Commit graph

224 commits

Author SHA1 Message Date
Nicola Papale
10797d4f15
Refactor parsing in bevy_reflect path module (#9048)
# Objective

- Follow up to #8887
- The parsing code in `bevy_reflect/src/path/mod.rs` could also do with
some cleanup

## Solution

- Create the `parse.rs` module, move all parsing code to this module
- The parsing errors also now keep track of the whole parsed string, and
are much more fine-grained

### Detailed changes

- Move `PathParser` to `parse.rs` submodule
- Rename `token_to_access` to `access_following` (yep, goes from 132
lines to 16)
- Move parsing tests into the `parse.rs` file
2023-08-05 17:18:13 +00:00
PortalRising
f14300e5d3
Implement reflect trait on new glam types (I64Vec and U64Vec) (#9281)
# Objective
Glam 0.24 added new glam types (```I64Vec``` and ```U64Vec```). However
these are not reflectable unlike the other glam types

## Solution
Implement reflect for these new types

---

## Changelog
Implements reflect with the impl_reflect_struct macro on ```I64Vec2```,
```I64Vec3```, ```I64Vec4```, ```U64Vec2```, ```U64Vec3```, and
```U64Vec4``` types
2023-07-31 19:18:21 +00:00
Nicola Papale
08ea1d18ae
Refactor path module of bevy_reflect (#8887)
# Objective

- The `path` module was getting fairly large.
- The code in `AccessRef::read_element` and mut equivalent was very
complex and difficult to understand.
- The `ReflectPathError` had a lot of variants, and was difficult to
read.

## Solution

- Split the file in two, `access` now has its own module
- Rewrite the `read_element` methods, they were ~200 lines long, they
are now ~70 lines long — I didn't change any of the logic. It's really
just the same code, but error handling is separated.
- Split the `ReflectPathError` error
- Merge `AccessRef` and `Access`
- A few other changes that aim to reduce code complexity

### Fully detailed change list

- `Display` impl of `ParsedPath` now includes prefix dots — this allows
simplifying its implementation, and IMO `.path.to.field` is a better way
to express a "path" than `path.to.field` which could suggest we are
reading the `to` field of a variable named `path`
- Add a test to check that dot prefixes and other are correctly parsed —
Until now, no test contained a prefixing dot
- Merge `Access` and `AccessRef`, using a `Cow<'a, str>`. Generated code
seems to agree with this decision (`ParsedPath::parse` sheds 5% of
instructions)
- Remove `Access::as_ref` since there is no such thing as an `AccessRef`
anymore.
- Rename `AccessRef::to_owned` into `AccessRef::into_owned()` since it
takes ownership of `self` now.
- Add a `parse_static` that doesn't allocate new strings for named
fields!
- Add a section about path reflection in the `bevy_reflect` crate root
doc — I saw a few people that weren't aware of path reflection, so I
thought it was pertinent to add it to the root doc
- a lot of nits
- rename `index` to `offset` when it refers to offset in the path string
— There is no more confusion with the other kind of indices in this
context, also it's a common naming convention for parsing.
  - Make a dedicated enum for parsing errors
- rename the `read_element` methods to `element` — shorter, but also
`read_element_mut` was a fairly poor name
- The error values now not only contain the expected type but also the
actual type.
- Remove lifetimes that could be inferred from the `GetPath` trait
methods.

---

## Change log

- Added the `ParsedPath::parse_static` method, avoids allocating when
parsing `&'static str`.

## Migration Guide

If you were matching on the `Err(ReflectPathError)` value returned by
`GetPath` and `ParsedPath` methods, now only the parse-related errors
and the offset are publicly accessible. You can always use the
`fmt::Display` to get a clear error message, but if you need
programmatic access to the error types, please open an issue.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2023-07-30 19:17:07 +00:00
Arnav Mummineni
bc8e2746d7
Add reflect impls to IRect and URect (#9191)
# Objective

This attempts to make the new IRect and URect structs in bevy_math more
similar to the existing Rect struct.

## Solution

Add reflect implementations for IRect and URect, since one already
exists for Rect.
2023-07-23 01:02:00 +00:00
Carter Anderson
7c3131a761
Bump Version after Release (#9106)
CI-capable version of #9086

---------

Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François <mockersf@gmail.com>
2023-07-10 21:19:27 +00:00
Cptn-Sherman
aa03130234
Fix typo in NamedTypePathDef (#9102)
# Objective
Fixes #9091 

## Solution
Rename instances of `Primtive` to `Primitive`

## Migration Guide

Before: 

```rust 
let type_path = NamedTypePathDef::Primtive(ident);
```

After: 
```rust
let type_path = NamedTypePathDef::Primitive(ident);
```
2023-07-10 17:02:16 +00:00
ClayenKitten
ffc572728f
Fix typos throughout the project (#9090)
# Objective

Fix typos throughout the project.

## Solution

[`typos`](https://github.com/crate-ci/typos) project was used for
scanning, but no automatic corrections were applied. I checked
everything by hand before fixing.

Most of the changes are documentation/comments corrections. Also, there
are few trivial changes to code (variable name, pub(crate) function name
and a few error/panic messages).

## Unsolved

`bevy_reflect_derive` has
[typo](1b51053f19/crates/bevy_reflect/bevy_reflect_derive/src/type_path.rs (L76))
in enum variant name that I didn't fix. Enum is `pub(crate)`, so there
shouldn't be any trouble if fixed. However, code is tightly coupled with
macro usage, so I decided to leave it for more experienced contributor
just in case.
2023-07-10 00:11:51 +00:00
Carter Anderson
8ba9571eed
Release 0.11.0 (#9080)
I created this manually as Github didn't want to run CI for the
workflow-generated PR. I'm guessing we didn't hit this in previous
releases because we used bors.

Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
2023-07-09 08:43:47 +00:00
Gino Valente
aeeb20ec4c
bevy_reflect: FromReflect Ergonomics Implementation (#6056)
# Objective

**This implementation is based on
https://github.com/bevyengine/rfcs/pull/59.**

---

Resolves #4597

Full details and motivation can be found in the RFC, but here's a brief
summary.

`FromReflect` is a very powerful and important trait within the
reflection API. It allows Dynamic types (e.g., `DynamicList`, etc.) to
be formed into Real ones (e.g., `Vec<i32>`, etc.).

This mainly comes into play concerning deserialization, where the
reflection deserializers both return a `Box<dyn Reflect>` that almost
always contain one of these Dynamic representations of a Real type. To
convert this to our Real type, we need to use `FromReflect`.

It also sneaks up in other ways. For example, it's a required bound for
`T` in `Vec<T>` so that `Vec<T>` as a whole can be made `FromReflect`.
It's also required by all fields of an enum as it's used as part of the
`Reflect::apply` implementation.

So in other words, much like `GetTypeRegistration` and `Typed`, it is
very much a core reflection trait.

The problem is that it is not currently treated like a core trait and is
not automatically derived alongside `Reflect`. This makes using it a bit
cumbersome and easy to forget.

## Solution

Automatically derive `FromReflect` when deriving `Reflect`.

Users can then choose to opt-out if needed using the
`#[reflect(from_reflect = false)]` attribute.

```rust
#[derive(Reflect)]
struct Foo;

#[derive(Reflect)]
#[reflect(from_reflect = false)]
struct Bar;

fn test<T: FromReflect>(value: T) {}

test(Foo); // <-- OK
test(Bar); // <-- Panic! Bar does not implement trait `FromReflect`
```

#### `ReflectFromReflect`

This PR also automatically adds the `ReflectFromReflect` (introduced in
#6245) registration to the derived `GetTypeRegistration` impl— if the
type hasn't opted out of `FromReflect` of course.

<details>
<summary><h4>Improved Deserialization</h4></summary>

> **Warning**
> This section includes changes that have since been descoped from this
PR. They will likely be implemented again in a followup PR. I am mainly
leaving these details in for archival purposes, as well as for reference
when implementing this logic again.

And since we can do all the above, we might as well improve
deserialization. We can now choose to deserialize into a Dynamic type or
automatically convert it using `FromReflect` under the hood.

`[Un]TypedReflectDeserializer::new` will now perform the conversion and
return the `Box`'d Real type.

`[Un]TypedReflectDeserializer::new_dynamic` will work like what we have
now and simply return the `Box`'d Dynamic type.

```rust
// Returns the Real type
let reflect_deserializer = UntypedReflectDeserializer::new(&registry);
let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?;

let output: SomeStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?;

// Returns the Dynamic type
let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(&registry);
let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?;

let output: DynamicStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?;
```

</details>

---

## Changelog

* `FromReflect` is now automatically derived within the `Reflect` derive
macro
* This includes auto-registering `ReflectFromReflect` in the derived
`GetTypeRegistration` impl
* ~~Renamed `TypedReflectDeserializer::new` and
`UntypedReflectDeserializer::new` to
`TypedReflectDeserializer::new_dynamic` and
`UntypedReflectDeserializer::new_dynamic`, respectively~~ **Descoped**
* ~~Changed `TypedReflectDeserializer::new` and
`UntypedReflectDeserializer::new` to automatically convert the
deserialized output using `FromReflect`~~ **Descoped**

## Migration Guide

* `FromReflect` is now automatically derived within the `Reflect` derive
macro. Items with both derives will need to remove the `FromReflect`
one.

  ```rust
  // OLD
  #[derive(Reflect, FromReflect)]
  struct Foo;
  
  // NEW
  #[derive(Reflect)]
  struct Foo;
  ```

If using a manual implementation of `FromReflect` and the `Reflect`
derive, users will need to opt-out of the automatic implementation.

  ```rust
  // OLD
  #[derive(Reflect)]
  struct Foo;
  
  impl FromReflect for Foo {/* ... */}
  
  // NEW
  #[derive(Reflect)]
  #[reflect(from_reflect = false)]
  struct Foo;
  
  impl FromReflect for Foo {/* ... */}
  ```

<details>
<summary><h4>Removed Migrations</h4></summary>

> **Warning**
> This section includes changes that have since been descoped from this
PR. They will likely be implemented again in a followup PR. I am mainly
leaving these details in for archival purposes, as well as for reference
when implementing this logic again.

* The reflect deserializers now perform a `FromReflect` conversion
internally. The expected output of `TypedReflectDeserializer::new` and
`UntypedReflectDeserializer::new` is no longer a Dynamic (e.g.,
`DynamicList`), but its Real counterpart (e.g., `Vec<i32>`).

  ```rust
let reflect_deserializer =
UntypedReflectDeserializer::new_dynamic(&registry);
  let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?;
  
  // OLD
let output: DynamicStruct = reflect_deserializer.deserialize(&mut
deserializer)?.take()?;
  
  // NEW
let output: SomeStruct = reflect_deserializer.deserialize(&mut
deserializer)?.take()?;
  ```

Alternatively, if this behavior isn't desired, use the
`TypedReflectDeserializer::new_dynamic` and
`UntypedReflectDeserializer::new_dynamic` methods instead:

  ```rust
  // OLD
  let reflect_deserializer = UntypedReflectDeserializer::new(&registry);
  
  // NEW
let reflect_deserializer =
UntypedReflectDeserializer::new_dynamic(&registry);
  ```

</details>

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2023-06-29 01:31:34 +00:00
radiish
e17fc53aa1
reflect: avoid deadlock in GenericTypeCell (#8957)
# Objective

- There was a deadlock discovered in the implementation of
`bevy_reflect::utility::GenericTypeCell`, when called on a recursive
type, e.g. `Vec<Vec<VariableCurve>>`

## Solution

- Drop the lock before calling the initialisation function, and then
pick it up again afterwards.

## Additional Context
- [Discussed on
Discord](https://discord.com/channels/691052431525675048/1002362493634629796/1122706835284185108)
2023-06-27 18:07:49 +00:00
Giacomo Stevanato
0f4d16aa3c
Don't ignore additional entries in UntypedReflectDeserializerVisitor (#7112)
# Objective

Currently when `UntypedReflectDeserializerVisitor` deserializes a
`Box<dyn Reflect>` it only considers the first entry of the map,
silently ignoring any additional entries. For example the following RON
data:

```json
{
    "f32": 1.23,
    "u32": 1,
}
```

is successfully deserialized as a `f32`, completly ignoring the `"u32":
1` part.

## Solution

`UntypedReflectDeserializerVisitor` was changed to check if any other
key could be deserialized, and in that case returns an error.

---

## Changelog

`UntypedReflectDeserializer` now errors on malformed inputs instead of
silently disgarding additional data.

## Migration Guide

If you were deserializing `Box<dyn Reflect>` values with multiple
entries (i.e. entries other than `"type": { /* fields */ }`) you should
remove them or deserialization will fail.
2023-06-26 19:32:27 +00:00
Joaquín León
af4336c501
Reflect UUID (#8905)
For those who wish to be able to `#[reflect]` stuff using the `Uuid`
type

I'm very unfamiliar with the codebase, so please tell me if I'm missing
something
2023-06-21 17:24:32 +00:00
Nicola Papale
23863d526a
Do not require mut on ParsedPath::element_mut (#8891)
# Objective

`ParsedPath` does not need to be mut to access a field of a `Reflect`.
Be that access mutable or not. Yet `element_mut` requires a mutable
borrow on `self`.

## Solution

- Make `element_mut` take a `&self` over a `&mut self`.

#8887 fixes this, but this is a major limitation in the API and I'd
rather see it merged before 0.11.

---

## Changelog

- `ParsedPath::element_mut` and `ParsedPath::reflect_element_mut` now
accept a non-mutable `ParsedPath` (only the accessed `Reflect` needs to
be mutable)
2023-06-19 15:27:45 +00:00
EliasPrescott
e6b655fb25
adding reflection for Cow<'static, [T]> (#7454)
# Objective

- Implementing reflection for Cow<'static, [T]>
- Hopefully fixes #7429

## Solution

- Implementing Reflect, Typed, GetTypeRegistration, and FromReflect for
Cow<'static, [T]>

---

## Notes

I have not used bevy_reflection much yet, so I may not fully understand
all the use cases. This is also my first attempt at contributing, so I
would appreciate any feedback or recommendations for changes. I tried to
add cases for using Cow<'static, str> and Cow<'static, [u8]> to some of
the bevy_reflect tests, but I can't guarantee those tests are
comprehensive enough.

---------

Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-06-19 14:58:49 +00:00
Thierry Berger
b559e9b6b4
bevy_reflect: implement Reflect for SmolStr (#8771)
# Objective
To upgrade winit's dependency, it's useful to reuse SmolStr, which
replaces/improves the too restrictive Key letter enums.

As Input<Key> is a resource it should implement Reflect through all its
fields.

## Solution

Add smol_str to bevy_reflect supported types, behind a feature flag.

This PR blocks winit's upgrade PR:
https://github.com/bevyengine/bevy/pull/8745.

# Current state

- I'm discovering bevy_reflect, I appreciate all feedbacks, and send me
your nitpicks!
- Lacking more tests

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2023-06-08 20:33:21 +00:00
Carter Anderson
8b9d88f4d0
Reflect now requires DynamicTypePath. Remove Reflect::get_type_path() (#8764)
Followup to #7184

This makes `Reflect: DynamicTypePath` which allows us to remove
`Reflect::get_type_path`, reducing unnecessary codegen and simplifying
`Reflect` implementations.
2023-06-06 17:23:58 +00:00
Jamie Ridding
1e97c79ec1
bevy_reflect: Disambiguate type bounds in where clauses. (#8761)
# Objective

It was accidentally found that rustc is unable to parse certain
constructs in `where` clauses properly. `bevy_reflect::Reflect`'s habit
of copying and pasting the field types in a type's definition to its
`where` clauses made it very easy to accidentally run into this
behaviour - particularly with the construct
```rust
where
    for<'a> fn(&'a T) -> &'a T: Trait1 + Trait2
```

which was incorrectly parsed as
```rust
where
    for<'a> (fn(&'a T) -> &'a T: Trait1 + Trait2)
            ^                                   ^ incorrect syntax grouping
```

instead of
```rust
where
    (for<'a> fn(&'a T) -> &'a T): Trait1 + Trait2
    ^                          ^ correct syntax grouping
```

Fixes #8759 

## Solution

This commit fixes the issue by inserting explicit parentheses to
disambiguate types from their bound lists.
2023-06-05 22:47:08 +00:00
radiish
1efc762924
reflect: stable type path v2 (#7184)
# Objective

- Introduce a stable alternative to
[`std::any::type_name`](https://doc.rust-lang.org/std/any/fn.type_name.html).
- Rewrite of #5805 with heavy inspiration in design.
- On the path to #5830.
- Part of solving #3327.


## Solution

- Add a `TypePath` trait for static stable type path/name information.
- Add a `TypePath` derive macro.
- Add a `impl_type_path` macro for implementing internal and foreign
types in `bevy_reflect`.

---

## Changelog

- Added `TypePath` trait.
- Added `DynamicTypePath` trait and `get_type_path` method to `Reflect`.
- Added a `TypePath` derive macro.
- Added a `bevy_reflect::impl_type_path` for implementing `TypePath` on
internal and foreign types in `bevy_reflect`.
- Changed `bevy_reflect::utility::(Non)GenericTypeInfoCell` to
`(Non)GenericTypedCell<T>` which allows us to be generic over both
`TypeInfo` and `TypePath`.
- `TypePath` is now a supertrait of `Asset`, `Material` and
`Material2d`.
- `impl_reflect_struct` needs a `#[type_path = "..."]` attribute to be
specified.
- `impl_reflect_value` needs to either specify path starting with a
double colon (`::core::option::Option`) or an `in my_crate::foo`
declaration.
- Added `bevy_reflect_derive::ReflectTypePath`.
- Most uses of `Ident` in `bevy_reflect_derive` changed to use
`ReflectTypePath`.

## Migration Guide

- Implementors of `Asset`, `Material` and `Material2d` now also need to
derive `TypePath`.
- Manual implementors of `Reflect` will need to implement the new
`get_type_path` method.

## Open Questions
- [x] ~This PR currently does not migrate any usages of
`std::any::type_name` to use `bevy_reflect::TypePath` to ease the review
process. Should it?~ Migration will be left to a follow-up PR.
- [ ] This PR adds a lot of `#[derive(TypePath)]` and `T: TypePath` to
satisfy new bounds, mostly when deriving `TypeUuid`. Should we make
`TypePath` a supertrait of `TypeUuid`? [Should we remove `TypeUuid` in
favour of
`TypePath`?](2afbd85532 (r961067892))
2023-06-05 20:31:20 +00:00
Егор Куклин
6b4c7d5d88
Add get_at_mut to bevy_reflect::Map trait (#8691)
# 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.
2023-06-02 12:24:40 +00:00
Gauthier Acquitter
acf1362b9a
bevy_reflect: Allow construction of MapIter outside of the bevy_reflect crate. (#8723)
# 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.
2023-06-01 10:12:57 +00:00
Gino Valente
6b292d4263
bevy_reflect: Allow #[reflect(default)] on enum variant fields (#8514)
# 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)]`
2023-05-29 15:29:29 +00:00
François
0736195a1e
update syn, encase, glam and hexasphere (#8573)
# Objective

- Fixes #8282 
- Update `syn` to 2.0, `encase` to 0.6, `glam` to 0.24 and `hexasphere`
to 9.0


Blocked ~~on https://github.com/teoxoy/encase/pull/42~~ and ~~on
https://github.com/OptimisticPeach/hexasphere/pull/17~~

---------

Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
2023-05-16 01:24:17 +00:00
Mincho Paskalev
fe57b9f744
Add Reflect and FromReflect for AssetPath (#8531)
# 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>`.
2023-05-08 19:19:19 +00:00
Gino Valente
75130bd5ec
bevy_reflect: Better proxies (#6971)
# 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>
2023-04-26 12:17:46 +00:00
Gino Valente
74d425263a
bevy_reflect: Add ReflectFromReflect to the prelude (#8496)
# 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.
2023-04-26 12:16:17 +00:00
Wybe Westra
abf12f3b3b
Fixed several missing links in docs. (#8117)
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>
2023-04-23 17:28:36 +00:00
Noah
a9f766ceb2
Fix Box<dyn Reflect> struct with a hashmap in it panicking when clone_value is called on it (#8184)
# 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
2023-04-22 02:55:53 +00:00
Mikkel Rasmussen
e9312254d8
Non-breaking change* from UK spellings to US (#8291)
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
2023-04-08 16:22:46 +00:00
JoJoJet
3ead10a3e0
Suppress the clippy::type_complexity lint (#8313)
# 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.
2023-04-06 21:27:36 +00:00
fren_gor
253db50c63
Fix typo in bevy_reflect README (#8281)
# 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`
2023-04-01 03:01:44 +00:00
Gino Valente
5e5a305d43
bevy_reflect: Fix trailing comma breaking derives (#8014)
# 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
2023-03-27 21:47:33 +00:00
Ikko Eltociear Ashimine
e22572d9a3
Fix typo in utility.rs (#7997) 2023-03-09 09:20:45 +00:00
Rob Parrett
2908bb5e8a
Use derive for default impl of DynamicVariant (#7986) 2023-03-08 22:27:54 +00:00
github-actions[bot]
6898351348
chore: Release (#7920)
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
2023-03-06 05:13:36 +00:00
github-actions[bot]
b44af49200 Release 0.10.0 (#7919)
Preparing next release
This PR has been auto-generated
2023-03-06 03:53:02 +00:00
github-actions[bot]
8eb67932f1 Bump Version after Release (#7918)
Bump version after release
This PR has been auto-generated
2023-03-06 02:10:30 +00:00
Edgar Geier
cbbf8ac575 Update glam to 0.23 (#7883)
# 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.
2023-03-04 11:42:27 +00:00
TheBigCheese
3d3444b981 impl Reflect for std::collections::HashMap instead of only bevy::utils::HashMap (#7739) (#7782)
# 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`
2023-02-27 21:37:36 +00:00
Gino Valente
a89277d5bf bevy_reflect: Add missing primitive registrations (#7815)
# Objective

There were a couple primitive types missing from the default `TypeRegistry` constructor.

## Solution

Added the missing registrations for `char` and `String`.
2023-02-25 21:51:06 +00:00
Rob Parrett
03c545056c Fix some more typos (#7767)
# Objective

I managed to dig up some more typos with a combination of the "[code spell checker](https://marketplace.visualstudio.com/items?itemName=streetsidesoftware.code-spell-checker)" and "[open folder](https://marketplace.visualstudio.com/items?itemName=rwu823.open-folder)" vscode extensions.

## Solution

Fix em
2023-02-20 23:36:28 +00:00
Rob Parrett
e6d60ad24e Fix clippy lint (#7765)
# 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.
2023-02-20 22:56:58 +00:00
Gino Valente
cd1737ecca bevy_reflect: Improved documentation (#7148)
# 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>
2023-02-18 20:42:01 +00:00
Johan Klokkhammer Helsing
18cfb226db Use a fixed state hasher in bevy_reflect for deterministic Reflect::reflect_hash() across processes (#7583)
# 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.
2023-02-17 15:37:35 +00:00
dis-da-moe
8853bef6df implement TypeUuid for primitives and fix multiple-parameter generics having the same TypeUuid (#6633)
# 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>
2023-02-16 17:09:44 +00:00
Gino Valente
724b36289c bevy_reflect: Decouple List and Array traits (#7467)
# 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`
2023-02-13 21:07:53 +00:00
Gino Valente
357a16035d bevy_reflect: Support tuple reflection paths (#7324)
# 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
2023-02-06 21:22:45 +00:00
CrystaLamb
4fd092fbec fix typo in bevy_reflect::impls::std GetTypeRegistration for vec like… (#7520)
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.
2023-02-06 12:58:21 +00:00
MinerSebas
e5b522064c Follow up on Todo in bevy_reflect_derive (#7461)
# Objective

Follow up on Todo in bevy_reflect_derive

## Solution

- Replaced all Instances that do the same as `ident_or_index` with a call to it.
- Only the following Line wasn't replaced, as it only wants the index, and not the ident:
[69fc8c6b70/crates/bevy_reflect/bevy_reflect_derive/src/impls/tuple_structs.rs (L18))
2023-02-02 04:37:32 +00:00
Elbert Ronnie
615d3d2157 Add constructor new to ArrayIter (#7449)
# 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>
2023-01-31 23:19:19 +00:00
Charles Bournhonesque
cbb4c26cad Enable deriving Reflect on structs with generic types (#7364)
# 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)
2023-01-28 00:12:06 +00:00