Removed need for Downcast on Function

Author: MrGVSV

crates/bevy_reflect/src/func/dynamic_function.rs

@@ -154,6 +154,10 @@ impl Function for DynamicFunction<'static> {
     fn reflect_call<'a>(&self, args: ArgList<'a>) -> FunctionResult<'a> {
         self.call(args)
     }
+
+    fn clone_dynamic(&self) -> DynamicFunction<'static> {
+        self.clone()
+    }
 }
 
 impl PartialReflect for DynamicFunction<'static> {
@@ -186,16 +190,16 @@ impl PartialReflect for DynamicFunction<'static> {
     }
 
     fn try_apply(&mut self, value: &dyn PartialReflect) -> Result<(), ApplyError> {
-        if let ReflectRef::Function(func) = value.reflect_ref() {
-            if let Some(func) = func.downcast_ref::<Self>() {
-                *self = func.clone();
-                return Ok(());
+        match value.reflect_ref() {
+            ReflectRef::Function(func) => {
+                *self = func.clone_dynamic();
+                Ok(())
             }
+            _ => Err(ApplyError::MismatchedTypes {
+                from_type: value.reflect_type_path().into(),
+                to_type: Self::type_path().into(),
+            }),
         }
-        Err(ApplyError::MismatchedTypes {
-            from_type: value.reflect_type_path().into(),
-            to_type: Self::type_path().into(),
-        })
     }
 
     fn reflect_kind(&self) -> ReflectKind {

crates/bevy_reflect/src/func/function.rs

@@ -1,8 +1,7 @@
-use crate::func::{ArgList, FunctionInfo, FunctionResult};
+use crate::func::{ArgList, DynamicFunction, FunctionInfo, FunctionResult};
 use crate::PartialReflect;
 use alloc::borrow::Cow;
 use core::fmt::Debug;
-use downcast_rs::{impl_downcast, Downcast};
 
 /// A trait used to power [function-like] operations via [reflection].
 ///
@@ -31,7 +30,7 @@ use downcast_rs::{impl_downcast, Downcast};
 /// [`Reflect`]: crate::Reflect
 /// [arguments]: crate::func::args
 /// [`DynamicFunction`]: crate::func::DynamicFunction
-pub trait Function: PartialReflect + Downcast + Debug {
+pub trait Function: PartialReflect + Debug {
     /// The name of the function, if any.
     ///
     /// For [`DynamicFunctions`] created using [`IntoFunction`],
@@ -55,11 +54,10 @@ pub trait Function: PartialReflect + Downcast + Debug {
 
     /// Call this function with the given arguments.
     fn reflect_call<'a>(&self, args: ArgList<'a>) -> FunctionResult<'a>;
-}
 
-// We need to be able to downcast from `dyn Function` so that
-// we can implement `PartialReflect::try_apply`.
-impl_downcast!(Function);
+    /// Clone this function into a [`DynamicFunction`].
+    fn clone_dynamic(&self) -> DynamicFunction<'static>;
+}
 
 #[cfg(test)]
 mod tests {