From c4bbe9cbbe9921646cdedb856e34dc951641ed96 Mon Sep 17 00:00:00 2001
From: Mazdak Farrokhzad <twingoow@gmail.com>
Date: Sat, 30 Nov 2019 18:25:44 +0100
Subject: Alias `TraitItem` & `ImplItem`. Allow defaultness on trait items
 syntactically.

---
 src/libsyntax/ast.rs          | 22 +++++-----------------
 src/libsyntax/mut_visit.rs    |  3 ++-
 src/libsyntax/print/pprust.rs |  1 +
 3 files changed, 8 insertions(+), 18 deletions(-)

(limited to 'src/libsyntax')

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 92ba071a03d..964acfa92b9 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1603,24 +1603,12 @@ pub struct FnSig {
     pub decl: P<FnDecl>,
 }
 
-/// Represents an item declaration within a trait declaration,
+pub type TraitItem = ImplItem<TraitItemKind>;
+
+/// Represents the kind of an item declaration within a trait declaration,
 /// possibly including a default implementation. A trait item is
 /// either required (meaning it doesn't have an implementation, just a
 /// signature) or provided (meaning it has a default implementation).
-#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
-pub struct TraitItem {
-    pub attrs: Vec<Attribute>,
-    pub id: NodeId,
-    pub span: Span,
-    pub vis: Visibility,
-    pub ident: Ident,
-
-    pub generics: Generics,
-    pub kind: TraitItemKind,
-    /// See `Item::tokens` for what this is.
-    pub tokens: Option<TokenStream>,
-}
-
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
 pub enum TraitItemKind {
     Const(P<Ty>, Option<P<Expr>>),
@@ -1631,7 +1619,7 @@ pub enum TraitItemKind {
 
 /// Represents anything within an `impl` block.
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
-pub struct ImplItem {
+pub struct ImplItem<K = ImplItemKind> {
     pub attrs: Vec<Attribute>,
     pub id: NodeId,
     pub span: Span,
@@ -1640,7 +1628,7 @@ pub struct ImplItem {
 
     pub defaultness: Defaultness,
     pub generics: Generics,
-    pub kind: ImplItemKind,
+    pub kind: K,
     /// See `Item::tokens` for what this is.
     pub tokens: Option<TokenStream>,
 }
diff --git a/src/libsyntax/mut_visit.rs b/src/libsyntax/mut_visit.rs
index f8795d885d2..9d0a29f2951 100644
--- a/src/libsyntax/mut_visit.rs
+++ b/src/libsyntax/mut_visit.rs
@@ -939,7 +939,8 @@ pub fn noop_visit_item_kind<T: MutVisitor>(kind: &mut ItemKind, vis: &mut T) {
 pub fn noop_flat_map_trait_item<T: MutVisitor>(mut item: TraitItem, visitor: &mut T)
     -> SmallVec<[TraitItem; 1]>
 {
-    let TraitItem { id, ident, vis, attrs, generics, kind, span, tokens: _ } = &mut item;
+    let TraitItem { id, ident, vis, defaultness: _, attrs, generics, kind, span, tokens: _ } =
+        &mut item;
     visitor.visit_id(id);
     visitor.visit_ident(ident);
     visitor.visit_vis(vis);
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index f0c5fb32fb1..2e3ea5e2444 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1550,6 +1550,7 @@ impl<'a> State<'a> {
         self.hardbreak_if_not_bol();
         self.maybe_print_comment(ti.span.lo());
         self.print_outer_attributes(&ti.attrs);
+        self.print_defaultness(ti.defaultness);
         match ti.kind {
             ast::TraitItemKind::Const(ref ty, ref default) => {
                 self.print_associated_const(
-- 
cgit 1.4.1-3-g733a5