# Objective
As pointed out by @SkiFire13 on
[Discord](https://discord.com/channels/691052431525675048/1002362493634629796/1270624366119485441),
I was incorrect in #14641 regarding the type name of anonymous
functions. I had stated that they will return something like `fn(i32,
i32) -> i32`, but this is wrong. They actually behave like closures
(despite not technically being closures) and return something more like
`foo::bar::{{closure}}`.
This isn't a major issue because the reasoning behind #14641 still
stands. However, the internal documentation should probably be updated
so future contributors don't believe the lies I left behind.
## Solution
Updated the internal documentation for `create_info` to reflect the
actual type name of an anonymous function.
In that same module, I also added a test for function pointers and
updated all tests to include sanity checks for the `std::any::type_name`
of each category of callable.
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
# Objective
### TL;DR
#14098 added the `FunctionRegistry` but had some last minute
complications due to anonymous functions. It ended up going with a
"required name" approach to ensure anonymous functions would always have
a name.
However, this approach isn't ideal for named functions since, by
definition, they will always have a name.
Therefore, this PR aims to modify function reflection such that we can
make function registration easier for named functions, while still
allowing anonymous functions to be registered as well.
### Context
Function registration (#14098) ran into a little problem: anonymous
functions.
Anonymous functions, including function pointers, have very non-unique
type names. For example, the anonymous function `|a: i32, b: i32| a + b`
has the type name of `fn(i32, i32) -> i32`. This obviously means we'd
conflict with another function like `|a: i32, b: i32| a - b`.
The solution that #14098 landed on was to always require a name during
function registration.
The downside with this is that named functions (e.g. `fn add(a: i32, b:
i32) -> i32 { a + b }`) had to redundantly provide a name. Additionally,
manually constructed `DynamicFunction`s also ran into this ergonomics
issue.
I don't entirely know how the function registry will be used, but I have
a strong suspicion that most of its registrations will either be named
functions or manually constructed `DynamicFunction`s, with anonymous
functions only being used here and there for quick prototyping or adding
small functionality.
Why then should the API prioritize the anonymous function use case by
always requiring a name during registration?
#### Telling Functions Apart
Rust doesn't provide a lot of out-of-the-box tools for reflecting
functions. One of the biggest hurdles in attempting to solve the problem
outlined above would be to somehow tell the different kinds of functions
apart.
Let's briefly recap on the categories of functions in Rust:
| Category | Example |
| ------------------ | ----------------------------------------- |
| Named function | `fn add(a: i32, b: i32) -> i32 { a + b }` |
| Closure | `\|a: i32\| a + captured_variable` |
| Anonymous function | `\|a: i32, b: i32\| a + b` |
| Function pointer | `fn(i32, i32) -> i32` |
My first thought was to try and differentiate these categories based on
their size. However, we can see that this doesn't quite work:
| Category | `size_of` |
| ------------------ | --------- |
| Named function | 0 |
| Closure | 0+ |
| Anonymous function | 0 |
| Function pointer | 8 |
Not only does this not tell anonymous functions from named ones, but it
struggles with pretty much all of them.
My second then was to differentiate based on type name:
| Category | `type_name` |
| ------------------ | ----------------------- |
| Named function | `foo::bar::baz` |
| Closure | `foo::bar::{{closure}}` |
| Anonymous function | `fn() -> String` |
| Function pointer | `fn() -> String` |
This is much better. While it can't distinguish between function
pointers and anonymous functions, this doesn't matter too much since we
only care about whether we can _name_ the function.
So why didn't we implement this in #14098?
#### Relying on `type_name`
While this solution was known about while working on #14098, it was left
out from that PR due to it being potentially controversial.
The [docs](https://doc.rust-lang.org/stable/std/any/fn.type_name.html)
for `std::any::type_name` state:
> The returned string must not be considered to be a unique identifier
of a type as multiple types may map to the same type name. Similarly,
there is no guarantee that all parts of a type will appear in the
returned string: for example, lifetime specifiers are currently not
included. In addition, the output may change between versions of the
compiler.
So that's it then? We can't use `type_name`?
Well, this statement isn't so much a rule as it is a guideline. And Bevy
is no stranger to bending the rules to make things work or to improve
ergonomics. Remember that before `TypePath`, Bevy's scene system was
entirely dependent on `type_name`. Not to mention that `type_name` is
being used as a key into both the `TypeRegistry` and the
`FunctionRegistry`.
Bevy's practices aside, can we reliably use `type_name` for this?
My answer would be "yes".
Anonymous functions are anonymous. They have no name. There's nothing
Rust could do to give them a name apart from generating a random string
of characters. But remember that this is a diagnostic tool, it doesn't
make sense to obfuscate the type by randomizing the output. So changing
it to be anything other than what it is now is very unlikely.
The only changes that I could potentially see happening are:
1. Closures replace `{{closure}}` with the name of their variable
2. Lifetimes are included in the output
I don't think the first is likely to happen, but if it does then it
actually works out in our favor: closures are now named!
The second point is probably the likeliest. However, adding lifetimes
doesn't mean we can't still rely on `type_name` to determine whether or
not a function is named. So we should be okay in this case as well.
## Solution
Parse the `type_name` of the function in the `TypedFunction` impl to
determine if the function is named or anonymous.
This once again makes `FunctionInfo::name` optional. For manual
constructions of `DynamicFunction`, `FunctionInfo::named` or
``FunctionInfo::anonymous` can be used.
The `FunctionRegistry` API has also been reworked to account for this
change.
`FunctionRegistry::register` no longer takes a name and instead takes it
from the supplied function, returning a
`FunctionRegistrationError::MissingName` error if the name is `None`.
This also doubles as a replacement for the old
`FunctionRegistry::register_dynamic` method, which has been removed.
To handle anonymous functions, a `FunctionRegistry::register_with_name`
method has been added. This works in the same way
`FunctionRegistry::register` used to work before this PR.
The overwriting methods have been updated in a similar manner, with
modifications to `FunctionRegistry::overwrite_registration`, the removal
of `FunctionRegistry::overwrite_registration_dynamic`, and the addition
of `FunctionRegistry::overwrite_registration_with_name`.
This PR also updates the methods on `App` in a similar way:
`App::register_function` no longer requires a name argument and
`App::register_function_with_name` has been added to handle anonymous
functions (and eventually closures).
## Testing
You can run the tests locally by running:
```
cargo test --package bevy_reflect --features functions
```
---
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
> [!note]
> This list is not exhaustive. It only contains some of the most
important changes.
`FunctionRegistry::register` no longer requires a name string for named
functions. Anonymous functions, however, need to be registered using
`FunctionRegistry::register_with_name`.
```rust
// BEFORE
registry
.register(std::any::type_name_of_val(&foo), foo)?
.register("bar", || println!("Hello world!"));
// AFTER
registry
.register(foo)?
.register_with_name("bar", || println!("Hello world!"));
```
`FunctionInfo::name` is now optional. Anonymous functions and closures
will now have their name set to `None` by default. Additionally,
`FunctionInfo::new` has been renamed to `FunctionInfo::named`.
# Objective
Support for reflecting set-like types (e.g. `HashSet`) was added in
#13014. However, we didn't add any serialization tests to verify that
serialization works as expected.
## Solution
Update the serde tests.
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
Basically it's https://github.com/bevyengine/bevy/pull/13792 with the
bumped versions of `encase` and `hexasphere`.
---------
Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
#13152 added support for reflecting functions. Now, we need a way to
register those functions such that they may be accessed anywhere within
the ECS.
## Solution
Added a `FunctionRegistry` type similar to `TypeRegistry`.
This allows a function to be registered and retrieved by name.
```rust
fn foo() -> i32 {
123
}
let mut registry = FunctionRegistry::default();
registry.register("my_function", foo);
let function = registry.get_mut("my_function").unwrap();
let value = function.call(ArgList::new()).unwrap().unwrap_owned();
assert_eq!(value.downcast_ref::<i32>(), Some(&123));
```
Additionally, I added an `AppFunctionRegistry` resource which wraps a
`FunctionRegistryArc`. Functions can be registered into this resource
using `App::register_function` or by getting a mutable reference to the
resource itself.
### Limitations
#### `Send + Sync`
In order to get this registry to work across threads, it needs to be
`Send + Sync`. This means that `DynamicFunction` needs to be `Send +
Sync`, which means that its internal function also needs to be `Send +
Sync`.
In most cases, this won't be an issue because standard Rust functions
(the type most likely to be registered) are always `Send + Sync`.
Additionally, closures tend to be `Send + Sync` as well, granted they
don't capture any `!Send` or `!Sync` variables.
This PR adds this `Send + Sync` requirement, but as mentioned above, it
hopefully shouldn't be too big of an issue.
#### Closures
Unfortunately, closures can't be registered yet. This will likely be
explored and added in a followup PR.
### Future Work
Besides addressing the limitations listed above, another thing we could
look into is improving the lookup of registered functions. One aspect is
in the performance of hashing strings. The other is in the developer
experience of having to call `std::any::type_name_of_val` to get the
name of their function (assuming they didn't give it a custom name).
## Testing
You can run the tests locally with:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Added `FunctionRegistry`
- Added `AppFunctionRegistry` (a `Resource` available from `bevy_ecs`)
- Added `FunctionRegistryArc`
- Added `FunctionRegistrationError`
- Added `reflect_functions` feature to `bevy_ecs` and `bevy_app`
- `FunctionInfo` is no longer `Default`
- `DynamicFunction` now requires its wrapped function be `Send + Sync`
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
`DynamicFunction` (both those created manually and those created with
`IntoFunction`), now require `Send + Sync`. All standard Rust functions
should meet that requirement. Closures, on the other hand, may not if
they capture any `!Send` or `!Sync` variables from its environment.
Fixes#14418
Note that this does not add AtomicPtr, which would need its own special
casing support, just the regular value types.
Also, I was forced to be opinionated about which Ordering to use, so I
chose SeqCst as the strictest by default.
# Objective
- Fix issue #2611
## Solution
- Add `--generate-link-to-definition` to all the `rustdoc-args` arrays
in the `Cargo.toml`s (for docs.rs)
- Add `--generate-link-to-definition` to the `RUSTDOCFLAGS` environment
variable in the docs workflow (for dev-docs.bevyengine.org)
- Document all the workspace crates in the docs workflow (needed because
otherwise only the source code of the `bevy` package will be included,
making the argument useless)
- I think this also fixes#3662, since it fixes the bug on
dev-docs.bevyengine.org, while on docs.rs it has been fixed for a while
on their side.
---
## Changelog
- The source code viewer on docs.rs now includes links to the
definitions.
# Objective
I just wanted to inspect `HashSet`s in `bevy-inspector-egui` but I
noticed that it didn't work for some reason. A few minutes later I found
myself looking into the bevy reflect impls noticing that `HashSet`s have
been covered only rudimentary up until now.
## Solution
I'm not sure if this is overkill (especially the first bullet), but
here's a list of the changes:
- created a whole new trait and enum variants for `ReflectRef` and the
like called `Set`
- mostly oriented myself at the `Map` trait and made the necessary
changes until RA was happy
- create macro `impl_reflect_for_hashset!` and call it on `std::HashSet`
and `hashbrown::HashSet`
Extra notes:
- no `get_mut` or `get_mut_at` mirroring the `std::HashSet`
- `insert[_boxed]` and `remove` return `bool` mirroring `std::HashSet`,
additionally that bool is reflect as I thought that would be how we
handle things in bevy reflect, but I'm not sure on this
- ser/de are handled via `SeqAccess`
- I'm not sure about the general deduplication property of this impl of
`Set` that is generally expected? I'm also not sure yet if `Map` does
provide this. This mainly refers to the `Dynamic[...]` structs
- I'm not sure if there are other methods missing from the `trait`, I
felt like `contains` or the set-operations (union/diff/...) could've
been helpful, but I wanted to get out the bare minimum for feedback
first
---
## Changelog
### Added
- `Set` trait for `bevy_reflect`
### Changed
- `std::collections::HashSet` and `bevy_utils::hashbrown::HashSet` now
implement a more complete set of reflect functionalities instead of
"just" `reflect_value`
- `TypeInfo` contains a new variant `Set` that contains `SetInfo`
- `ReflectKind` contains a new variant `Set`
- `ReflectRef` contains a new variant `Set`
- `ReflectMut` contains a new variant `Set`
- `ReflectOwned` contains a new variant `Set`
## Migration Guide
- The new `Set` variants on the enums listed in the change section
should probably be considered by people working with this level of the
lib
### Help wanted!
I'm not sure if this change is able to break code. From my understanding
it shouldn't since we just add functionality but I'm not sure yet if
theres anything missing from my impl that would be normally provided by
`impl_reflect_value!`
# Objective
Many functions can be converted to `DynamicFunction` using
`IntoFunction`. Unfortunately, we are limited by Rust itself and the
implementations are far from exhaustive. For example, we can't convert
functions with more than 16 arguments. Additionally, we can't handle
returns with lifetimes not tied to the lifetime of the first argument.
In such cases, users will have to create their `DynamicFunction`
manually.
Let's take the following function:
```rust
fn get(index: usize, list: &Vec<String>) -> &String {
&list[index]
}
```
This function cannot be converted to a `DynamicFunction` via
`IntoFunction` due to the lifetime of the return value being tied to the
second argument. Therefore, we need to construct the `DynamicFunction`
manually:
```rust
DynamicFunction::new(
|mut args, info| {
let list = args
.pop()
.unwrap()
.take_ref::<Vec<String>>(&info.args()[1])?;
let index = args.pop().unwrap().take_owned::<usize>(&info.args()[0])?;
Ok(Return::Ref(get(index, list)))
},
FunctionInfo::new()
.with_name("get")
.with_args(vec![
ArgInfo:🆕:<usize>(0).with_name("index"),
ArgInfo:🆕:<&Vec<String>>(1).with_name("list"),
])
.with_return_info(ReturnInfo:🆕:<&String>()),
);
```
While still a small and straightforward snippet, there's a decent amount
going on here. There's a lot of room for improvements when it comes to
ergonomics and readability.
The goal of this PR is to address those issues.
## Solution
Improve the ergonomics and readability of manually created
`DynamicFunction`s.
Some of the major changes:
1. Removed the need for `&ArgInfo` when reifying arguments (i.e. the
`&info.args()[1]` calls)
2. Added additional `pop` methods on `ArgList` to handle both popping
and casting
3. Added `take` methods on `ArgList` for taking the arguments out in
order
4. Removed the need for `&FunctionInfo` in the internal closure (Change
1 made it no longer necessary)
5. Added methods to automatically handle generating `ArgInfo` and
`ReturnInfo`
With all these changes in place, we get something a lot nicer to both
write and look at:
```rust
DynamicFunction::new(
|mut args| {
let index = args.take::<usize>()?;
let list = args.take::<&Vec<String>>()?;
Ok(Return::Ref(get(index, list)))
},
FunctionInfo::new()
.with_name("get")
.with_arg::<usize>("index")
.with_arg::<&Vec<String>>("list")
.with_return::<&String>(),
);
```
Alternatively, to rely on type inference for taking arguments, you could
do:
```rust
DynamicFunction::new(
|mut args| {
let index = args.take_owned()?;
let list = args.take_ref()?;
Ok(Return::Ref(get(index, list)))
},
FunctionInfo::new()
.with_name("get")
.with_arg::<usize>("index")
.with_arg::<&Vec<String>>("list")
.with_return::<&String>(),
);
```
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Removed `&ArgInfo` argument from `FromArg::from_arg` trait method
- Removed `&ArgInfo` argument from `Arg::take_***` methods
- Added `ArgValue`
- `Arg` is now a struct containing an `ArgValue` and an argument `index`
- `Arg::take_***` methods now require `T` is also `TypePath`
- Added `Arg::new`, `Arg::index`, `Arg::value`, `Arg::take_value`, and
`Arg::take` methods
- Replaced `ArgId` in `ArgError` with just the argument `index`
- Added `ArgError::EmptyArgList`
- Renamed `ArgList::push` to `ArgList::push_arg`
- Added `ArgList::pop_arg`, `ArgList::pop_owned`, `ArgList::pop_ref`,
and `ArgList::pop_mut`
- Added `ArgList::take_arg`, `ArgList::take_owned`, `ArgList::take_ref`,
`ArgList::take_mut`, and `ArgList::take`
- `ArgList::pop` is now generic
- Renamed `FunctionError::InvalidArgCount` to
`FunctionError::ArgCountMismatch`
- The closure given to `DynamicFunction::new` no longer has a
`&FunctionInfo` argument
- Added `FunctionInfo::with_arg`
- Added `FunctionInfo::with_return`
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
* The `FromArg::from_arg` trait method and the `Arg::take_***` methods
no longer take a `&ArgInfo` argument.
* What used to be `Arg` is now `ArgValue`. `Arg` is now a struct which
contains an `ArgValue`.
* `Arg::take_***` methods now require `T` is also `TypePath`
* Instances of `id: ArgId` in `ArgError` have been replaced with `index:
usize`
* `ArgList::push` is now `ArgList::push_arg`. It also takes the new
`ArgValue` type.
* `ArgList::pop` has become `ArgList::pop_arg` and now returns
`ArgValue`. `Arg::pop` now takes a generic type and downcasts to that
type. It's recommended to use `ArgList::take` and friends instead since
they allow removing the arguments from the list in the order they were
pushed (rather than reverse order).
* `FunctionError::InvalidArgCount` is now
`FunctionError::ArgCountMismatch`
* The closure given to `DynamicFunction::new` no longer has a
`&FunctionInfo` argument. This argument can be removed.
# Objective
As mentioned in
[this](https://github.com/bevyengine/bevy/pull/13152#issuecomment-2198387297)
comment, creating a function registry (see #14098) is a bit difficult
due to the requirements of `DynamicFunction`. Internally, a
`DynamicFunction` contains a `Box<dyn FnMut>` (the function that reifies
reflected arguments and calls the actual function), which requires `&mut
self` in order to be called.
This means that users would require a mutable reference to the function
registry for it to be useful— which isn't great. And they can't clone
the `DynamicFunction` either because cloning an `FnMut` isn't really
feasible (wrapping it in an `Arc` would allow it to be cloned but we
wouldn't be able to call the clone since we need a mutable reference to
the `FnMut`, which we can't get with multiple `Arc`s still alive,
requiring us to also slap in a `Mutex`, which adds additional overhead).
And we don't want to just replace the `dyn FnMut` with `dyn Fn` as that
would prevent reflecting closures that mutate their environment.
Instead, we need to introduce a new type to split the requirements of
`DynamicFunction`.
## Solution
Introduce new types for representing closures.
Specifically, this PR introduces `DynamicClosure` and
`DynamicClosureMut`. Similar to how `IntoFunction` exists for
`DynamicFunction`, two new traits were introduced: `IntoClosure` and
`IntoClosureMut`.
Now `DynamicFunction` stores a `dyn Fn` with a `'static` lifetime.
`DynamicClosure` also uses a `dyn Fn` but has a lifetime, `'env`, tied
to its environment. `DynamicClosureMut` is most like the old
`DynamicFunction`, keeping the `dyn FnMut` and also typing its lifetime,
`'env`, to the environment
Here are some comparison tables:
| | `DynamicFunction` | `DynamicClosure` | `DynamicClosureMut` |
| - | ----------------- | ---------------- | ------------------- |
| Callable with `&self` | ✅ | ✅ | ❌ |
| Callable with `&mut self` | ✅ | ✅ | ✅ |
| Allows for non-`'static` lifetimes | ❌ | ✅ | ✅ |
| | `IntoFunction` | `IntoClosure` | `IntoClosureMut` |
| - | -------------- | ------------- | ---------------- |
| Convert `fn` functions | ✅ | ✅ | ✅ |
| Convert `fn` methods | ✅ | ✅ | ✅ |
| Convert anonymous functions | ✅ | ✅ | ✅ |
| Convert closures that capture immutable references | ❌ | ✅ | ✅ |
| Convert closures that capture mutable references | ❌ | ❌ | ✅ |
| Convert closures that capture owned values | ❌[^1] | ✅ | ✅ |
[^1]: Due to limitations in Rust, `IntoFunction` can't be implemented
for just functions (unless we forced users to manually coerce them to
function pointers first). So closures that meet the trait requirements
_can technically_ be converted into a `DynamicFunction` as well. To both
future-proof and reduce confusion, though, we'll just pretend like this
isn't a thing.
```rust
let mut list: Vec<i32> = vec![1, 2, 3];
// `replace` is a closure that captures a mutable reference to `list`
let mut replace = |index: usize, value: i32| -> i32 {
let old_value = list[index];
list[index] = value;
old_value
};
// Convert the closure into a dynamic closure using `IntoClosureMut::into_closure_mut`
let mut func: DynamicClosureMut = replace.into_closure_mut();
// Dynamically call the closure:
let args = ArgList::default().push_owned(1_usize).push_owned(-2_i32);
let value = func.call_once(args).unwrap().unwrap_owned();
// Check the result:
assert_eq!(value.take::<i32>().unwrap(), 2);
assert_eq!(list, vec![1, -2, 3]);
```
### `ReflectFn`/`ReflectFnMut`
To make extending the function reflection system easier (the blanket
impls for `IntoFunction`, `IntoClosure`, and `IntoClosureMut` are all
incredibly short), this PR generalizes callables with two new traits:
`ReflectFn` and `ReflectFnMut`.
These traits mimic `Fn` and `FnMut` but allow for being called via
reflection. In fact, their blanket implementations are identical save
for `ReflectFn` being implemented over `Fn` types and `ReflectFnMut`
being implemented over `FnMut` types.
And just as `Fn` is a subtrait of `FnMut`, `ReflectFn` is a subtrait of
`ReflectFnMut`. So anywhere that expects a `ReflectFnMut` can also be
given a `ReflectFn`.
To reiterate, these traits aren't 100% necessary. They were added in
purely for extensibility. If we decide to split things up differently or
add new traits/types in the future, then those changes should be much
simpler to implement.
### `TypedFunction`
Because of the split into `ReflectFn` and `ReflectFnMut`, we needed a
new way to access the function type information. This PR moves that
concept over into `TypedFunction`.
Much like `Typed`, this provides a way to access a function's
`FunctionInfo`.
By splitting this trait out, it helps to ensure the other traits are
focused on a single responsibility.
### Internal Macros
The original function PR (#13152) implemented `IntoFunction` using a
macro which was passed into an `all_tuples!` macro invocation. Because
we needed the same functionality for these new traits, this PR has
copy+pasted that code for `ReflectFn`, `ReflectFnMut`, and
`TypedFunction`— albeit with some differences between them.
Originally, I was going to try and macro-ify the impls and where clauses
such that we wouldn't have to straight up duplicate a lot of this logic.
However, aside from being more complex in general, autocomplete just
does not play nice with such heavily nested macros (tried in both
RustRover and VSCode). And both of those problems told me that it just
wasn't worth it: we need to ensure the crate is easily maintainable,
even at the cost of duplicating code.
So instead, I made sure to simplify the macro code by removing all
fully-qualified syntax and cutting the where clauses down to the bare
essentials, which helps to clean up a lot of the visual noise. I also
tried my best to document the macro logic in certain areas (I may even
add a bit more) to help with maintainability for future devs.
### Documentation
Documentation for this module was a bit difficult for me. So many of
these traits and types are very interconnected. And each trait/type has
subtle differences that make documenting it in a single place, like at
the module level, difficult to do cleanly. Describing the valid
signatures is also challenging to do well.
Hopefully what I have here is okay. I think I did an okay job, but let
me know if there any thoughts on ways to improve it. We can also move
such a task to a followup PR for more focused discussion.
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Added `DynamicClosure` struct
- Added `DynamicClosureMut` struct
- Added `IntoClosure` trait
- Added `IntoClosureMut` trait
- Added `ReflectFn` trait
- Added `ReflectFnMut` trait
- Added `TypedFunction` trait
- `IntoFunction` now only works for standard Rust functions
- `IntoFunction` no longer takes a lifetime parameter
- `DynamicFunction::call` now only requires `&self`
- Removed `DynamicFunction::call_once`
- Changed the `IntoReturn::into_return` signature to include a where
clause
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
### `IntoClosure`
`IntoFunction` now only works for standard Rust functions. Calling
`IntoFunction::into_function` on a closure that captures references to
its environment (either mutable or immutable), will no longer compile.
Instead, you will need to use either `IntoClosure::into_closure` to
create a `DynamicClosure` or `IntoClosureMut::into_closure_mut` to
create a `DynamicClosureMut`, depending on your needs:
```rust
let punct = String::from("!");
let print = |value: String| {
println!("{value}{punct}");
};
// BEFORE
let func: DynamicFunction = print.into_function();
// AFTER
let func: DynamicClosure = print.into_closure();
```
### `IntoFunction` lifetime
Additionally, `IntoFunction` no longer takes a lifetime parameter as it
always expects a `'static` lifetime. Usages will need to remove any
lifetime parameters:
```rust
// BEFORE
fn execute<'env, F: IntoFunction<'env, Marker>, Marker>(f: F) {/* ... */}
// AFTER
fn execute<F: IntoFunction<Marker>, Marker>(f: F) {/* ... */}
```
### `IntoReturn`
`IntoReturn::into_return` now has a where clause. Any manual
implementors will need to add this where clause to their implementation.
# Objective
The github action summary titles every compile test group as
`compile_fail_utils`.
## Solution
Manually specify group names for compile fail tests.
## Testing
- Wait for compile fail tests to run.
- Observe the generated summary.
# Objective
Implement FromIterator/IntoIterator for dynamic types where missing
Note:
- can't impl `IntoIterator` for `&Array` & co because of orphan rules
- `into_iter().collect()` is a no-op for `Vec`s because of
specialization
---
## Migration Guide
- Change `DynamicArray::from_vec` to `DynamicArray::from_iter`
# Objective
Right now, `TypeInfo` can be accessed directly from a type using either
`Typed::type_info` or `Reflect::get_represented_type_info`.
However, once that `TypeInfo` is accessed, any nested types must be
accessed via the `TypeRegistry`.
```rust
#[derive(Reflect)]
struct Foo {
bar: usize
}
let registry = TypeRegistry::default();
let TypeInfo::Struct(type_info) = Foo::type_info() else {
panic!("expected struct info");
};
let field = type_info.field("bar").unwrap();
let field_info = registry.get_type_info(field.type_id()).unwrap();
assert!(field_info.is::<usize>());;
```
## Solution
Enable nested types within a `TypeInfo` to be retrieved directly.
```rust
#[derive(Reflect)]
struct Foo {
bar: usize
}
let TypeInfo::Struct(type_info) = Foo::type_info() else {
panic!("expected struct info");
};
let field = type_info.field("bar").unwrap();
let field_info = field.type_info().unwrap();
assert!(field_info.is::<usize>());;
```
The particular implementation was chosen for two reasons.
Firstly, we can't just store `TypeInfo` inside another `TypeInfo`
directly. This is because some types are recursive and would result in a
deadlock when trying to create the `TypeInfo` (i.e. it has to create the
`TypeInfo` before it can use it, but it also needs the `TypeInfo` before
it can create it). Therefore, we must instead store the function so it
can be retrieved lazily.
I had considered also using a `OnceLock` or something to lazily cache
the info, but I figured we can look into optimizations later. The API
should remain the same with or without the `OnceLock`.
Secondly, a new wrapper trait had to be introduced: `MaybeTyped`. Like
`RegisterForReflection`, this trait is `#[doc(hidden)]` and only exists
so that we can properly handle dynamic type fields without requiring
them to implement `Typed`. We don't want dynamic types to implement
`Typed` due to the fact that it would make the return type
`Option<&'static TypeInfo>` for all types even though only the dynamic
types ever need to return `None` (see #6971 for details).
Users should never have to interact with this trait as it has a blanket
impl for all `Typed` types. And `Typed` is automatically implemented
when deriving `Reflect` (as it is required).
The one downside is we do need to return `Option<&'static TypeInfo>`
from all these new methods so that we can handle the dynamic cases. If
we didn't have to, we'd be able to get rid of the `Option` entirely. But
I think that's an okay tradeoff for this one part of the API, and keeps
the other APIs intact.
## Testing
This PR contains tests to verify everything works as expected. You can
test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
### Public Changes
- Added `ArrayInfo::item_info` method
- Added `NamedField::type_info` method
- Added `UnnamedField::type_info` method
- Added `ListInfo::item_info` method
- Added `MapInfo::key_info` method
- Added `MapInfo::value_info` method
- All active fields now have a `Typed` bound (remember that this is
automatically satisfied for all types that derive `Reflect`)
### Internal Changes
- Added `MaybeTyped` trait
## Migration Guide
All active fields for reflected types (including lists, maps, tuples,
etc.), must implement `Typed`. For the majority of users this won't have
any visible impact.
However, users implementing `Reflect` manually may need to update their
types to implement `Typed` if they weren't already.
Additionally, custom dynamic types will need to implement the new hidden
`MaybeTyped` trait.
# Objective
There are times when we might know the type of a `TypeInfo` ahead of
time. Or we may have already checked it one way or another.
In such cases, it's a bit cumbersome to have to pattern match every time
we want to access the nested info:
```rust
if let TypeInfo::List(info) = <Vec<i32>>::type_info() {
// ...
} else {
panic!("expected list info");
}
```
Ideally, there would be a way to simply perform the cast down to
`ListInfo` since we already know it will succeed.
Or even if we don't, perhaps we just want a cleaner way of exiting a
function early (i.e. with the `?` operator).
## Solution
Taking a bit from
[`mirror-mirror`](https://docs.rs/mirror-mirror/latest/mirror_mirror/struct.TypeDescriptor.html#implementations),
`TypeInfo` now has methods for attempting a cast into the variant's info
type.
```rust
let info = <Vec<i32>>::type_info().as_list().unwrap();
// ...
```
These new conversion methods return a `Result` where the error type is a
new `TypeInfoError` enum.
A `Result` was chosen as the return type over `Option` because if we do
choose to `unwrap` it, the error message will give us some indication of
what went wrong. In other words, it can truly replace those instances
where we were panicking in the `else` case.
### Open Questions
1. Should the error types instead be a struct? I chose an enum for
future-proofing, but right now it only has one error state.
Alternatively, we could make it a reflect-wide casting error so it could
be used for similar methods on `ReflectRef` and friends.
2. I was going to do it in a separate PR but should I just go ahead and
add similar methods to `ReflectRef`, `ReflectMut`, and `ReflectOwned`? 🤔
3. Should we name these `try_as_***` instead of `as_***` since they
return a `Result`?
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
### Added
- `TypeInfoError` enum
- `TypeInfo::kind` method
- `TypeInfo::as_struct` method
- `TypeInfo::as_tuple_struct` method
- `TypeInfo::as_tuple` method
- `TypeInfo::as_list` method
- `TypeInfo::as_array` method
- `TypeInfo::as_map` method
- `TypeInfo::as_enum` method
- `TypeInfo::as_value` method
- `VariantInfoError` enum
- `VariantInfo::variant_type` method
- `VariantInfo::as_unit_variant` method
- `VariantInfo::as_tuple_variant` method
- `VariantInfo::as_struct_variant` method
# Objective
Function reflection requires a lot of macro code generation in the form
of several `all_tuples!` invocations, as well as impls generated in the
`Reflect` derive macro.
Seeing as function reflection is currently a bit more niche, it makes
sense to gate it all behind a feature.
## Solution
Add a `functions` feature to `bevy_reflect`, which can be enabled in
Bevy using the `reflect_functions` feature.
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
That should ensure that everything still works with the feature
disabled.
To test with the feature on, you can run:
```
cargo test --package bevy_reflect --features functions
```
---
## Changelog
- Moved function reflection behind a Cargo feature
(`bevy/reflect_functions` and `bevy_reflect/functions`)
- Add `IntoFunction` export in `bevy_reflect::prelude`
## Internal Migration Guide
> [!important]
> Function reflection was introduced as part of the 0.15 dev cycle. This
migration guide was written for developers relying on `main` during this
cycle, and is not a breaking change coming from 0.14.
Function reflection is now gated behind a feature. To use function
reflection, enable the feature:
- If using `bevy_reflect` directly, enable the `functions` feature
- If using `bevy`, enable the `reflect_functions` feature
# Objective
- Bevy currently has lot of invalid intra-doc links, let's fix them!
- Also make CI test them, to avoid future regressions.
- Helps with #1983 (but doesn't fix it, as there could still be explicit
links to docs.rs that are broken)
## Solution
- Make `cargo r -p ci -- doc-check` check fail on warnings (could also
be changed to just some specific lints)
- Manually fix all the warnings (note that in some cases it was unclear
to me what the fix should have been, I'll try to highlight them in a
self-review)
# Objective
Fixes#14221
## Solution
Add indentation as suggested.
## Testing
Confirmed that
- This makes Clippy happy with rust beta
- Built docs visually look the same before/after
Bump version after release
This PR has been auto-generated
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François Mockers <mockersf@gmail.com>
# Objective
Looks like I accidentally disabled the reflection compile fail tests in
#13152. These should be re-enabled.
## Solution
Re-enable reflection compile fail tests.
## Testing
CI should pass. You can also test locally by navigating to
`crates/bevy_reflect/compile_fail/` and running:
```
cargo test --target-dir ../../../target
```
# Objective
We're able to reflect types sooooooo... why not functions?
The goal of this PR is to make functions callable within a dynamic
context, where type information is not readily available at compile
time.
For example, if we have a function:
```rust
fn add(left: i32, right: i32) -> i32 {
left + right
}
```
And two `Reflect` values we've already validated are `i32` types:
```rust
let left: Box<dyn Reflect> = Box::new(2_i32);
let right: Box<dyn Reflect> = Box::new(2_i32);
```
We should be able to call `add` with these values:
```rust
// ?????
let result: Box<dyn Reflect> = add.call_dynamic(left, right);
```
And ideally this wouldn't just work for functions, but methods and
closures too!
Right now, users have two options:
1. Manually parse the reflected data and call the function themselves
2. Rely on registered type data to handle the conversions for them
For a small function like `add`, this isn't too bad. But what about for
more complex functions? What about for many functions?
At worst, this process is error-prone. At best, it's simply tedious.
And this is assuming we know the function at compile time. What if we
want to accept a function dynamically and call it with our own
arguments?
It would be much nicer if `bevy_reflect` could alleviate some of the
problems here.
## Solution
Added function reflection!
This adds a `DynamicFunction` type to wrap a function dynamically. This
can be called with an `ArgList`, which is a dynamic list of
`Reflect`-containing `Arg` arguments. It returns a `FunctionResult`
which indicates whether or not the function call succeeded, returning a
`Reflect`-containing `Return` type if it did succeed.
Many functions can be converted into this `DynamicFunction` type thanks
to the `IntoFunction` trait.
Taking our previous `add` example, this might look something like
(explicit types added for readability):
```rust
fn add(left: i32, right: i32) -> i32 {
left + right
}
let mut function: DynamicFunction = add.into_function();
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
let result: Return = function.call(args).unwrap();
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
And it also works on closures:
```rust
let add = |left: i32, right: i32| left + right;
let mut function: DynamicFunction = add.into_function();
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
let result: Return = function.call(args).unwrap();
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
As well as methods:
```rust
#[derive(Reflect)]
struct Foo(i32);
impl Foo {
fn add(&mut self, value: i32) {
self.0 += value;
}
}
let mut foo = Foo(2);
let mut function: DynamicFunction = Foo::add.into_function();
let args: ArgList = ArgList::new().push_mut(&mut foo).push_owned(2_i32);
function.call(args).unwrap();
assert_eq!(foo.0, 4);
```
### Limitations
While this does cover many functions, it is far from a perfect system
and has quite a few limitations. Here are a few of the limitations when
using `IntoFunction`:
1. The lifetime of the return value is only tied to the lifetime of the
first argument (useful for methods). This means you can't have a
function like `(a: i32, b: &i32) -> &i32` without creating the
`DynamicFunction` manually.
2. Only 15 arguments are currently supported. If the first argument is a
(mutable) reference, this number increases to 16.
3. Manual implementations of `Reflect` will need to implement the new
`FromArg`, `GetOwnership`, and `IntoReturn` traits in order to be used
as arguments/return types.
And some limitations of `DynamicFunction` itself:
1. All arguments share the same lifetime, or rather, they will shrink to
the shortest lifetime.
2. Closures that capture their environment may need to have their
`DynamicFunction` dropped before accessing those variables again (there
is a `DynamicFunction::call_once` to make this a bit easier)
3. All arguments and return types must implement `Reflect`. While not a
big surprise coming from `bevy_reflect`, this implementation could
actually still work by swapping `Reflect` out with `Any`. Of course,
that makes working with the arguments and return values a bit harder.
4. Generic functions are not supported (unless they have been manually
monomorphized)
And general, reflection gotchas:
1. `&str` does not implement `Reflect`. Rather, `&'static str`
implements `Reflect` (the same is true for `&Path` and similar types).
This means that `&'static str` is considered an "owned" value for the
sake of generating arguments. Additionally, arguments and return types
containing `&str` will assume it's `&'static str`, which is almost never
the desired behavior. In these cases, the only solution (I believe) is
to use `&String` instead.
### Followup Work
This PR is the first of two PRs I intend to work on. The second PR will
aim to integrate this new function reflection system into the existing
reflection traits and `TypeInfo`. The goal would be to register and call
a reflected type's methods dynamically.
I chose not to do that in this PR since the diff is already quite large.
I also want the discussion for both PRs to be focused on their own
implementation.
Another followup I'd like to do is investigate allowing common container
types as a return type, such as `Option<&[mut] T>` and `Result<&[mut] T,
E>`. This would allow even more functions to opt into this system. I
chose to not include it in this one, though, for the same reasoning as
previously mentioned.
### Alternatives
One alternative I had considered was adding a macro to convert any
function into a reflection-based counterpart. The idea would be that a
struct that wraps the function would be created and users could specify
which arguments and return values should be `Reflect`. It could then be
called via a new `Function` trait.
I think that could still work, but it will be a fair bit more involved,
requiring some slightly more complex parsing. And it of course is a bit
more work for the user, since they need to create the type via macro
invocation.
It also makes registering these functions onto a type a bit more
complicated (depending on how it's implemented).
For now, I think this is a fairly simple, yet powerful solution that
provides the least amount of friction for users.
---
## Showcase
Bevy now adds support for storing and calling functions dynamically
using reflection!
```rust
// 1. Take a standard Rust function
fn add(left: i32, right: i32) -> i32 {
left + right
}
// 2. Convert it into a type-erased `DynamicFunction` using the `IntoFunction` trait
let mut function: DynamicFunction = add.into_function();
// 3. Define your arguments from reflected values
let args: ArgList = ArgList::new().push_owned(2_i32).push_owned(2_i32);
// 4. Call the function with your arguments
let result: Return = function.call(args).unwrap();
// 5. Extract the return value
let value: Box<dyn Reflect> = result.unwrap_owned();
assert_eq!(value.take::<i32>().unwrap(), 4);
```
## Changelog
#### TL;DR
- Added support for function reflection
- Added a new `Function Reflection` example:
ba727898f2/examples/reflection/function_reflection.rs (L1-L157)
#### Details
Added the following items:
- `ArgError` enum
- `ArgId` enum
- `ArgInfo` struct
- `ArgList` struct
- `Arg` enum
- `DynamicFunction` struct
- `FromArg` trait (derived with `derive(Reflect)`)
- `FunctionError` enum
- `FunctionInfo` struct
- `FunctionResult` alias
- `GetOwnership` trait (derived with `derive(Reflect)`)
- `IntoFunction` trait (with blanket implementation)
- `IntoReturn` trait (derived with `derive(Reflect)`)
- `Ownership` enum
- `ReturnInfo` struct
- `Return` enum
---------
Co-authored-by: Periwink <charlesbour@gmail.com>
# Objective
The error messages that appear when a value cannot be serialized or
deserialized via reflection could be slightly improved.
When one of these operations fails, some users are confused about how to
resolve the issue. I've spoken with a few who didn't know they could
register `ReflectSerialize` themselves. We should try to clarify this to
some degree in the error messages.
## Solution
Add some more detail to the error messages.
For example, replacing this:
```
Type 'core::ops::RangeInclusive<f32>' did not register ReflectSerialize
```
with this:
```
Type `core::ops::RangeInclusive<f32>` did not register the `ReflectSerialize` type data. For certain types, this may need to be registered manually using `register_type_data`
```
I also added a separate error message if the type was not registered in
the type registry at all:
```
Type `core::ops::RangeInclusive<f32>` is not registered in the type registry
```
## Testing
You can test locally by running:
```
cargo test --package bevy_reflect
```
---
## Changelog
- Added error message for missing type registration when serializing
reflect data
- Changed error message for missing `ReflectSerialize` registration when
serializing reflect data
- Changed error message for missing `ReflectDeserialize` registration
when deserializing reflect data
previously I worked on fixing issue #13646, back when the error message
did not include the type at all.
But that error message had room for improvement, so I included the
feedback of @alice-i-cecile and @MrGVSV.
The error message will now read `the given key (of type
bevy_reflect::tests::Foo) does not support hashing` or 'the given key
(of type bevy_reflect::DynamicStruct) does not support hashing' in case
of a dynamic struct that represents a hashable struct
i also added a new unit test for this new behaviour
(`reflect_map_no_hash_dynamic`).
Fixes#13646 (again)
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
If you try to add an object to the hashmap that is not capable of
hashing, the program panics. For easier debugging, the type for that
object should be included in the error message.
Fixes#13646.
## Solution
initially i tried calling std::any::type_name_of_val. this had the
problem that it would print something like dyn Box<dyn Reflect>, not
helpful. But since these objects all implement Reflect, i used
Reflect::type_path() instead. Previously, the error message was part of
a constant called HASH_ERROR. i changed that to a macro called
hash_error to print the type of that object more easily
## Testing
i adapted the unit test reflect_map_no_hash to expect the type in that
panic aswell
since this is my first contribution, please let me know if i have done
everything properly
# Objective
Fixes#13456
## Solution
Moved `bevy_math`'s `Reflect` impls from `bevy_reflect` to `bevy_math`.
### Quick note
I accidentally used the same commit message while resolving a merge
conflict (first time I had to resolve a conflict). Sorry about that.
# Objective
- Create a new 2D primitive, Rhombus, also knows as "Diamond Shape"
- Simplify the creation and handling of isometric projections
- Extend Bevy's arsenal of 2D primitives
## Testing
- New unit tests created in bevy_math/ primitives and bev_math/ bounding
- Tested translations, rotations, wireframe, bounding sphere, aabb and
creation parameters
---------
Co-authored-by: Luís Figueiredo <luispcfigueiredo@tecnico.ulisboa.pt>
# Objective
The `enum_utility` module contains the `get_variant_constructors`
function, which is used to generate token streams for constructing
enums. It's used for the `FromReflect::from_reflect` implementation and
the `Reflect::try_apply` implementation.
Due to the complexity of enums, this function is understandably a little
messy and difficult to extend.
## Solution
Clean up the `enum_utility` module.
Now "clean" is a bit subjective. I believe my solution is "cleaner" in
that the logic to generate the tokens are strictly coupled with the
intended usage. Because of this, `try_apply` is also no longer strictly
coupled with `from_reflect`.
This makes it easier to extend with new functionality, which is
something I'm doing in a future unrelated PR that I have based off this
one.
## Testing
There shouldn't be any testing required other than ensuring that the
project still builds and that CI passes.
# Objective
As work on the editor starts to ramp up, it might be nice to start
allowing types to specify custom attributes. These can be used to
provide certain functionality to fields, such as ranges or controlling
how data is displayed.
A good example of this can be seen in
[`bevy-inspector-egui`](https://github.com/jakobhellermann/bevy-inspector-egui)
with its
[`InspectorOptions`](https://docs.rs/bevy-inspector-egui/0.22.1/bevy_inspector_egui/struct.InspectorOptions.html):
```rust
#[derive(Reflect, Default, InspectorOptions)]
#[reflect(InspectorOptions)]
struct Slider {
#[inspector(min = 0.0, max = 1.0)]
value: f32,
}
```
Normally, as demonstrated in the example above, these attributes are
handled by a derive macro and stored in a corresponding `TypeData`
struct (i.e. `ReflectInspectorOptions`).
Ideally, we would have a good way of defining this directly via
reflection so that users don't need to create and manage a whole proc
macro just to allow these sorts of attributes.
And note that this doesn't have to just be for inspectors and editors.
It can be used for things done purely on the code side of things.
## Solution
Create a new method for storing attributes on fields via the `Reflect`
derive.
These custom attributes are stored in type info (e.g. `NamedField`,
`StructInfo`, etc.).
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(@0.0..=1.0)]
value: f64,
}
let TypeInfo::Struct(info) = Slider::type_info() else {
panic!("expected struct info");
};
let field = info.field("value").unwrap();
let range = field.get_attribute::<RangeInclusive<f64>>().unwrap();
assert_eq!(*range, 0.0..=1.0);
```
## TODO
- [x] ~~Bikeshed syntax~~ Went with a type-based approach, prefixed by
`@` for ease of parsing and flexibility
- [x] Add support for custom struct/tuple struct field attributes
- [x] Add support for custom enum variant field attributes
- [x] ~~Add support for custom enum variant attributes (maybe?)~~ ~~Will
require a larger refactor. Can be saved for a future PR if we really
want it.~~ Actually, we apparently still have support for variant
attributes despite not using them, so it was pretty easy to add lol.
- [x] Add support for custom container attributes
- [x] Allow custom attributes to store any reflectable value (not just
`Lit`)
- [x] ~~Store attributes in registry~~ This PR used to store these in
attributes in the registry, however, it has since switched over to
storing them in type info
- [x] Add example
## Bikeshedding
> [!note]
> This section was made for the old method of handling custom
attributes, which stored them by name (i.e. `some_attribute = 123`). The
PR has shifted away from that, to a more type-safe approach.
>
> This section has been left for reference.
There are a number of ways we can syntactically handle custom
attributes. Feel free to leave a comment on your preferred one! Ideally
we want one that is clear, readable, and concise since these will
potentially see _a lot_ of use.
Below is a small, non-exhaustive list of them. Note that the
`skip_serializing` reflection attribute is added to demonstrate how each
case plays with existing reflection attributes.
<details>
<summary>List</summary>
##### 1. `@(name = value)`
> The `@` was chosen to make them stand out from other attributes and
because the "at" symbol is a subtle pneumonic for "attribute". Of
course, other symbols could be used (e.g. `$`, `#`, etc.).
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(@(min = 0.0, max = 1.0), skip_serializing)]
#[[reflect(@(bevy_editor::hint = "Range: 0.0 to 1.0"))]
value: f32,
}
```
##### 2. `@name = value`
> This is my personal favorite.
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(@min = 0.0, @max = 1.0, skip_serializing)]
#[[reflect(@bevy_editor::hint = "Range: 0.0 to 1.0")]
value: f32,
}
```
##### 3. `custom_attr(name = value)`
> `custom_attr` can be anything. Other possibilities include `with` or
`tag`.
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(custom_attr(min = 0.0, max = 1.0), skip_serializing)]
#[[reflect(custom_attr(bevy_editor::hint = "Range: 0.0 to 1.0"))]
value: f32,
}
```
##### 4. `reflect_attr(name = value)`
```rust
#[derive(Reflect)]
struct Slider {
#[reflect(skip_serializing)]
#[reflect_attr(min = 0.0, max = 1.0)]
#[[reflect_attr(bevy_editor::hint = "Range: 0.0 to 1.0")]
value: f32,
}
```
</details>
---
## Changelog
- Added support for custom attributes on reflected types (i.e.
`#[reflect(@Foo::new("bar")]`)
# Objective
- Fixes#12377
## Solution
Added simple `#[diagnostic::on_unimplemented(...)]` attributes to some
critical public traits providing a more approachable initial error
message. Where appropriate, a `note` is added indicating that a `derive`
macro is available.
## Examples
<details>
<summary>Examples hidden for brevity</summary>
Below is a collection of examples showing the new error messages
produced by this change. In general, messages will start with a more
Bevy-centric error message (e.g., _`MyComponent` is not a `Component`_),
and a note directing the user to an available derive macro where
appropriate.
### Missing `#[derive(Resource)]`
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
struct MyResource;
fn main() {
App::new()
.insert_resource(MyResource)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `MyResource` is not a `Resource`
--> examples/app/empty.rs:7:26
|
7 | .insert_resource(MyResource)
| --------------- ^^^^^^^^^^ invalid `Resource`
| |
| required by a bound introduced by this call
|
= help: the trait `Resource` is not implemented for `MyResource`
= note: consider annotating `MyResource` with `#[derive(Resource)]`
= help: the following other types implement trait `Resource`:
AccessibilityRequested
ManageAccessibilityUpdates
bevy::bevy_a11y::Focus
DiagnosticsStore
FrameCount
bevy::prelude::State<S>
SystemInfo
bevy::prelude::Axis<T>
and 141 others
note: required by a bound in `bevy::prelude::App::insert_resource`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:419:31
|
419 | pub fn insert_resource<R: Resource>(&mut self, resource: R) -> &mut Self {
| ^^^^^^^^ required by this bound in `App::insert_resource`
```
</details>
### Putting A `QueryData` in a `QueryFilter` Slot
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
#[derive(Component)]
struct A;
#[derive(Component)]
struct B;
fn my_system(_query: Query<&A, &B>) {}
fn main() {
App::new()
.add_systems(Update, my_system)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `&B` is not a valid `Query` filter
--> examples/app/empty.rs:9:22
|
9 | fn my_system(_query: Query<&A, &B>) {}
| ^^^^^^^^^^^^^ invalid `Query` filter
|
= help: the trait `QueryFilter` is not implemented for `&B`
= help: the following other types implement trait `QueryFilter`:
With<T>
Without<T>
bevy::prelude::Or<()>
bevy::prelude::Or<(F0,)>
bevy::prelude::Or<(F0, F1)>
bevy::prelude::Or<(F0, F1, F2)>
bevy::prelude::Or<(F0, F1, F2, F3)>
bevy::prelude::Or<(F0, F1, F2, F3, F4)>
and 28 others
note: required by a bound in `bevy::prelude::Query`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\query.rs:349:51
|
349 | pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> {
| ^^^^^^^^^^^ required by this bound in `Query`
```
</details>
### Missing `#[derive(Component)]`
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
struct A;
fn my_system(mut commands: Commands) {
commands.spawn(A);
}
fn main() {
App::new()
.add_systems(Startup, my_system)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `A` is not a `Bundle`
--> examples/app/empty.rs:6:20
|
6 | commands.spawn(A);
| ----- ^ invalid `Bundle`
| |
| required by a bound introduced by this call
|
= help: the trait `bevy::prelude::Component` is not implemented for `A`, which is required by `A: Bundle`
= note: consider annotating `A` with `#[derive(Component)]` or `#[derive(Bundle)]`
= help: the following other types implement trait `Bundle`:
TransformBundle
SceneBundle
DynamicSceneBundle
AudioSourceBundle<Source>
SpriteBundle
SpriteSheetBundle
Text2dBundle
MaterialMesh2dBundle<M>
and 34 others
= note: required for `A` to implement `Bundle`
note: required by a bound in `bevy::prelude::Commands::<'w, 's>::spawn`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\commands\mod.rs:243:21
|
243 | pub fn spawn<T: Bundle>(&mut self, bundle: T) -> EntityCommands {
| ^^^^^^ required by this bound in `Commands::<'w, 's>::spawn`
```
</details>
### Missing `#[derive(Asset)]`
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
struct A;
fn main() {
App::new()
.init_asset::<A>()
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `A` is not an `Asset`
--> examples/app/empty.rs:7:23
|
7 | .init_asset::<A>()
| ---------- ^ invalid `Asset`
| |
| required by a bound introduced by this call
|
= help: the trait `Asset` is not implemented for `A`
= note: consider annotating `A` with `#[derive(Asset)]`
= help: the following other types implement trait `Asset`:
Font
AnimationGraph
DynamicScene
Scene
AudioSource
Pitch
bevy::bevy_gltf::Gltf
GltfNode
and 17 others
note: required by a bound in `init_asset`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_asset\src\lib.rs:307:22
|
307 | fn init_asset<A: Asset>(&mut self) -> &mut Self;
| ^^^^^ required by this bound in `AssetApp::init_asset`
```
</details>
### Mismatched Input and Output on System Piping
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
fn producer() -> u32 {
123
}
fn consumer(_: In<u16>) {}
fn main() {
App::new()
.add_systems(Update, producer.pipe(consumer))
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `fn(bevy::prelude::In<u16>) {consumer}` is not a valid system with input `u32` and output `_`
--> examples/app/empty.rs:11:44
|
11 | .add_systems(Update, producer.pipe(consumer))
| ---- ^^^^^^^^ invalid system
| |
| required by a bound introduced by this call
|
= help: the trait `bevy::prelude::IntoSystem<u32, _, _>` is not implemented for fn item `fn(bevy::prelude::In<u16>) {consumer}`
= note: expecting a system which consumes `u32` and produces `_`
note: required by a bound in `pipe`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\mod.rs:168:12
|
166 | fn pipe<B, Final, MarkerB>(self, system: B) -> PipeSystem<Self::System, B::System>
| ---- required by a bound in this associated function
167 | where
168 | B: IntoSystem<Out, Final, MarkerB>,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `IntoSystem::pipe`
```
</details>
### Missing Reflection
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
#[derive(Component)]
struct MyComponent;
fn main() {
App::new()
.register_type::<MyComponent>()
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `MyComponent` does not provide type registration information
--> examples/app/empty.rs:8:26
|
8 | .register_type::<MyComponent>()
| ------------- ^^^^^^^^^^^ the trait `GetTypeRegistration` is not implemented for `MyComponent`
| |
| required by a bound introduced by this call
|
= note: consider annotating `MyComponent` with `#[derive(Reflect)]`
= help: the following other types implement trait `GetTypeRegistration`:
bool
char
isize
i8
i16
i32
i64
i128
and 443 others
note: required by a bound in `bevy::prelude::App::register_type`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:619:29
|
619 | pub fn register_type<T: bevy_reflect::GetTypeRegistration>(&mut self) -> &mut Self {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::register_type`
```
</details>
### Missing `#[derive(States)]` Implementation
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
#[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Hash)]
enum AppState {
#[default]
Menu,
InGame {
paused: bool,
turbo: bool,
},
}
fn main() {
App::new()
.init_state::<AppState>()
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: the trait bound `AppState: FreelyMutableState` is not satisfied
--> examples/app/empty.rs:15:23
|
15 | .init_state::<AppState>()
| ---------- ^^^^^^^^ the trait `FreelyMutableState` is not implemented for `AppState`
| |
| required by a bound introduced by this call
|
= note: consider annotating `AppState` with `#[derive(States)]`
note: required by a bound in `bevy::prelude::App::init_state`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:282:26
|
282 | pub fn init_state<S: FreelyMutableState + FromWorld>(&mut self) -> &mut Self {
| ^^^^^^^^^^^^^^^^^^ required by this bound in `App::init_state`
```
</details>
### Adding a `System` with Unhandled Output
<details>
<summary>Example Code</summary>
```rust
use bevy::prelude::*;
fn producer() -> u32 {
123
}
fn main() {
App::new()
.add_systems(Update, consumer)
.run();
}
```
</details>
<details>
<summary>Error Generated</summary>
```error
error[E0277]: `fn() -> u32 {producer}` does not describe a valid system configuration
--> examples/app/empty.rs:9:30
|
9 | .add_systems(Update, producer)
| ----------- ^^^^^^^^ invalid system configuration
| |
| required by a bound introduced by this call
|
= help: the trait `IntoSystem<(), (), _>` is not implemented for fn item `fn() -> u32 {producer}`, which is required by `fn() -> u32 {producer}: IntoSystemConfigs<_>`
= help: the following other types implement trait `IntoSystemConfigs<Marker>`:
<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)> as IntoSystemConfigs<()>>
<NodeConfigs<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)>> as IntoSystemConfigs<()>>
<(S0,) as IntoSystemConfigs<(SystemConfigTupleMarker, P0)>>
<(S0, S1) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1)>>
<(S0, S1, S2) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2)>>
<(S0, S1, S2, S3) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3)>>
<(S0, S1, S2, S3, S4) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4)>>
<(S0, S1, S2, S3, S4, S5) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4, P5)>>
and 14 others
= note: required for `fn() -> u32 {producer}` to implement `IntoSystemConfigs<_>`
note: required by a bound in `bevy::prelude::App::add_systems`
--> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:342:23
|
339 | pub fn add_systems<M>(
| ----------- required by a bound in this associated function
...
342 | systems: impl IntoSystemConfigs<M>,
| ^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::add_systems`
```
</details>
</details>
## Testing
CI passed locally.
## Migration Guide
Upgrade to version 1.78 (or higher) of Rust.
## Future Work
- Currently, hints are not supported in this diagnostic. Ideally,
suggestions like _"consider using ..."_ would be in a hint rather than a
note, but that is the best option for now.
- System chaining and other `all_tuples!(...)`-based traits have bad
error messages due to the slightly different error message format.
---------
Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
# Objective
Fixes#13189
## Solution
To add the reflect impls I needed to make all the struct fields pub. I
don't think there's any harm for these types, but just a note for
review.
---------
Co-authored-by: Ben Harper <ben@tukom.org>
# Objective
As was pointed out in #13183, `bevy_mikktspace` is missing it's msrv
from it `Cargo.toml`. This promted me to check the msrv of every
`bevy_*` crate. Closes#13183.
## Solution
- Call `cargo check` with different rust versions on every bevy crate
until it doesn't complain.
- Write down the rust version `cargo check` started working.
## Testing
- Install `cargo-msrv`.
- Run `cargo msrv verify`.
- Rejoice.
---
## Changelog
Every published bevy crate now specifies a MSRV. If your rust toolchain
isn't at least version `1.77.0` You'll likely not be able to compile
most of bevy.
## Migration Guide
If your rust toolchain is bellow version`1.77.0, update.
# Objective
Fixes #13230
## Solution
Uses solution described in #13230
They mention a worry about adding a branch, but I'm not sure there is
one.
This code
```Rust
#[no_mangle]
pub fn next_if_some(num: i32, b: Option<bool>) -> i32 {
num + b.is_some() as i32
}
```
produces this assembly with opt-level 3
```asm
next_if_some:
xor eax, eax
cmp sil, 2
setne al
add eax, edi
ret
```
## Testing
Added test from #13230, tagged it as ignore as it is only useful in
release mode and very slow if you accidentally invoke it in debug mode.
---
## Changelog
Iterationg of ListIter will no longer overflow and wrap around
## Migration Guide
# Objective
Unblocks #11659.
Currently the `Reflect` derive macro has to go through a merge process
for each `#[reflect]`/`#[reflet_value]` attribute encountered on a
container type.
Not only is this a bit inefficient, but it also has a soft requirement
that we can compare attributes such that an error can be thrown on
duplicates, invalid states, etc.
While working on #11659 this proved to be challenging due to the fact
that `syn` types don't implement `PartialEq` or `Hash` without enabling
the `extra-traits` feature.
Ideally, we wouldn't have to enable another feature just to accommodate
this one use case.
## Solution
Removed `ContainerAttributes::merge`.
This was a fairly simple change as we could just have the parsing
functions take `&mut self` instead of returning `Self`.
## Testing
CI should build as there should be no user-facing change.
# Objective
Finish the `try_apply` implementation started in #6770 by @feyokorenhof.
Supersedes and closes#6770. Closes#6182
## Solution
Add `try_apply` to `Reflect` and implement it in all the places that
implement `Reflect`.
---
## Changelog
Added `try_apply` to `Reflect`.
---------
Co-authored-by: Feyo Korenhof <feyokorenhof@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
- Some of the "large" crates have sub-crates, usually for things such as
macros.
- For an example, see [`bevy_ecs_macros` at
`bevy_ecs/macros`](4f9f987099/crates/bevy_ecs/macros).
- The one crate that does not follow this convention is
[`bevy_reflect_derive`](4f9f987099/crates/bevy_reflect/bevy_reflect_derive),
which is in the `bevy_reflect/bevy_reflect_derive` folder and not
`bevy_reflect/derive` or `bevy_reflect/macros`.
## Solution
- Rename folder `bevy_reflect_derive` to `derive`.
- I chose to use `derive` instead of `macros` because the crate name
itself ends in `_derive`. (One of only two crates to actually use this
convention, funnily enough.)
## Testing
- Build and test `bevy_reflect` and `bevy_reflect_derive`.
- Apply the following patch to `publish.sh` to run it in `--dry-run`
mode, to test that the path has been successfully updated:
- If you have any security concerns about applying random diffs, feel
free to skip this step. Worst case scenario it fails and Cart has to
manually publish a few crates.
```bash
# Apply patch to make `publish.sh` *not* actually publish anything.
git apply path/to/foo.patch
# Make `publish.sh` executable.
chmod +x tools/publish.sh
# Execute `publish.sh`.
./tools/publish.sh
```
```patch
diff --git a/tools/publish.sh b/tools/publish.sh
index b020bad28..fbcc09281 100644
--- a/tools/publish.sh
+++ b/tools/publish.sh
@@ -49,7 +49,7 @@ crates=(
if [ -n "$(git status --porcelain)" ]; then
echo "You have local changes!"
- exit 1
+ # exit 1
fi
pushd crates
@@ -61,15 +61,15 @@ do
cp ../LICENSE-APACHE "$crate"
pushd "$crate"
git add LICENSE-MIT LICENSE-APACHE
- cargo publish --no-verify --allow-dirty
+ cargo publish --no-verify --allow-dirty --dry-run
popd
- sleep 20
+ # sleep 20
done
popd
echo "Publishing root crate"
-cargo publish --allow-dirty
+cargo publish --allow-dirty --dry-run
echo "Cleaning local state"
git reset HEAD --hard
```
---
## Changelog
- Moved `bevy_reflect_derive` from
`crates/bevy_reflect/bevy_reflect_derive` to
`crates/bevy_reflect/derive`.
# Objective
- Follow-up of #13184 :)
- We use `ui_test` to test compiler errors for our custom macros.
- There are four crates related to compile fail tests
- `bevy_ecs_compile_fail_tests`, `bevy_macros_compile_fail_tests`, and
`bevy_reflect_compile_fail_tests`, which actually test the macros.
-
[`bevy_compile_test_utils`](64c1c65783/crates/bevy_compile_test_utils),
which provides helpers and common patterns for these tests.
- All of these crates reside within the `crates` directory.
- This can be confusing, especially for newcomers. All of the other
folders in `crates` are actual published libraries, except for these 4.
## Solution
- Move all compile fail tests to a `compile_fail` folder under their
corresponding crate.
- E.g. `crates/bevy_ecs_compile_fail_tests` would be moved to
`crates/bevy_ecs/compile_fail`.
- Move `bevy_compile_test_utils` to `tools/compile_fail_utils`.
There are a few benefits to this approach:
1. An internal testing detail is less intrusive (and confusing) for
those who just want to browse the public Bevy interface.
2. Follows a pre-existing approach of organizing related crates inside a
larger crate's folder.
- See `bevy_gizmos/macros` for an example.
4. Makes consistent the terms `compile_test`, `compile_fail`, and
`compile_fail_test` in code. It's all just `compile_fail` now, because
we are specifically testing the error messages on compiler failures.
- To be clear it can still be referred to by these terms in comments and
speech, just the names of the crates and the CI command are now
consistent.
## Testing
Run the compile fail CI command:
```shell
cargo run -p ci -- compile-fail
```
If it still passes, then my refactor was successful.
# Objective
- `README.md` is a common file that usually gives an overview of the
folder it is in.
- When on <https://crates.io>, `README.md` is rendered as the main
description.
- Many crates in this repository are lacking `README.md` files, which
makes it more difficult to understand their purpose.
<img width="1552" alt="image"
src="https://github.com/bevyengine/bevy/assets/59022059/78ebf91d-b0c4-4b18-9874-365d6310640f">
- There are also a few inconsistencies with `README.md` files that this
PR and its follow-ups intend to fix.
## Solution
- Create a `README.md` file for all crates that do not have one.
- This file only contains the title of the crate (underscores removed,
proper capitalization, acronyms expanded) and the <https://shields.io>
badges.
- Remove the `readme` field in `Cargo.toml` for `bevy` and
`bevy_reflect`.
- This field is redundant because [Cargo automatically detects
`README.md`
files](https://doc.rust-lang.org/cargo/reference/manifest.html#the-readme-field).
The field is only there if you name it something else, like `INFO.md`.
- Fix capitalization of `bevy_utils`'s `README.md`.
- It was originally `Readme.md`, which is inconsistent with the rest of
the project.
- I created two commits renaming it to `README.md`, because Git appears
to be case-insensitive.
- Expand acronyms in title of `bevy_ptr` and `bevy_utils`.
- In the commit where I created all the new `README.md` files, I
preferred using expanded acronyms in the titles. (E.g. "Bevy Developer
Tools" instead of "Bevy Dev Tools".)
- This commit changes the title of existing `README.md` files to follow
the same scheme.
- I do not feel strongly about this change, please comment if you
disagree and I can revert it.
- Add <https://shields.io> badges to `bevy_time` and `bevy_transform`,
which are the only crates currently lacking them.
---
## Changelog
- Added `README.md` files to all crates missing it.
# Objective
- Update glam version requirement to latest version.
## Solution
- Updated `glam` version requirement from 0.25 to 0.27.
- Updated `encase` and `encase_derive_impl` version requirement from 0.7
to 0.8.
- Updated `hexasphere` version requirement from 10.0 to 12.0.
- Breaking changes from glam changelog:
- [0.26.0] Minimum Supported Rust Version bumped to 1.68.2 for impl
From<bool> for {f32,f64} support.
- [0.27.0] Changed implementation of vector fract method to match the
Rust implementation instead of the GLSL implementation, that is self -
self.trunc() instead of self - self.floor().
---
## Migration Guide
- When using `glam` exports, keep in mind that `vector` `fract()` method
now matches Rust implementation (that is `self - self.trunc()` instead
of `self - self.floor()`). If you want to use the GLSL implementation
you should now use `fract_gl()`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Make `Result<T, E>` implement Reflect such that it is an Enum rather
than a Value
- Fixes#13178
## Solution
- Use the correct macro
## Testing
- Did you test these changes?
I tried it out locally, and it does what it says on the tin. Not sure
how to test it in context of the crate?
---
## Changelog
### Changed
- Result now uses `ReflectKind::Enum` rather than `ReflectKind::Value`,
allowing for inspection of its constituents
## Migration Guide
`Result<T, E>` has had its `Reflect` implementation changed to align it
with `Option<T>` and its intended semantics: A carrier of either an `Ok`
or `Err` value, and the ability to access it. To achieve this it is no
longer a `ReflectKind::Value` but rather a `ReflectKind::Enum` and as
such carries these changes with it:
For `Result<T, E>`
- Both `T` and `E` no longer require to be `Clone` and now require to be
`FromReflect`
- `<Result<T, E> as Reflect>::reflect_*` now returns a
`ReflectKind::Enum`, so any code that previously relied on it being a
`Value` kind will have to be adapted.
- `Result<T, E>` now implements `Enum`
Since the migration is highly dependent on the previous usage, no
automatic upgrade path can be given.
Signed-off-by: Marcel Müller <neikos@neikos.email>
# Objective
- Provide a way to iterate over the registered TypeData.
## Solution
- a new method on the `TypeRegistry` that iterates over
`TypeRegistrations` with theirs `TypeData`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
`EntityHashSet` doesn't seem to implement `Reflect` which seems weird!
Especially since `EntityHashMap` implements `Reflect`.
This PR just added an extra `impl_reflect_value!` for `EntityHashSet`
and this seems to do the trick.
I left out doing the same for `StableHashSet` since it's marked as
deprecated.
---
I'm really wondering what was the issue here. If anyone can explain why
`EntityHashSet` can't use the `Reflect` impl of `bevy_utils::HashSet`
similar to how it's the case with the `...HashMap`s I'd be interested!
# Objective
- Fixes#12976
## Solution
This one is a doozy.
- Run `cargo +beta clippy --workspace --all-targets --all-features` and
fix all issues
- This includes:
- Moving inner attributes to be outer attributes, when the item in
question has both inner and outer attributes
- Use `ptr::from_ref` in more scenarios
- Extend the valid idents list used by `clippy:doc_markdown` with more
names
- Use `Clone::clone_from` when possible
- Remove redundant `ron` import
- Add backticks to **so many** identifiers and items
- I'm sorry whoever has to review this
---
## Changelog
- Added links to more identifiers in documentation.
# Objective
- I daily drive nightly Rust when developing Bevy, so I notice when new
warnings are raised by `cargo check` and Clippy.
- `cargo +nightly clippy` raises a few of these new warnings.
## Solution
- Fix most warnings from `cargo +nightly clippy`
- I skipped the docs-related warnings because some were covered by
#12692.
- Use `Clone::clone_from` in applicable scenarios, which can sometimes
avoid an extra allocation.
- Implement `Default` for structs that have a `pub const fn new() ->
Self` method.
- Fix an occurrence where generic constraints were defined in both `<C:
Trait>` and `where C: Trait`.
- Removed generic constraints that were implied by the `Bundle` trait.
---
## Changelog
- `BatchingStrategy`, `NonGenericTypeCell`, and `GenericTypeCell` now
implement `Default`.
