Optimize FromReflect impl

First attempt to downcast, then call `from_reflect`
EmbarkStudios · Dec 5, 2022 · a30ad56 · a30ad56
1 parent 151d900
commit a30ad56
Show file tree

Hide file tree

Showing 3 changed files with 32 additions and 6 deletions.
diff --git a/crates/mirror-mirror-macros/src/derive_reflect/enum_.rs b/crates/mirror-mirror-macros/src/derive_reflect/enum_.rs
@@ -302,7 +302,14 @@ fn expand_from_reflect(ident: &Ident, variants: &[VariantData<'_>]) -> TokenStre
                         let ident_string = stringify(ident);
                         let ty = &field.ty;
                         quote! {
-                            #ident: <#ty as FromReflect>::from_reflect(enum_.field(#ident_string)?)?.to_owned(),
+                            #ident: {
+                                let value = enum_.field(#ident_string)?;
+                                if let Some(value) = value.downcast_ref::<#ty>() {
+                                    value.to_owned()
+                                } else {
+                                    <#ty as FromReflect>::from_reflect(value)?.to_owned()
+                                }
+                            },
                         }
                     }
                 });
@@ -322,7 +329,14 @@ fn expand_from_reflect(ident: &Ident, variants: &[VariantData<'_>]) -> TokenStre
                     } else {
                         let ty = &field.ty;
                         quote! {
-                            <#ty as FromReflect>::from_reflect(enum_.field_at(#idx)?)?.to_owned(),
+                            {
+                                let value = enum_.field_at(#idx)?;
+                                if let Some(value) = value.downcast_ref::<#ty>() {
+                                    value.to_owned()
+                                } else {
+                                    <#ty as FromReflect>::from_reflect(value)?.to_owned()
+                                }
+                            },
                         }
                     }
                 });

diff --git a/crates/mirror-mirror-macros/src/derive_reflect/struct_named.rs b/crates/mirror-mirror-macros/src/derive_reflect/struct_named.rs
@@ -173,7 +173,14 @@ fn expand_from_reflect(
                 let ty = &field.ty;
                 let field = stringify(ident);
                 quote_spanned! {span=>
-                    #ident: <#ty as FromReflect>::from_reflect(struct_.field(#field)?)?.to_owned(),
+                    #ident: {
+                        let value = struct_.field(#field)?;
+                        if let Some(value) = value.downcast_ref::<#ty>() {
+                            value.to_owned()
+                        } else {
+                            <#ty as FromReflect>::from_reflect(value)?.to_owned()
+                        }
+                    },
                 }
             }
         });

diff --git a/crates/mirror-mirror-macros/src/derive_reflect/tuple_struct.rs b/crates/mirror-mirror-macros/src/derive_reflect/tuple_struct.rs
@@ -175,9 +175,14 @@ fn expand_from_reflect(
                 }
             } else {
                 quote_spanned! {span=>
-                    #field_index: <#ty as FromReflect>::from_reflect(
-                        tuple_struct.field(#field_index)?,
-                    )?.to_owned(),
+                    #field_index: {
+                        let value = tuple_struct.field(#field_index)?;
+                        if let Some(value) = value.downcast_ref::<#ty>() {
+                            value.to_owned()
+                        } else {
+                            <#ty as FromReflect>::from_reflect(value)?.to_owned()
+                        }
+                    },
                 }
             }
         });