Add upcasting to the Reflect trait

Author: Davier

crates/bevy_reflect/bevy_reflect_derive/src/lib.rs

@@ -318,6 +318,14 @@ fn impl_struct(
             fn reflect_partial_eq(&self, value: &dyn #bevy_reflect_path::Reflect) -> Option<bool> {
                 #partial_eq_fn
             }
+
+            fn as_reflect(&self) -> &dyn #bevy_reflect_path::Reflect {
+                self
+            }
+
+            fn as_reflect_mut(&mut self) -> &mut dyn #bevy_reflect_path::Reflect {
+                self
+            }
         }
     })
 }
@@ -437,6 +445,14 @@ fn impl_tuple_struct(
             fn reflect_partial_eq(&self, value: &dyn #bevy_reflect_path::Reflect) -> Option<bool> {
                 #partial_eq_fn
             }
+
+            fn as_reflect(&self) -> &dyn #bevy_reflect_path::Reflect {
+                self
+            }
+
+            fn as_reflect_mut(&mut self) -> &mut dyn #bevy_reflect_path::Reflect {
+                self
+            }
         }
     })
 }
@@ -512,6 +528,14 @@ fn impl_value(
             fn serializable(&self) -> Option<#bevy_reflect_path::serde::Serializable> {
                 #serialize_fn
             }
+
+            fn as_reflect(&self) -> &dyn #bevy_reflect_path::Reflect {
+                self
+            }
+
+            fn as_reflect_mut(&mut self) -> &mut dyn #bevy_reflect_path::Reflect {
+                self
+            }
         }
     })
 }

crates/bevy_reflect/src/impls/smallvec.rs

@@ -93,4 +93,12 @@ where
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }

crates/bevy_reflect/src/impls/std.rs

@@ -104,6 +104,14 @@ impl<T: Reflect> Reflect for Vec<T> {
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }
 
 impl<K: Reflect + Clone + Eq + Hash, V: Reflect + Clone> Map for HashMap<K, V> {
@@ -198,4 +206,12 @@ impl<K: Reflect + Clone + Eq + Hash, V: Reflect + Clone> Reflect for HashMap<K,
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }

crates/bevy_reflect/src/list.rs

@@ -122,6 +122,14 @@ impl Reflect for DynamicList {
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }
 
 pub struct ListIter<'a> {

crates/bevy_reflect/src/map.rs

@@ -141,6 +141,14 @@ impl Reflect for DynamicMap {
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }
 
 pub struct MapIter<'a> {

crates/bevy_reflect/src/reflect.rs

@@ -39,6 +39,8 @@ pub trait Reflect: Any + Send + Sync {
     fn reflect_partial_eq(&self, _value: &dyn Reflect) -> Option<bool>;
     /// Returns a serializable value, if serialization is supported. Otherwise `None` will be returned.
     fn serializable(&self) -> Option<Serializable>;
+    fn as_reflect(&self) -> &dyn Reflect;
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect;
 }
 
 impl Debug for dyn Reflect {

crates/bevy_reflect/src/struct_trait.rs

@@ -227,6 +227,14 @@ impl Reflect for DynamicStruct {
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }
 
 #[inline]

crates/bevy_reflect/src/tuple.rs

@@ -165,6 +165,14 @@ impl Reflect for DynamicTuple {
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }
 
 #[inline]
@@ -291,6 +299,14 @@ macro_rules! impl_reflect_tuple {
             fn serializable(&self) -> Option<Serializable> {
                 None
             }
+
+            fn as_reflect(&self) -> &dyn Reflect {
+                self
+            }
+        
+            fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+                self
+            }
         }
     }
 }

crates/bevy_reflect/src/tuple_struct.rs

@@ -182,6 +182,14 @@ impl Reflect for DynamicTupleStruct {
     fn serializable(&self) -> Option<Serializable> {
         None
     }
+
+    fn as_reflect(&self) -> &dyn Reflect {
+        self
+    }
+
+    fn as_reflect_mut(&mut self) -> &mut dyn Reflect {
+        self
+    }
 }
 
 #[inline]