Enum ArgValue 

pub enum ArgValue<'a> {
    Owned(Box<dyn PartialReflect>),
    Ref(&'a (dyn PartialReflect + 'static)),
    Mut(&'a mut (dyn PartialReflect + 'static)),
}

Available on crate feature functions only.

Represents an argument that can be passed to a DynamicFunction or DynamicFunctionMut.

Variants

Owned(Box<dyn PartialReflect>)

An owned argument.

Ref(&'a (dyn PartialReflect + 'static))

An immutable reference argument.

Mut(&'a mut (dyn PartialReflect + 'static))

A mutable reference argument.

Methods from Deref<Target = dyn PartialReflect>

pub fn represents<T>(&self) -> bool

where T: Reflect + TypePath,

Returns true if the underlying value represents a value of type T, or false otherwise.

Read is for more information on underlying values and represented types.

Examples found in repository

examples/reflection/dynamic_types.rs (line 81)

fn main() {
    #[derive(Reflect, Default, PartialEq, Debug)]
    #[reflect(Identifiable, Default)]
    struct Player {
        id: u32,
    }

    #[reflect_trait]
    trait Identifiable {
        fn id(&self) -> u32;
    }

    impl Identifiable for Player {
        fn id(&self) -> u32 {
            self.id
        }
    }

    // Normally, when instantiating a type, you get back exactly that type.
    // This is because the type is known at compile time.
    // We call this the "concrete" or "canonical" type.
    let player: Player = Player { id: 123 };

    // When working with reflected types, however, we often "erase" this type information
    // using the `Reflect` trait object.
    // This trait object also gives us access to all the methods in the `PartialReflect` trait too.
    // The underlying type is still the same (in this case, `Player`),
    // but now we've hidden that information from the compiler.
    let reflected: Box<dyn Reflect> = Box::new(player);

    // Because it's the same type under the hood, we can still downcast it back to the original type.
    assert!(reflected.downcast_ref::<Player>().is_some());

    // We can attempt to clone our value using `PartialReflect::reflect_clone`.
    // This will recursively call `PartialReflect::reflect_clone` on all fields of the type.
    // Or, if we had registered `ReflectClone` using `#[reflect(Clone)]`, it would simply call `Clone::clone` directly.
    let cloned: Box<dyn Reflect> = reflected.reflect_clone().unwrap();
    assert_eq!(cloned.downcast_ref::<Player>(), Some(&Player { id: 123 }));

    // Another way we can "clone" our data is by converting it to a dynamic type.
    // Notice here we bind it as a `dyn PartialReflect` instead of `dyn Reflect`.
    // This is because it returns a dynamic type that simply represents the original type.
    // In this case, because `Player` is a struct, it will return a `DynamicStruct`.
    let dynamic: Box<dyn PartialReflect> = reflected.to_dynamic();
    assert!(dynamic.is_dynamic());

    // And if we try to convert it back to a `dyn Reflect` trait object, we'll get `None`.
    // Dynamic types cannot be directly cast to `dyn Reflect` trait objects.
    assert!(dynamic.try_as_reflect().is_none());

    // Generally dynamic types are used to represent (or "proxy") the original type,
    // so that we can continue to access its fields and overall structure.
    let dynamic_ref = dynamic.reflect_ref().as_struct().unwrap();
    let id = dynamic_ref.field("id").unwrap().try_downcast_ref::<u32>();
    assert_eq!(id, Some(&123));

    // It also enables us to create a representation of a type without having compile-time
    // access to the actual type. This is how the reflection deserializers work.
    // They generally can't know how to construct a type ahead of time,
    // so they instead build and return these dynamic representations.
    let input = "(id: 123)";
    let mut registry = TypeRegistry::default();
    registry.register::<Player>();
    let registration = registry.get(std::any::TypeId::of::<Player>()).unwrap();
    let deserialized = TypedReflectDeserializer::new(registration, &registry)
        .deserialize(&mut ron::Deserializer::from_str(input).unwrap())
        .unwrap();

    // Our deserialized output is a `DynamicStruct` that proxies/represents a `Player`.
    assert!(deserialized.represents::<Player>());

    // And while this does allow us to access the fields and structure of the type,
    // there may be instances where we need the actual type.
    // For example, if we want to convert our `dyn Reflect` into a `dyn Identifiable`,
    // we can't use the `DynamicStruct` proxy.
    let reflect_identifiable = registration
        .data::<ReflectIdentifiable>()
        .expect("`ReflectIdentifiable` should be registered");

    // Trying to access the registry with our `deserialized` will give a compile error
    // since it doesn't implement `Reflect`, only `PartialReflect`.
    // Similarly, trying to force the operation will fail.
    // This fails since the underlying type of `deserialized` is `DynamicStruct` and not `Player`.
    assert!(deserialized
        .try_as_reflect()
        .and_then(|reflect_trait_obj| reflect_identifiable.get(reflect_trait_obj))
        .is_none());

    // So how can we go from a dynamic type to a concrete type?
    // There are two ways:

    // 1. Using `PartialReflect::apply`.
    {
        // If you know the type at compile time, you can construct a new value and apply the dynamic
        // value to it.
        let mut value = Player::default();
        value.apply(deserialized.as_ref());
        assert_eq!(value.id, 123);

        // If you don't know the type at compile time, you need a dynamic way of constructing
        // an instance of the type. One such way is to use the `ReflectDefault` type data.
        let reflect_default = registration
            .data::<ReflectDefault>()
            .expect("`ReflectDefault` should be registered");

        let mut value: Box<dyn Reflect> = reflect_default.default();
        value.apply(deserialized.as_ref());

        let identifiable: &dyn Identifiable = reflect_identifiable.get(value.as_reflect()).unwrap();
        assert_eq!(identifiable.id(), 123);
    }

    // 2. Using `FromReflect`
    {
        // If you know the type at compile time, you can use the `FromReflect` trait to convert the
        // dynamic value into the concrete type directly.
        let value: Player = Player::from_reflect(deserialized.as_ref()).unwrap();
        assert_eq!(value.id, 123);

        // If you don't know the type at compile time, you can use the `ReflectFromReflect` type data
        // to perform the conversion dynamically.
        let reflect_from_reflect = registration
            .data::<ReflectFromReflect>()
            .expect("`ReflectFromReflect` should be registered");

        let value: Box<dyn Reflect> = reflect_from_reflect
            .from_reflect(deserialized.as_ref())
            .unwrap();
        let identifiable: &dyn Identifiable = reflect_identifiable.get(value.as_reflect()).unwrap();
        assert_eq!(identifiable.id(), 123);
    }

    // Lastly, while dynamic types are commonly generated via reflection methods like
    // `PartialReflect::to_dynamic` or via the reflection deserializers,
    // you can also construct them manually.
    let mut my_dynamic_list = DynamicList::from_iter([1u32, 2u32, 3u32]);

    // This is useful when you just need to apply some subset of changes to a type.
    let mut my_list: Vec<u32> = Vec::new();
    my_list.apply(&my_dynamic_list);
    assert_eq!(my_list, vec![1, 2, 3]);

    // And if you want it to actually proxy a type, you can configure it to do that as well:
    assert!(!my_dynamic_list
        .as_partial_reflect()
        .represents::<Vec<u32>>());
    my_dynamic_list.set_represented_type(Some(<Vec<u32>>::type_info()));
    assert!(my_dynamic_list
        .as_partial_reflect()
        .represents::<Vec<u32>>());

    // ============================= REFERENCE ============================= //
    // For reference, here are all the available dynamic types:

    // 1. `DynamicTuple`
    {
        let mut dynamic_tuple = DynamicTuple::default();
        dynamic_tuple.insert(1u32);
        dynamic_tuple.insert(2u32);
        dynamic_tuple.insert(3u32);

        let mut my_tuple: (u32, u32, u32) = (0, 0, 0);
        my_tuple.apply(&dynamic_tuple);
        assert_eq!(my_tuple, (1, 2, 3));
    }

    // 2. `DynamicArray`
    {
        let dynamic_array = DynamicArray::from_iter([1u32, 2u32, 3u32]);

        let mut my_array = [0u32; 3];
        my_array.apply(&dynamic_array);
        assert_eq!(my_array, [1, 2, 3]);
    }

    // 3. `DynamicList`
    {
        let dynamic_list = DynamicList::from_iter([1u32, 2u32, 3u32]);

        let mut my_list: Vec<u32> = Vec::new();
        my_list.apply(&dynamic_list);
        assert_eq!(my_list, vec![1, 2, 3]);
    }

    // 4. `DynamicSet`
    {
        let mut dynamic_set = DynamicSet::from_iter(["x", "y", "z"]);
        assert!(dynamic_set.contains(&"x"));

        dynamic_set.remove(&"y");

        let mut my_set: HashSet<&str> = HashSet::default();
        my_set.apply(&dynamic_set);
        assert_eq!(my_set, HashSet::from_iter(["x", "z"]));
    }

    // 5. `DynamicMap`
    {
        let dynamic_map = DynamicMap::from_iter([("x", 1u32), ("y", 2u32), ("z", 3u32)]);

        let mut my_map: HashMap<&str, u32> = HashMap::default();
        my_map.apply(&dynamic_map);
        assert_eq!(my_map.get("x"), Some(&1));
        assert_eq!(my_map.get("y"), Some(&2));
        assert_eq!(my_map.get("z"), Some(&3));
    }

    // 6. `DynamicStruct`
    {
        #[derive(Reflect, Default, Debug, PartialEq)]
        struct MyStruct {
            x: u32,
            y: u32,
            z: u32,
        }

        let mut dynamic_struct = DynamicStruct::default();
        dynamic_struct.insert("x", 1u32);
        dynamic_struct.insert("y", 2u32);
        dynamic_struct.insert("z", 3u32);

        let mut my_struct = MyStruct::default();
        my_struct.apply(&dynamic_struct);
        assert_eq!(my_struct, MyStruct { x: 1, y: 2, z: 3 });
    }

    // 7. `DynamicTupleStruct`
    {
        #[derive(Reflect, Default, Debug, PartialEq)]
        struct MyTupleStruct(u32, u32, u32);

        let mut dynamic_tuple_struct = DynamicTupleStruct::default();
        dynamic_tuple_struct.insert(1u32);
        dynamic_tuple_struct.insert(2u32);
        dynamic_tuple_struct.insert(3u32);

        let mut my_tuple_struct = MyTupleStruct::default();
        my_tuple_struct.apply(&dynamic_tuple_struct);
        assert_eq!(my_tuple_struct, MyTupleStruct(1, 2, 3));
    }

    // 8. `DynamicEnum`
    {
        #[derive(Reflect, Default, Debug, PartialEq)]
        enum MyEnum {
            #[default]
            Empty,
            Xyz(u32, u32, u32),
        }

        let mut values = DynamicTuple::default();
        values.insert(1u32);
        values.insert(2u32);
        values.insert(3u32);

        let dynamic_variant = DynamicVariant::Tuple(values);
        let dynamic_enum = DynamicEnum::new("Xyz", dynamic_variant);

        let mut my_enum = MyEnum::default();
        my_enum.apply(&dynamic_enum);
        assert_eq!(my_enum, MyEnum::Xyz(1, 2, 3));
    }
}

pub fn try_downcast_ref<T>(&self) -> Option<&T>

where T: Any,

Downcasts the value to type T by reference.

If the underlying value does not implement Reflect or is not of type T, returns None.

For remote types, T should be the type itself rather than the wrapper type.

Examples found in repository

examples/reflection/reflection_types.rs (line 49)

#[reflect(Hash, PartialEq, Clone)]
pub struct E {
    x: usize,
}

/// By default, deriving with Reflect assumes the type is either a "struct" or an "enum".
///
/// You can tell reflect to treat your type instead as an "opaque type" by using the `#[reflect(opaque)]`.
/// It is generally a good idea to implement (and reflect) the `PartialEq` and `Clone` (optionally also `Serialize` and `Deserialize`)
/// traits on opaque types to ensure that these values behave as expected when nested in other reflected types.
#[derive(Reflect, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
#[reflect(opaque)]
#[reflect(PartialEq

examples/reflection/function_reflection.rs (line 162)

fn main() {
    // There are times when it may be helpful to store a function away for later.
    // In Rust, we can do this by storing either a function pointer or a function trait object.
    // For example, say we wanted to store the following function:
    fn add(left: i32, right: i32) -> i32 {
        left + right
    }

    // We could store it as either of the following:
    let fn_pointer: fn(i32, i32) -> i32 = add;
    let fn_trait_object: Box<dyn Fn(i32, i32) -> i32> = Box::new(add);

    // And we can call them like so:
    let result = fn_pointer(2, 2);
    assert_eq!(result, 4);
    let result = fn_trait_object(2, 2);
    assert_eq!(result, 4);

    // However, you'll notice that we have to know the types of the arguments and return value at compile time.
    // This means there's not really a way to store or call these functions dynamically at runtime.
    // Luckily, Bevy's reflection crate comes with a set of tools for doing just that!
    // We do this by first converting our function into the reflection-based `DynamicFunction` type
    // using the `IntoFunction` trait.
    let function: DynamicFunction<'static> = dbg!(add.into_function());

    // This time, you'll notice that `DynamicFunction` doesn't take any information about the function's arguments or return value.
    // This is because `DynamicFunction` checks the types of the arguments and return value at runtime.
    // Now we can generate a list of arguments:
    let args: ArgList = dbg!(ArgList::new().with_owned(2_i32).with_owned(2_i32));

    // And finally, we can call the function.
    // This returns a `Result` indicating whether the function was called successfully.
    // For now, we'll just unwrap it to get our `Return` value,
    // which is an enum containing the function's return value.
    let return_value: Return = dbg!(function.call(args).unwrap());

    // The `Return` value can be pattern matched or unwrapped to get the underlying reflection data.
    // For the sake of brevity, we'll just unwrap it here and downcast it to the expected type of `i32`.
    let value: Box<dyn PartialReflect> = return_value.unwrap_owned();
    assert_eq!(value.try_take::<i32>().unwrap(), 4);

    // The same can also be done for closures that capture references to their environment.
    // Closures that capture their environment immutably can be converted into a `DynamicFunction`
    // using the `IntoFunction` trait.
    let minimum = 5;
    let clamp = |value: i32| value.max(minimum);

    let function: DynamicFunction = dbg!(clamp.into_function());
    let args = dbg!(ArgList::new().with_owned(2_i32));
    let return_value = dbg!(function.call(args).unwrap());
    let value: Box<dyn PartialReflect> = return_value.unwrap_owned();
    assert_eq!(value.try_take::<i32>().unwrap(), 5);

    // We can also handle closures that capture their environment mutably
    // using the `IntoFunctionMut` trait.
    let mut count = 0;
    let increment = |amount: i32| count += amount;

    let closure: DynamicFunctionMut = dbg!(increment.into_function_mut());
    let args = dbg!(ArgList::new().with_owned(5_i32));

    // Because `DynamicFunctionMut` mutably borrows `total`,
    // it will need to be dropped before `total` can be accessed again.
    // This can be done manually with `drop(closure)` or by using the `DynamicFunctionMut::call_once` method.
    dbg!(closure.call_once(args).unwrap());
    assert_eq!(count, 5);

    // Generic functions can also be converted into a `DynamicFunction`,
    // however, they will need to be manually monomorphized first.
    fn stringify<T: ToString>(value: T) -> String {
        value.to_string()
    }

    // We have to manually specify the concrete generic type we want to use.
    let function = stringify::<i32>.into_function();

    let args = ArgList::new().with_owned(123_i32);
    let return_value = function.call(args).unwrap();
    let value: Box<dyn PartialReflect> = return_value.unwrap_owned();
    assert_eq!(value.try_take::<String>().unwrap(), "123");

    // To make things a little easier, we can also "overload" functions.
    // This makes it so that a single `DynamicFunction` can represent multiple functions,
    // and the correct one is chosen based on the types of the arguments.
    // Each function overload must have a unique argument signature.
    let function = stringify::<i32>
        .into_function()
        .with_overload(stringify::<f32>);

    // Now our `function` accepts both `i32` and `f32` arguments.
    let args = ArgList::new().with_owned(1.23_f32);
    let return_value = function.call(args).unwrap();
    let value: Box<dyn PartialReflect> = return_value.unwrap_owned();
    assert_eq!(value.try_take::<String>().unwrap(), "1.23");

    // Function overloading even allows us to have a variable number of arguments.
    let function = (|| 0)
        .into_function()
        .with_overload(|a: i32| a)
        .with_overload(|a: i32, b: i32| a + b)
        .with_overload(|a: i32, b: i32, c: i32| a + b + c);

    let args = ArgList::new()
        .with_owned(1_i32)
        .with_owned(2_i32)
        .with_owned(3_i32);
    let return_value = function.call(args).unwrap();
    let value: Box<dyn PartialReflect> = return_value.unwrap_owned();
    assert_eq!(value.try_take::<i32>().unwrap(), 6);

    // As stated earlier, `IntoFunction` works for many kinds of simple functions.
    // Functions with non-reflectable arguments or return values may not be able to be converted.
    // Generic functions are also not supported (unless manually monomorphized like `foo::<i32>.into_function()`).
    // Additionally, the lifetime of the return value is tied to the lifetime of the first argument.
    // However, this means that many methods (i.e. functions with a `self` parameter) are also supported:
    #[derive(Reflect, Default)]
    struct Data {
        value: String,
    }

    impl Data {
        fn set_value(&mut self, value: String) {
            self.value = value;
        }

        // Note that only `&'static str` implements `Reflect`.
        // To get around this limitation we can use `&String` instead.
        fn get_value(&self) -> &String {
            &self.value
        }
    }

    let mut data = Data::default();

    let set_value = dbg!(Data::set_value.into_function());
    let args = dbg!(ArgList::new().with_mut(&mut data)).with_owned(String::from("Hello, world!"));
    dbg!(set_value.call(args).unwrap());
    assert_eq!(data.value, "Hello, world!");

    let get_value = dbg!(Data::get_value.into_function());
    let args = dbg!(ArgList::new().with_ref(&data));
    let return_value = dbg!(get_value.call(args).unwrap());
    let value: &dyn PartialReflect = return_value.unwrap_ref();
    assert_eq!(value.try_downcast_ref::<String>().unwrap(), "Hello, world!");

    // For more complex use cases, you can always create a custom `DynamicFunction` manually.
    // This is useful for functions that can't be converted via the `IntoFunction` trait.
    // For example, this function doesn't implement `IntoFunction` due to the fact that
    // the lifetime of the return value is not tied to the lifetime of the first argument.
    fn get_or_insert(value: i32, container: &mut Option<i32>) -> &i32 {
        if container.is_none() {
            *container = Some(value);
        }

        container.as_ref().unwrap()
    }

    let get_or_insert_function = dbg!(DynamicFunction::new(
        |mut args: ArgList| -> FunctionResult {
            // The `ArgList` contains the arguments in the order they were pushed.
            // The `DynamicFunction` will validate that the list contains
            // exactly the number of arguments we expect.
            // We can retrieve them out in order (note that this modifies the `ArgList`):
            let value = args.take::<i32>()?;
            let container = args.take::<&mut Option<i32>>()?;

            // We could have also done the following to make use of type inference:
            // let value = args.take_owned()?;
            // let container = args.take_mut()?;

            Ok(Return::Ref(get_or_insert(value, container)))
        },
        // Functions can be either anonymous or named.
        // It's good practice, though, to try and name your functions whenever possible.
        // This makes it easier to debug and is also required for function registration.
        // We can either give it a custom name or use the function's type name as
        // derived from `std::any::type_name_of_val`.
        SignatureInfo::named(std::any::type_name_of_val(&get_or_insert))
            // We can always change the name if needed.
            // It's a good idea to also ensure that the name is unique,
            // such as by using its type name or by prefixing it with your crate name.
            .with_name("my_crate::get_or_insert")
            // Since our function takes arguments, we should provide that argument information.
            // This is used to validate arguments when calling the function.
            // And it aids consumers of the function with their own validation and debugging.
            // Arguments should be provided in the order they are defined in the function.
            .with_arg::<i32>("value")
            .with_arg::<&mut Option<i32>>("container")
            // We can provide return information as well.
            .with_return::<&i32>(),
    ));

    let mut container: Option<i32> = None;

    let args = dbg!(ArgList::new().with_owned(5_i32).with_mut(&mut container));
    let value = dbg!(get_or_insert_function.call(args).unwrap()).unwrap_ref();
    assert_eq!(value.try_downcast_ref::<i32>(), Some(&5));

    let args = dbg!(ArgList::new().with_owned(500_i32).with_mut(&mut container));
    let value = dbg!(get_or_insert_function.call(args).unwrap()).unwrap_ref();
    assert_eq!(value.try_downcast_ref::<i32>(), Some(&5));
}

examples/reflection/dynamic_types.rs (line 65)

fn main() {
    #[derive(Reflect, Default, PartialEq, Debug)]
    #[reflect(Identifiable, Default)]
    struct Player {
        id: u32,
    }

    #[reflect_trait]
    trait Identifiable {
        fn id(&self) -> u32;
    }

    impl Identifiable for Player {
        fn id(&self) -> u32 {
            self.id
        }
    }

    // Normally, when instantiating a type, you get back exactly that type.
    // This is because the type is known at compile time.
    // We call this the "concrete" or "canonical" type.
    let player: Player = Player { id: 123 };

    // When working with reflected types, however, we often "erase" this type information
    // using the `Reflect` trait object.
    // This trait object also gives us access to all the methods in the `PartialReflect` trait too.
    // The underlying type is still the same (in this case, `Player`),
    // but now we've hidden that information from the compiler.
    let reflected: Box<dyn Reflect> = Box::new(player);

    // Because it's the same type under the hood, we can still downcast it back to the original type.
    assert!(reflected.downcast_ref::<Player>().is_some());

    // We can attempt to clone our value using `PartialReflect::reflect_clone`.
    // This will recursively call `PartialReflect::reflect_clone` on all fields of the type.
    // Or, if we had registered `ReflectClone` using `#[reflect(Clone)]`, it would simply call `Clone::clone` directly.
    let cloned: Box<dyn Reflect> = reflected.reflect_clone().unwrap();
    assert_eq!(cloned.downcast_ref::<Player>(), Some(&Player { id: 123 }));

    // Another way we can "clone" our data is by converting it to a dynamic type.
    // Notice here we bind it as a `dyn PartialReflect` instead of `dyn Reflect`.
    // This is because it returns a dynamic type that simply represents the original type.
    // In this case, because `Player` is a struct, it will return a `DynamicStruct`.
    let dynamic: Box<dyn PartialReflect> = reflected.to_dynamic();
    assert!(dynamic.is_dynamic());

    // And if we try to convert it back to a `dyn Reflect` trait object, we'll get `None`.
    // Dynamic types cannot be directly cast to `dyn Reflect` trait objects.
    assert!(dynamic.try_as_reflect().is_none());

    // Generally dynamic types are used to represent (or "proxy") the original type,
    // so that we can continue to access its fields and overall structure.
    let dynamic_ref = dynamic.reflect_ref().as_struct().unwrap();
    let id = dynamic_ref.field("id").unwrap().try_downcast_ref::<u32>();
    assert_eq!(id, Some(&123));

    // It also enables us to create a representation of a type without having compile-time
    // access to the actual type. This is how the reflection deserializers work.
    // They generally can't know how to construct a type ahead of time,
    // so they instead build and return these dynamic representations.
    let input = "(id: 123)";
    let mut registry = TypeRegistry::default();
    registry.register::<Player>();
    let registration = registry.get(std::any::TypeId::of::<Player>()).unwrap();
    let deserialized = TypedReflectDeserializer::new(registration, &registry)
        .deserialize(&mut ron::Deserializer::from_str(input).unwrap())
        .unwrap();

    // Our deserialized output is a `DynamicStruct` that proxies/represents a `Player`.
    assert!(deserialized.represents::<Player>());

    // And while this does allow us to access the fields and structure of the type,
    // there may be instances where we need the actual type.
    // For example, if we want to convert our `dyn Reflect` into a `dyn Identifiable`,
    // we can't use the `DynamicStruct` proxy.
    let reflect_identifiable = registration
        .data::<ReflectIdentifiable>()
        .expect("`ReflectIdentifiable` should be registered");

    // Trying to access the registry with our `deserialized` will give a compile error
    // since it doesn't implement `Reflect`, only `PartialReflect`.
    // Similarly, trying to force the operation will fail.
    // This fails since the underlying type of `deserialized` is `DynamicStruct` and not `Player`.
    assert!(deserialized
        .try_as_reflect()
        .and_then(|reflect_trait_obj| reflect_identifiable.get(reflect_trait_obj))
        .is_none());

    // So how can we go from a dynamic type to a concrete type?
    // There are two ways:

    // 1. Using `PartialReflect::apply`.
    {
        // If you know the type at compile time, you can construct a new value and apply the dynamic
        // value to it.
        let mut value = Player::default();
        value.apply(deserialized.as_ref());
        assert_eq!(value.id, 123);

        // If you don't know the type at compile time, you need a dynamic way of constructing
        // an instance of the type. One such way is to use the `ReflectDefault` type data.
        let reflect_default = registration
            .data::<ReflectDefault>()
            .expect("`ReflectDefault` should be registered");

        let mut value: Box<dyn Reflect> = reflect_default.default();
        value.apply(deserialized.as_ref());

        let identifiable: &dyn Identifiable = reflect_identifiable.get(value.as_reflect()).unwrap();
        assert_eq!(identifiable.id(), 123);
    }

    // 2. Using `FromReflect`
    {
        // If you know the type at compile time, you can use the `FromReflect` trait to convert the
        // dynamic value into the concrete type directly.
        let value: Player = Player::from_reflect(deserialized.as_ref()).unwrap();
        assert_eq!(value.id, 123);

        // If you don't know the type at compile time, you can use the `ReflectFromReflect` type data
        // to perform the conversion dynamically.
        let reflect_from_reflect = registration
            .data::<ReflectFromReflect>()
            .expect("`ReflectFromReflect` should be registered");

        let value: Box<dyn Reflect> = reflect_from_reflect
            .from_reflect(deserialized.as_ref())
            .unwrap();
        let identifiable: &dyn Identifiable = reflect_identifiable.get(value.as_reflect()).unwrap();
        assert_eq!(identifiable.id(), 123);
    }

    // Lastly, while dynamic types are commonly generated via reflection methods like
    // `PartialReflect::to_dynamic` or via the reflection deserializers,
    // you can also construct them manually.
    let mut my_dynamic_list = DynamicList::from_iter([1u32, 2u32, 3u32]);

    // This is useful when you just need to apply some subset of changes to a type.
    let mut my_list: Vec<u32> = Vec::new();
    my_list.apply(&my_dynamic_list);
    assert_eq!(my_list, vec![1, 2, 3]);

    // And if you want it to actually proxy a type, you can configure it to do that as well:
    assert!(!my_dynamic_list
        .as_partial_reflect()
        .represents::<Vec<u32>>());
    my_dynamic_list.set_represented_type(Some(<Vec<u32>>::type_info()));
    assert!(my_dynamic_list
        .as_partial_reflect()
        .represents::<Vec<u32>>());

    // ============================= REFERENCE ============================= //
    // For reference, here are all the available dynamic types:

    // 1. `DynamicTuple`
    {
        let mut dynamic_tuple = DynamicTuple::default();
        dynamic_tuple.insert(1u32);
        dynamic_tuple.insert(2u32);
        dynamic_tuple.insert(3u32);

        let mut my_tuple: (u32, u32, u32) = (0, 0, 0);
        my_tuple.apply(&dynamic_tuple);
        assert_eq!(my_tuple, (1, 2, 3));
    }

    // 2. `DynamicArray`
    {
        let dynamic_array = DynamicArray::from_iter([1u32, 2u32, 3u32]);

        let mut my_array = [0u32; 3];
        my_array.apply(&dynamic_array);
        assert_eq!(my_array, [1, 2, 3]);
    }

    // 3. `DynamicList`
    {
        let dynamic_list = DynamicList::from_iter([1u32, 2u32, 3u32]);

        let mut my_list: Vec<u32> = Vec::new();
        my_list.apply(&dynamic_list);
        assert_eq!(my_list, vec![1, 2, 3]);
    }

    // 4. `DynamicSet`
    {
        let mut dynamic_set = DynamicSet::from_iter(["x", "y", "z"]);
        assert!(dynamic_set.contains(&"x"));

        dynamic_set.remove(&"y");

        let mut my_set: HashSet<&str> = HashSet::default();
        my_set.apply(&dynamic_set);
        assert_eq!(my_set, HashSet::from_iter(["x", "z"]));
    }

    // 5. `DynamicMap`
    {
        let dynamic_map = DynamicMap::from_iter([("x", 1u32), ("y", 2u32), ("z", 3u32)]);

        let mut my_map: HashMap<&str, u32> = HashMap::default();
        my_map.apply(&dynamic_map);
        assert_eq!(my_map.get("x"), Some(&1));
        assert_eq!(my_map.get("y"), Some(&2));
        assert_eq!(my_map.get("z"), Some(&3));
    }

    // 6. `DynamicStruct`
    {
        #[derive(Reflect, Default, Debug, PartialEq)]
        struct MyStruct {
            x: u32,
            y: u32,
            z: u32,
        }

        let mut dynamic_struct = DynamicStruct::default();
        dynamic_struct.insert("x", 1u32);
        dynamic_struct.insert("y", 2u32);
        dynamic_struct.insert("z", 3u32);

        let mut my_struct = MyStruct::default();
        my_struct.apply(&dynamic_struct);
        assert_eq!(my_struct, MyStruct { x: 1, y: 2, z: 3 });
    }

    // 7. `DynamicTupleStruct`
    {
        #[derive(Reflect, Default, Debug, PartialEq)]
        struct MyTupleStruct(u32, u32, u32);

        let mut dynamic_tuple_struct = DynamicTupleStruct::default();
        dynamic_tuple_struct.insert(1u32);
        dynamic_tuple_struct.insert(2u32);
        dynamic_tuple_struct.insert(3u32);

        let mut my_tuple_struct = MyTupleStruct::default();
        my_tuple_struct.apply(&dynamic_tuple_struct);
        assert_eq!(my_tuple_struct, MyTupleStruct(1, 2, 3));
    }

    // 8. `DynamicEnum`
    {
        #[derive(Reflect, Default, Debug, PartialEq)]
        enum MyEnum {
            #[default]
            Empty,
            Xyz(u32, u32, u32),
        }

        let mut values = DynamicTuple::default();
        values.insert(1u32);
        values.insert(2u32);
        values.insert(3u32);

        let dynamic_variant = DynamicVariant::Tuple(values);
        let dynamic_enum = DynamicEnum::new("Xyz", dynamic_variant);

        let mut my_enum = MyEnum::default();
        my_enum.apply(&dynamic_enum);
        assert_eq!(my_enum, MyEnum::Xyz(1, 2, 3));
    }
}

Trait Implementations

impl<'a> Debug for ArgValue<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'a> Deref for ArgValue<'a>

type Target = dyn PartialReflect

The resulting type after dereferencing.

fn deref(&self) -> &<ArgValue<'a> as Deref>::Target

Dereferences the value.