing when calling
`FromReflect`.
## Solution
Allow enum variant fields to define a default value using
`#[reflect(default)]`.
### `#[reflect(Default)]`
One thing that structs and tuple structs can do is use their `Default`
implementation when calling `FromReflect`. Adding `#[reflect(Default)]`
to the struct or tuple struct both registers `ReflectDefault` and alters
the `FromReflect` implementation to use `Default` to generate any
missing fields.
This works well enough for structs and tuple structs, but for enums it's
not as simple. Since the `Default` implementation for an enum only
covers a single variant, it's not as intuitive as to what the behavior
will be. And (imo) it feels weird that we would be able to specify
default values in this way for one variant but not the others.
Because of this, I chose to not implement that behavior here. However,
I'm open to adding it in if anyone feels otherwise.
---
## Changelog
- Allow enum variant fields to define a default value using
`#[reflect(default)]`
# Objective
- Add Reflect and FromReflect for AssetPath
- Fixes#8458
## Solution
- Straightforward derive of `Reflect` and `FromReflect` for `AssetPath`
- Implement `Reflect` and `FromReflect` for `Cow<'static, Path>` as to
satisfy the 'static lifetime requierments of bevy_reflect.
Implementation is a direct copy of that for `Cow<'static, str>` so maybe
it begs the question that was already asked in #7429 - maybe it would be
benefitial to write a general implementation for `Reflect` for
`Cow<'static, T>`.
# Objective
> This PR is based on discussion from #6601
The Dynamic types (e.g. `DynamicStruct`, `DynamicList`, etc.) act as
both:
1. Dynamic containers which may hold any arbitrary data
2. Proxy types which may represent any other type
Currently, the only way we can represent the proxy-ness of a Dynamic is
by giving it a name.
```rust
// This is just a dynamic container
let mut data = DynamicStruct::default();
// This is a "proxy"
data.set_name(std::any::type_name::<Foo>());
```
This type name is the only way we check that the given Dynamic is a
proxy of some other type. When we need to "assert the type" of a `dyn
Reflect`, we call `Reflect::type_name` on it. However, because we're
only using a string to denote the type, we run into a few gotchas and
limitations.
For example, hashing a Dynamic proxy may work differently than the type
it proxies:
```rust
#[derive(Reflect, Hash)]
#[reflect(Hash)]
struct Foo(i32);
let concrete = Foo(123);
let dynamic = concrete.clone_dynamic();
let concrete_hash = concrete.reflect_hash();
let dynamic_hash = dynamic.reflect_hash();
// The hashes are not equal because `concrete` uses its own `Hash` impl
// while `dynamic` uses a reflection-based hashing algorithm
assert_ne!(concrete_hash, dynamic_hash);
```
Because the Dynamic proxy only knows about the name of the type, it's
unaware of any other information about it. This means it also differs on
`Reflect::reflect_partial_eq`, and may include ignored or skipped fields
in places the concrete type wouldn't.
## Solution
Rather than having Dynamics pass along just the type name of proxied
types, we can instead have them pass around the `TypeInfo`.
Now all Dynamic types contain an `Option<&'static TypeInfo>` rather than
a `String`:
```diff
pub struct DynamicTupleStruct {
- type_name: String,
+ represented_type: Option<&'static TypeInfo>,
fields: Vec<Box<dyn Reflect>>,
}
```
By changing `Reflect::get_type_info` to
`Reflect::represented_type_info`, hopefully we make this behavior a
little clearer. And to account for `None` values on these dynamic types,
`Reflect::represented_type_info` now returns `Option<&'static
TypeInfo>`.
```rust
let mut data = DynamicTupleStruct::default();
// Not proxying any specific type
assert!(dyn_tuple_struct.represented_type_info().is_none());
let type_info = <Foo as Typed>::type_info();
dyn_tuple_struct.set_represented_type(Some(type_info));
// Alternatively:
// let dyn_tuple_struct = foo.clone_dynamic();
// Now we're proxying `Foo`
assert!(dyn_tuple_struct.represented_type_info().is_some());
```
This means that we can have full access to all the static type
information for the proxied type. Future work would include
transitioning more static type information (trait impls, attributes,
etc.) over to the `TypeInfo` so it can actually be utilized by Dynamic
proxies.
### Alternatives & Rationale
> **Note**
> These alternatives were written when this PR was first made using a
`Proxy` trait. This trait has since been removed.
<details>
<summary>View</summary>
#### Alternative: The `Proxy<T>` Approach
I had considered adding something like a `Proxy<T>` type where `T` would
be the Dynamic and would contain the proxied type information.
This was nice in that it allows us to explicitly determine whether
something is a proxy or not at a type level. `Proxy<DynamicStruct>`
proxies a struct. Makes sense.
The reason I didn't go with this approach is because (1) tuples, (2)
complexity, and (3) `PartialReflect`.
The `DynamicTuple` struct allows us to represent tuples at runtime. It
also allows us to do something you normally can't with tuples: add new
fields. Because of this, adding a field immediately invalidates the
proxy (e.g. our info for `(i32, i32)` doesn't apply to `(i32, i32,
NewField)`). By going with this PR's approach, we can just remove the
type info on `DynamicTuple` when that happens. However, with the
`Proxy<T>` approach, it becomes difficult to represent this behavior—
we'd have to completely control how we access data for `T` for each `T`.
Secondly, it introduces some added complexities (aside from the manual
impls for each `T`). Does `Proxy<T>` impl `Reflect`? Likely yes, if we
want to represent it as `dyn Reflect`. What `TypeInfo` do we give it?
How would we forward reflection methods to the inner type (remember, we
don't have specialization)? How do we separate this from Dynamic types?
And finally, how do all this in a way that's both logical and intuitive
for users?
Lastly, introducing a `Proxy` trait rather than a `Proxy<T>` struct is
actually more inline with the [Unique Reflect
RFC](https://github.com/bevyengine/rfcs/pull/56). In a way, the `Proxy`
trait is really one part of the `PartialReflect` trait introduced in
that RFC (it's technically not in that RFC but it fits well with it),
where the `PartialReflect` serves as a way for proxies to work _like_
concrete types without having full access to everything a concrete
`Reflect` type can do. This would help bridge the gap between the
current state of the crate and the implementation of that RFC.
All that said, this is still a viable solution. If the community
believes this is the better path forward, then we can do that instead.
These were just my reasons for not initially going with it in this PR.
#### Alternative: The Type Registry Approach
The `Proxy` trait is great and all, but how does it solve the original
problem? Well, it doesn't— yet!
The goal would be to start moving information from the derive macro and
its attributes to the generated `TypeInfo` since these are known
statically and shouldn't change. For example, adding `ignored: bool` to
`[Un]NamedField` or a list of impls.
However, there is another way of storing this information. This is, of
course, one of the uses of the `TypeRegistry`. If we're worried about
Dynamic proxies not aligning with their concrete counterparts, we could
move more type information to the registry and require its usage.
For example, we could replace `Reflect::reflect_hash(&self)` with
`Reflect::reflect_hash(&self, registry: &TypeRegistry)`.
That's not the _worst_ thing in the world, but it is an ergonomics loss.
Additionally, other attributes may have their own requirements, further
restricting what's possible without the registry. The `Reflect::apply`
method will require the registry as well now. Why? Well because the
`map_apply` function used for the `Reflect::apply` impls on `Map` types
depends on `Map::insert_boxed`, which (at least for `DynamicMap`)
requires `Reflect::reflect_hash`. The same would apply when adding
support for reflection-based diffing, which will require
`Reflect::reflect_partial_eq`.
Again, this is a totally viable alternative. I just chose not to go with
it for the reasons above. If we want to go with it, then we can close
this PR and we can pursue this alternative instead.
#### Downsides
Just to highlight a quick potential downside (likely needs more
investigation): retrieving the `TypeInfo` requires acquiring a lock on
the `GenericTypeInfoCell` used by the `Typed` impls for generic types
(non-generic types use a `OnceBox which should be faster). I am not sure
how much of a performance hit that is and will need to run some
benchmarks to compare against.
</details>
### Open Questions
1. Should we use `Cow<'static, TypeInfo>` instead? I think that might be
easier for modding? Perhaps, in that case, we need to update
`Typed::type_info` and friends as well?
2. Are the alternatives better than the approach this PR takes? Are
there other alternatives?
---
## Changelog
### Changed
- `Reflect::get_type_info` has been renamed to
`Reflect::represented_type_info`
- This method now returns `Option<&'static TypeInfo>` rather than just
`&'static TypeInfo`
### Added
- Added `Reflect::is_dynamic` method to indicate when a type is dynamic
- Added a `set_represented_type` method on all dynamic types
### Removed
- Removed `TypeInfo::Dynamic` (use `Reflect::is_dynamic` instead)
- Removed `Typed` impls for all dynamic types
## Migration Guide
- The Dynamic types no longer take a string type name. Instead, they
require a static reference to `TypeInfo`:
```rust
#[derive(Reflect)]
struct MyTupleStruct(f32, f32);
let mut dyn_tuple_struct = DynamicTupleStruct::default();
dyn_tuple_struct.insert(1.23_f32);
dyn_tuple_struct.insert(3.21_f32);
// BEFORE:
let type_name = std::any::type_name::<MyTupleStruct>();
dyn_tuple_struct.set_name(type_name);
// AFTER:
let type_info = <MyTupleStruct as Typed>::type_info();
dyn_tuple_struct.set_represented_type(Some(type_info));
```
- `Reflect::get_type_info` has been renamed to
`Reflect::represented_type_info` and now also returns an
`Option<&'static TypeInfo>` (instead of just `&'static TypeInfo`):
```rust
// BEFORE:
let info: &'static TypeInfo = value.get_type_info();
// AFTER:
let info: &'static TypeInfo = value.represented_type_info().unwrap();
```
- `TypeInfo::Dynamic` and `DynamicInfo` has been removed. Use
`Reflect::is_dynamic` instead:
```rust
// BEFORE:
if matches!(value.get_type_info(), TypeInfo::Dynamic) {
// ...
}
// AFTER:
if value.is_dynamic() {
// ...
}
```
---------
Co-authored-by: radiish <cb.setho@gmail.com>
# Objective
Considering that `FromReflect` is a very common trait to derive, it
would make sense to include `ReflectFromReflect` in the `bevy_reflect`
prelude so users don't need to import it separately.
## Solution
Add `ReflectFromReflect` to the prelude.
Links in the api docs are nice. I noticed that there were several places
where structs / functions and other things were referenced in the docs,
but weren't linked. I added the links where possible / logical.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François <mockersf@gmail.com>
# Objective
- Fix the issue described in #8183: Box<dyn Reflect> structs with a
hashmap in them will panic when clone_value is called on it
- Fixes: #8183
## Solution
- Updates the implementation of Reflect for Hashmaps to make clone_value
call from_reflect on the key before inserting it into the new struct
Fixes issue mentioned in PR #8285.
_Note: By mistake, this is currently dependent on #8285_
# Objective
Ensure consistency in the spelling of the documentation.
Exceptions:
`crates/bevy_mikktspace/src/generated.rs` - Has not been changed from
licence to license as it is part of a licensing agreement.
Maybe for further consistency,
https://github.com/bevyengine/bevy-website should also be given a look.
## Solution
### Changed the spelling of the current words (UK/CN/AU -> US) :
cancelled -> canceled (Breaking API changes in #8285)
behaviour -> behavior (Breaking API changes in #8285)
neighbour -> neighbor
grey -> gray
recognise -> recognize
centre -> center
metres -> meters
colour -> color
### ~~Update [`engine_style_guide.md`]~~ Moved to #8324
---
## Changelog
Changed UK spellings in documentation to US
## Migration Guide
Non-breaking changes*
\* If merged after #8285
# Objective
The clippy lint `type_complexity` is known not to play well with bevy.
It frequently triggers when writing complex queries, and taking the
lint's advice of using a type alias almost always just obfuscates the
code with no benefit. Because of this, this lint is currently ignored in
CI, but unfortunately it still shows up when viewing bevy code in an
IDE.
As someone who's made a fair amount of pull requests to this repo, I
will say that this issue has been a consistent thorn in my side. Since
bevy code is filled with spurious, ignorable warnings, it can be very
difficult to spot the *real* warnings that must be fixed -- most of the
time I just ignore all warnings, only to later find out that one of them
was real after I'm done when CI runs.
## Solution
Suppress this lint in all bevy crates. This was previously attempted in
#7050, but the review process ended up making it more complicated than
it needs to be and landed on a subpar solution.
The discussion in https://github.com/rust-lang/rust-clippy/pull/10571
explores some better long-term solutions to this problem. Since there is
no timeline on when these solutions may land, we should resolve this
issue in the meantime by locally suppressing these lints.
### Unresolved issues
Currently, these lints are not suppressed in our examples, since that
would require suppressing the lint in every single source file. They are
still ignored in CI.
# Objective
Fix typo in bevy_reflect README: `MyType` is a struct and not a trait,
so `&dyn MyType` is incorrect.
## Solution
Replace `&dyn MyType` with `&dyn DoThing`
# Objective
Fixes#7989
Based on #7991 by @CoffeeVampir3
## Solution
There were three parts to this issue:
1. `extend_where_clause` did not account for the optionality of a where
clause's trailing comma
```rust
// OKAY
struct Foo<T> where T: Asset, {/* ... */}
// ERROR
struct Foo<T> where T: Asset {/* ... */}
```
2. `FromReflect` derive logic was not actively using
`extend_where_clause` which led to some inconsistencies (enums weren't
adding _any_ additional bounds even)
3. Using `extend_where_clause` in the `FromReflect` derive logic meant
we had to optionally add `Default` bounds to ignored fields iff the
entire item itself was not already `Default` (otherwise the definition
for `Handle<T>` wouldn't compile since `HandleType` doesn't impl
`Default` but `Handle<T>` itself does)
---
## Changelog
- Fixed issue where a missing trailing comma could break the reflection
derives
# Objective
- Update `glam` to the latest version.
## Solution
- Update `glam` to version `0.23`.
Since the breaking change in `glam` only affects the `scalar-math` feature, this should cause no issues.
# Objective
Implement `Reflect` for `std::collections::HashMap<K, V, S>` as well as `hashbrown::HashMap<K, V, S>` rather than just for `hashbrown::HashMap<K, V, RandomState>`. Fixes#7739.
## Solution
Rather than implementing on `HashMap<K, V>` I instead implemented most of the related traits on `HashMap<K, V, S> where S: BuildHasher + Send + Sync + 'static` and then `FromReflect` also needs the extra bound `S: Default` because it needs to use `with_capacity_and_hasher` so needs to be able to generate a default hasher.
As the API of `hashbrown::HashMap` is identical to `collections::HashMap` making them both work just required creating an `impl_reflect_for_hashmap` macro like the `impl_reflect_for_veclike` above and then applying this to both HashMaps.
---
## Changelog
`std::collections::HashMap` can now be reflected. Also more `State` generics than just `RandomState` can now be reflected for both `hashbrown::HashMap` and `collections::HashMap`
# Objective
There were a couple primitive types missing from the default `TypeRegistry` constructor.
## Solution
Added the missing registrations for `char` and `String`.
# Objective
`cargo run -p ci` is currently failing locally for me.
```
error: variables can be used directly in the `format!` string
--> crates/bevy_reflect/bevy_reflect_derive/src/type_uuid.rs:106:69
|
106 | let uuid = Uuid::parse_str(&uuid).map_err(|err| input.error(format!("{}", err)))?;
```
It's not clear to me why CI/clippy didn't pick this up in #6633.
# Objective
`bevy_reflect` can be a moderately complex crate to try and understand. It has many moving parts, a handful of gotchas, and a few subtle contracts that aren't immediately obvious to users and even other contributors.
The current README does an okay job demonstrating how the crate can be used. However, the crate's actual documentation should give a better overview of the crate, its inner-workings, and show some of its own examples.
## Solution
Added crate-level documentation that attempts to summarize the main parts of `bevy_reflect` into small sections.
This PR also updates the documentation for:
- `Reflect`
- `FromReflect`
- The reflection subtraits
- Other important types and traits
- The reflection macros (including the derive macros)
- Crate features
### Open Questions
1. ~~Should I update the docs for the Dynamic types? I was originally going to, but I'm getting a little concerned about the size of this PR 😅~~ Decided to not do this in this PR. It'll be better served from its own PR.
2. Should derive macro documentation be moved to the trait itself? This could improve visibility and allow for better doc links, but could also clutter up the trait's documentation (as well as not being on the actual derive macro's documentation).
### TODO
- [ ] ~~Document Dynamic types (?)~~ I think this should be done in a separate PR.
- [x] Document crate features
- [x] Update docs for `GetTypeRegistration`
- [x] Update docs for `TypeRegistration`
- [x] Update docs for `derive_from_reflect`
- [x] Document `reflect_trait`
- [x] Document `impl_reflect_value`
- [x] Document `impl_from_reflect_value`
---
## Changelog
- Updated documentation across the `bevy_reflect` crate
- Removed `#[module]` helper attribute for `Reflect` derives (this is not currently used)
## Migration Guide
- Removed `#[module]` helper attribute for `Reflect` derives. If your code is relying on this attribute, please replace it with either `#[reflect]` or `#[reflect_value]` (dependent on use-case).
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
- bevy_ggrs uses `reflect_hash` in order to produce checksums for its world snapshots. These checksums are sent between clients in order to detect desyncronization.
- However, since we currently use `async::AHasher` with the `std` feature, this means that hashes will always be different for different peers, even if the state is identical.
- This means bevy_ggrs needs a way to get a deterministic (fixed) hash.
## Solution
- ~~Add a feature to use `bevy_utils::FixedState` for the hasher used by bevy_reflect.~~
- Always use `bevy_utils::FixedState` for initializing the bevy_reflect hasher.
---
## Changelog
- bevy_reflect now uses a fixed state for its hasher, which means the output of `Reflect::reflect_hash` is now deterministic across processes.
# Objective
- Fixes#5432
- Fixes#6680
## Solution
- move code responsible for generating the `impl TypeUuid` from `type_uuid_derive` into a new function, `gen_impl_type_uuid`.
- this allows the new proc macro, `impl_type_uuid`, to call the code for generation.
- added struct `TypeUuidDef` and implemented `syn::Parse` to allow parsing of the input for the new macro.
- finally, used the new macro `impl_type_uuid` to implement `TypeUuid` for the standard library (in `crates/bevy_reflect/src/type_uuid_impl.rs`).
- fixes#6680 by doing a wrapping add of the param's index to its `TYPE_UUID`
Co-authored-by: dis-da-moe <84386186+dis-da-moe@users.noreply.github.com>
# Objective
Resolves#7121
## Solution
Decouples `List` and `Array` by removing `Array` as a supertrait of `List`. Additionally, similar methods from `Array` have been added to `List` so that their usages can remain largely unchanged.
#### Possible Alternatives
##### `Sequence`
My guess for why we originally made `List` a subtrait of `Array` is that they share a lot of common operations. We could potentially move these overlapping methods to a `Sequence` (name taken from #7059) trait and make that a supertrait of both. This would allow functions to contain logic that simply operates on a sequence rather than "list vs array".
However, this means that we'd need to add methods for converting to a `dyn Sequence`. It also might be confusing since we wouldn't add a `ReflectRef::Sequence` or anything like that. Is such a trait worth adding (either in this PR or a followup one)?
---
## Changelog
- Removed `Array` as supertrait of `List`
- Added methods to `List` that were previously provided by `Array`
## Migration Guide
The `List` trait is no longer dependent on `Array`. Implementors of `List` can remove the `Array` impl and move its methods into the `List` impl (with only a couple tweaks).
```rust
// BEFORE
impl Array for Foo {
fn get(&self, index: usize) -> Option<&dyn Reflect> {/* ... */}
fn get_mut(&mut self, index: usize) -> Option<&mut dyn Reflect> {/* ... */}
fn len(&self) -> usize {/* ... */}
fn is_empty(&self) -> bool {/* ... */}
fn iter(&self) -> ArrayIter {/* ... */}
fn drain(self: Box<Self>) -> Vec<Box<dyn Reflect>> {/* ... */}
fn clone_dynamic(&self) -> DynamicArray {/* ... */}
}
impl List for Foo {
fn insert(&mut self, index: usize, element: Box<dyn Reflect>) {/* ... */}
fn remove(&mut self, index: usize) -> Box<dyn Reflect> {/* ... */}
fn push(&mut self, value: Box<dyn Reflect>) {/* ... */}
fn pop(&mut self) -> Option<Box<dyn Reflect>> {/* ... */}
fn clone_dynamic(&self) -> DynamicList {/* ... */}
}
// AFTER
impl List for Foo {
fn get(&self, index: usize) -> Option<&dyn Reflect> {/* ... */}
fn get_mut(&mut self, index: usize) -> Option<&mut dyn Reflect> {/* ... */}
fn insert(&mut self, index: usize, element: Box<dyn Reflect>) {/* ... */}
fn remove(&mut self, index: usize) -> Box<dyn Reflect> {/* ... */}
fn push(&mut self, value: Box<dyn Reflect>) {/* ... */}
fn pop(&mut self) -> Option<Box<dyn Reflect>> {/* ... */}
fn len(&self) -> usize {/* ... */}
fn is_empty(&self) -> bool {/* ... */}
fn iter(&self) -> ListIter {/* ... */}
fn drain(self: Box<Self>) -> Vec<Box<dyn Reflect>> {/* ... */}
fn clone_dynamic(&self) -> DynamicList {/* ... */}
}
```
Some other small tweaks that will need to be made include:
- Use `ListIter` for `List::iter` instead of `ArrayIter` (the return type from `Array::iter`)
- Replace `array_hash` with `list_hash` in `Reflect::reflect_hash` for implementors of `List`
# Objective
Currently the `GetPath` documentation suggests it can be used with `Tuple` types (reflected tuples). However, this is not currently the case.
## Solution
Add reflection path support for `Tuple` types.
---
## Changelog
- Add reflection path support for `Tuple` types
Implementing GetTypeRegistration in macro impl_reflect_for_veclike! had typos!
It only implement GetTypeRegistration for Vec<T>, but not for VecDeque<T>.
This will cause serialization and deserialization failure.
# Objective
- Fixes#7430.
## Solution
- Changed fields of `ArrayIter` to be private.
- Add a constructor `new` to `ArrayIter`.
- Replace normal struct creation with `new`.
---
## Changelog
- Add a constructor `new` to `ArrayIter`.
Co-authored-by: Elbert Ronnie <103196773+elbertronnie@users.noreply.github.com>
# Objective
I recently had an issue, where I have a struct:
```
struct Property {
inner: T
}
```
that I use as a wrapper for internal purposes.
I don't want to update my struct definition to
```
struct Property<T: Reflect>{
inner: T
}
```
because I still want to be able to build `Property<T>` for types `T` that are not `Reflect`. (and also because I don't want to update my whole code base with `<T: Reflect>` bounds)
I still wanted to have reflection on it (for `bevy_inspector_egui`), but adding `derive(Reflect)` fails with the error:
`T cannot be sent between threads safely. T needs to implement Sync.`
I believe that `bevy_reflect` should adopt the model of other derives in the case of generics, which is to add the `Reflect` implementation only if the generics also implement `Reflect`. (That is the behaviour of other macros such as `derive(Clone)` or `derive(Debug)`.
It's also the current behavior of `derive(FromReflect)`.
Basically doing something like:
```
impl<T> Reflect for Foo<T>
where T: Reflect
```
## Solution
- I updated the derive macros for `Structs` and `TupleStructs` to add extra `where` bounds.
- Every type that is reflected will need a `T: Reflect` bound
- Ignored types will need a `T: 'static + Send + Sync` bound. Here's the reason. For cases like this:
```
#[derive(Reflect)]
struct Foo<T, U>{
a: T
#[reflect(ignore)]
b: U
}
```
I had to add the bound `'static + Send + Sync` to ignored generics like `U`.
The reason is that we want `Foo<T, U>` to be `Reflect: 'static + Send + Sync`, so `Foo<T, U>` must be able to implement those auto-traits. `Foo<T, U>` will only implement those auto-traits if every generic type implements them, including ignored types.
This means that the previously compile-fail case now compiles:
```
#[derive(Reflect)]
struct Foo<'a> {
#[reflect(ignore)]
value: &'a str,
}
```
But `Foo<'a>` will only be useable in the cases where `'a: 'static` and panic if we don't have `'a: 'static`, which is what we want (nice bonus from this PR ;) )
---
## Changelog
> This section is optional. If this was a trivial fix, or has no externally-visible impact, you can delete this section.
### Added
Possibility to add `derive(Reflect)` to structs and enums that contain generic types, like so:
```
#[derive(Reflect)]
struct Foo<T>{
a: T
}
```
Reflection will only be available if the generic type T also implements `Reflect`.
(previously, this would just return a compiler error)
# Objective
I found several words in code and docs are incorrect. This should be fixed.
## Solution
- Fix several minor typos
Co-authored-by: Chris Ohk <utilforever@gmail.com>
# Objective
> ℹ️ **This is an adoption of #4081 by @james7132**
Fixes#4080.
Provide a way to pre-parse reflection paths so as to avoid having to parse at each call to `GetPath::path` (or similar method).
## Solution
Adds the `ParsedPath` struct (named `FieldPath` in the original PR) that parses and caches the sequence of accesses to a reflected element. This is functionally similar to the `GetPath` trait, but removes the need to parse an unchanged path more than once.
### Additional Changes
Included in this PR from the original is cleaner code as well as the introduction of a new pathing operation: field access by index. This allows struct and struct variant fields to be accessed in a more performant (albeit more fragile) way if needed. This operation is faster due to not having to perform string matching. As an example, if we wanted the third field on a struct, we'd write `#2`—where `#` denotes indexed access and `2` denotes the desired field index.
This PR also contains improved documentation for `GetPath` and friends, including renaming some of the methods to be more clear to the end-user with a reduced risk of getting them mixed up.
### Future Work
There are a few things that could be done as a separate PR (order doesn't matter— they could be followup PRs or done in parallel). These are:
- [x] ~~Add support for `Tuple`. Currently, we hint that they work but they do not.~~ See #7324
- [ ] Cleanup `ReflectPathError`. I think it would be nicer to give `ReflectPathError` two variants: `ReflectPathError::ParseError` and `ReflectPathError::AccessError`, with all current variants placed within one of those two. It's not obvious when one might expect to receive one type of error over the other, so we can help by explicitly categorizing them.
---
## Changelog
- Cleaned up `GetPath` logic
- Added `ParsedPath` for cached reflection paths
- Added new reflection path syntax: struct field access by index (example syntax: `foo#1`)
- Renamed methods on `GetPath`:
- `path` -> `reflect_path`
- `path_mut` -> `reflect_path_mut`
- `get_path` -> `path`
- `get_path_mut` -> `path_mut`
## Migration Guide
`GetPath` methods have been renamed according to the following:
- `path` -> `reflect_path`
- `path_mut` -> `reflect_path_mut`
- `get_path` -> `path`
- `get_path_mut` -> `path_mut`
Co-authored-by: Gino Valente <gino.valente.code@gmail.com>
# Objective
Enums are now reflectable, but are not accessible via reflection paths.
This would allow us to do things like:
```rust
#[derive(Reflect)]
struct MyStruct {
data: MyEnum
}
#[derive(Reflect)]
struct MyEnum {
Foo(u32, u32),
Bar(bool)
}
let x = MyStruct {
data: MyEnum::Foo(123),
};
assert_eq!(*x.get_path::<u32>("data.1").unwrap(), 123);
```
## Solution
Added support for enums in reflection paths.
##### Note
This uses a simple approach of just getting the field with the given accessor. It does not do matching or anything else to ensure the enum is the intended variant. This means that the variant must be known ahead of time or matched outside the reflection path (i.e. path to variant, perform manual match, and continue pathing).
---
## Changelog
- Added support for enums in reflection paths
# Objective
There are times where we want to simply take an owned `dyn Reflect` and cast it to a type `T`.
Currently, this involves doing:
```rust
let value = value.take::<T>().unwrap_or_else(|value| {
T::from_reflect(&*value).unwrap_or_else(|| {
panic!(
"expected value of type {} to convert to type {}.",
value.type_name(),
std::any::type_name::<T>()
)
})
});
```
This is a common operation that could be easily be simplified.
## Solution
Add the `FromReflect::take_from_reflect` method. This first tries to `take` the value, calling `from_reflect` iff that fails.
```rust
let value = T::take_from_reflect(value).unwrap_or_else(|value| {
panic!(
"expected value of type {} to convert to type {}.",
value.type_name(),
std::any::type_name::<T>()
)
});
```
Based on suggestion from @soqb on [Discord](https://discord.com/channels/691052431525675048/1002362493634629796/1041046880316043374).
---
## Changelog
- Add `FromReflect::take_from_reflect` method
# Objective
This a follow-up to #6894, see https://github.com/bevyengine/bevy/pull/6894#discussion_r1045203113
The goal is to avoid cloning any string when getting a `&TypeRegistration` corresponding to a string which is being deserialized. As a bonus code duplication is also reduced.
## Solution
The manual deserialization of a string and lookup into the type registry has been moved into a separate `TypeRegistrationDeserializer` type, which implements `DeserializeSeed` with a `Visitor` that accepts any string with `visit_str`, even ones that may not live longer than that function call.
`BorrowedStr` has been removed since it's no longer used.
---
## Changelog
- The type `TypeRegistrationDeserializer` has been added, which simplifies getting a `&TypeRegistration` while deserializing a string.
# Objective
- Fixes#7061
## Solution
- Add and implement `insert` and `remove` methods for `List`.
---
## Changelog
- Added `insert` and `remove` methods to `List`.
- Changed the `push` and `pop` methods on `List` to have default implementations.
## Migration Guide
- Manual implementors of `List` need to implement the new methods `insert` and `remove` and
consider whether to use the new default implementation of `push` and `pop`.
Co-authored-by: radiish <thesethskigamer@gmail.com>
# Objective
Fixes#6891
## Solution
Replaces deserializing map keys as `&str` with deserializing them as `String`.
This bug seems to occur when using something like `File` or `BufReader` rather than bytes or a string directly (I only tested `File` and `BufReader` for `rmp-serde` and `serde_json`). This might be an issue with other `Read` impls as well (except `&[u8]` it seems).
We already had passing tests for Message Pack but none that use a `File` or `BufReader`. This PR also adds or modifies tests to check for this in the future.
This change was also based on [feedback](https://github.com/bevyengine/bevy/pull/4561#discussion_r957385136) I received in a previous PR.
---
## Changelog
- Fix bug where scene deserialization using certain readers could fail (e.g. `BufReader`, `File`, etc.)
# Objective
This is an adoption of #5792. Fixes#5791.
## Solution
Implemented all the required reflection traits for `VecDeque`, taking from `Vec`'s impls.
---
## Changelog
Added: `std::collections::VecDeque` now implements `Reflect` and all relevant traits.
Co-authored-by: james7132 <contact@jamessliu.com>
# Objective
Resolves#4597 (based on the work from #6056 and a refresh of #4147)
When using reflection, we may often end up in a scenario where we have a Dynamic representing a certain type. Unfortunately, we can't just call `MyType::from_reflect` as we do not have knowledge of the concrete type (`MyType`) at runtime.
Such scenarios happen when we call `Reflect::clone_value`, use the reflection deserializers, or create the Dynamic type ourselves.
## Solution
Add a `ReflectFromReflect` type data struct.
This struct allows us to easily convert Dynamic representations of our types into their respective concrete instances.
```rust
#[derive(Reflect, FromReflect)]
#[reflect(FromReflect)] // <- Register `ReflectFromReflect`
struct MyStruct(String);
let type_id = TypeId::of::<MyStruct>();
// Register our type
let mut registry = TypeRegistry::default();
registry.register::<MyStruct>();
// Create a concrete instance
let my_struct = MyStruct("Hello world".to_string());
// `Reflect::clone_value` will generate a `DynamicTupleStruct` for tuple struct types
let dynamic_value: Box<dyn Reflect> = my_struct.clone_value();
assert!(!dynamic_value.is::<MyStruct>());
// Get the `ReflectFromReflect` type data from the registry
let rfr: &ReflectFromReflect = registry
.get_type_data::<ReflectFromReflect>(type_id)
.unwrap();
// Call `FromReflect::from_reflect` on our Dynamic value
let concrete_value: Box<dyn Reflect> = rfr.from_reflect(&dynamic_value);
assert!(concrete_value.is::<MyStruct>());
```
### Why this PR?
###### Why now?
The three main reasons I closed#4147 were that:
1. Registering `ReflectFromReflect` is clunky (deriving `FromReflect` *and* registering `ReflectFromReflect`)
2. The ecosystem and Bevy itself didn't seem to pay much attention to deriving `FromReflect`
3. I didn't see a lot of desire from the community for such a feature
However, as time has passed it seems 2 and 3 are not really true anymore. Bevy is internally adding lots more `FromReflect` derives, which should make this feature all the more useful. Additionally, I have seen a growing number of people look for something like `ReflectFromReflect`.
I think 1 is still an issue, but not a horrible one. Plus it could be made much, much better using #6056. And I think splitting this feature out of #6056 could lead to #6056 being adopted sooner (or at least make the need more clear to users).
###### Why not just re-open #4147?
The main reason is so that this PR can garner more attention than simply re-opening the old one. This helps bring fresh eyes to the PR for potentially more perspectives/reviews.
---
## Changelog
* Added `ReflectFromReflect`
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
Fixes#6866.
## Solution
Docs now should describe what the _front_, _first_, _back_, and _last_ elements are for an implementor of the `bevy::reflect::list::List` Trait. Further, the docs should describe how `bevy::reflect::list::List::push` and `bevy::reflect::list::List::pop` should act on these elements.
Co-authored-by: Linus Käll <linus.kall.business@gmail.com>
# Objective
- Fixes#3004
## Solution
- Replaced all the types with their fully quallified names
- Replaced all trait methods and inherent methods on dyn traits with their fully qualified names
- Made a new file `fq_std.rs` that contains structs corresponding to commonly used Structs and Traits from `std`. These structs are replaced by their respective fully qualified names when used inside `quote!`
# Objective
> Followup to [this](https://github.com/bevyengine/bevy/pull/6755#discussion_r1032671178) comment
Rearrange the impls in the `impls/std.rs` file.
The issue was that I had accidentally misplaced the impl for `Option<T>` and put it between the `Cow<'static, str>` impls. This is just a slight annoyance and readability issue.
## Solution
Move the `Option<T>` and `&'static Path` impls around to be more readable.
# Objective
Fixes#6739
## Solution
Implement the required traits. They cannot be implemented for `Path` directly, since it is a dynamically-sized type.
# Objective
> Part of #6573
When serializing a `DynamicScene` we end up treating almost all non-value types as though their type data doesn't exist. This is because when creating the `DynamicScene` we call `Reflect::clone_value` on the components, which generates a Dynamic type for all non-value types.
What this means is that the `glam` types are treated as though their `ReflectSerialize` registrations don't exist. However, the deserializer _does_ pick up the registration and attempts to use that instead. This results in the deserializer trying to operate on "malformed" data, causing this error:
```
WARN bevy_asset::asset_server: encountered an error while loading an asset: Expected float
```
## Solution
Ideally, we should better handle the serialization of possibly-Dynamic types. However, this runs into issues where the `ReflectSerialize` expects the concrete type and not a Dynamic representation, resulting in a panic:
0aa4147af6/crates/bevy_reflect/src/type_registry.rs (L402-L413)
Since glam types are so heavily used in Bevy (specifically in `Transform` and `GlobalTransform`), it makes sense to just a quick fix in that enables them to be used properly in scenes while a proper solution is found.
This PR simply removes all `ReflectSerialize` and `ReflectDeserialize` registrations from the glam types that are reflected as structs.
---
## Changelog
- Remove `ReflectSerialize` and `ReflectDeserialize` registrations from most glam types
## Migration Guide
This PR removes `ReflectSerialize` and `ReflectDeserialize` registrations from most glam types. This means any code relying on either of those type data existing for those glam types will need to not do that.
This also means that some serialized glam types will need to be updated. For example, here is `Affine3A`:
```rust
// BEFORE
(
"glam::f32::affine3a::Affine3A": (1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0),
// AFTER
"glam::f32::affine3a::Affine3A": (
matrix3: (
x_axis: (
x: 1.0,
y: 0.0,
z: 0.0,
),
y_axis: (
x: 0.0,
y: 1.0,
z: 0.0,
),
z_axis: (
x: 0.0,
y: 0.0,
z: 1.0,
),
),
translation: (
x: 0.0,
y: 0.0,
z: 0.0,
),
)
)
```
# Objective
Fixes#6713
Binary deserialization is failing for unit structs as well as structs with all ignored/skipped fields.
## Solution
Add a check for the number of possible fields in a struct before deserializing. If empty, don't attempt to deserialize any fields (as there will be none).
Note: ~~This does not apply to enums as they do not properly handle skipped fields (see #6721).~~ Enums still do not properly handle skipped fields, but I decided to include the logic for it anyways to account for `#[reflect(ignore)]`'d fields in the meantime.
---
## Changelog
- Fix bug where deserializing unit structs would fail for non-self-describing formats
