Convert process_variant functions into closures.

nnethercote · nnethercote · commit 02d2cdfc288c · 2022-06-27T08:14:09.000+10:00
It makes things a bit nicer.
diff --git a/compiler/rustc_builtin_macros/src/deriving/clone.rs b/compiler/rustc_builtin_macros/src/deriving/clone.rs
@@ -107,20 +107,20 @@ fn cs_clone_shallow(
     substr: &Substructure<'_>,
     is_union: bool,
 ) -> P<Expr> {
-    fn process_variant(cx: &mut ExtCtxt<'_>, stmts: &mut Vec<ast::Stmt>, variant: &VariantData) {
+    let mut stmts = Vec::new();
+    let mut process_variant = |variant: &VariantData| {
         for field in variant.fields() {
             // let _: AssertParamIsClone<FieldTy>;
             super::assert_ty_bounds(
                 cx,
-                stmts,
+                &mut stmts,
                 field.ty.clone(),
                 field.span,
                 &[sym::clone, sym::AssertParamIsClone],
             );
         }
-    }
+    };
 
-    let mut stmts = Vec::new();
     if is_union {
         // let _: AssertParamIsCopy<Self>;
         let self_ty = cx.ty_path(cx.path_ident(trait_span, Ident::with_dummy_span(kw::SelfUpper)));
@@ -134,11 +134,11 @@ fn cs_clone_shallow(
     } else {
         match *substr.fields {
             StaticStruct(vdata, ..) => {
-                process_variant(cx, &mut stmts, vdata);
+                process_variant(vdata);
             }
             StaticEnum(enum_def, ..) => {
                 for variant in &enum_def.variants {
-                    process_variant(cx, &mut stmts, &variant.data);
+                    process_variant(&variant.data);
                 }
             }
             _ => cx.span_bug(
diff --git a/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs b/compiler/rustc_builtin_macros/src/deriving/cmp/eq.rs
@@ -55,31 +55,27 @@ fn cs_total_eq_assert(
     trait_span: Span,
     substr: &Substructure<'_>,
 ) -> P<Expr> {
-    fn process_variant(
-        cx: &mut ExtCtxt<'_>,
-        stmts: &mut Vec<ast::Stmt>,
-        variant: &ast::VariantData,
-    ) {
+    let mut stmts = Vec::new();
+    let mut process_variant = |variant: &ast::VariantData| {
         for field in variant.fields() {
             // let _: AssertParamIsEq<FieldTy>;
             super::assert_ty_bounds(
                 cx,
-                stmts,
+                &mut stmts,
                 field.ty.clone(),
                 field.span,
                 &[sym::cmp, sym::AssertParamIsEq],
             );
         }
-    }
+    };
 
-    let mut stmts = Vec::new();
     match *substr.fields {
         StaticStruct(vdata, ..) => {
-            process_variant(cx, &mut stmts, vdata);
+            process_variant(vdata);
         }
         StaticEnum(enum_def, ..) => {
             for variant in &enum_def.variants {
-                process_variant(cx, &mut stmts, &variant.data);
+                process_variant(&variant.data);
             }
         }
         _ => cx.span_bug(trait_span, "unexpected substructure in `derive(Eq)`"),
