diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 61a6c199701..a49b6f7e2a6 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -559,18 +559,13 @@ impl Pat {
             return false;
         }
 
-        match self.node {
-            PatKind::Ident(_, _, Some(ref p)) => p.walk(it),
-            PatKind::Struct(_, ref fields, _) => fields.iter().all(|field| field.node.pat.walk(it)),
-            PatKind::TupleStruct(_, ref s, _) | PatKind::Tuple(ref s, _) => {
+        match &self.node {
+            PatKind::Ident(_, _, Some(p)) => p.walk(it),
+            PatKind::Struct(_, fields, _) => fields.iter().all(|field| field.node.pat.walk(it)),
+            PatKind::TupleStruct(_, s) | PatKind::Tuple(s) | PatKind::Slice(s) => {
                 s.iter().all(|p| p.walk(it))
             }
-            PatKind::Box(ref s) | PatKind::Ref(ref s, _) | PatKind::Paren(ref s) => s.walk(it),
-            PatKind::Slice(ref before, ref slice, ref after) => {
-                before.iter().all(|p| p.walk(it))
-                    && slice.iter().all(|p| p.walk(it))
-                    && after.iter().all(|p| p.walk(it))
-            }
+            PatKind::Box(s) | PatKind::Ref(s, _) | PatKind::Paren(s) => s.walk(it),
             PatKind::Wild
             | PatKind::Rest
             | PatKind::Lit(_)
@@ -639,9 +634,7 @@ pub enum PatKind {
     Struct(Path, Vec<Spanned<FieldPat>>, /* recovered */ bool),
 
     /// A tuple struct/variant pattern (`Variant(x, y, .., z)`).
-    /// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
-    /// `0 <= position <= subpats.len()`.
-    TupleStruct(Path, Vec<P<Pat>>, Option<usize>),
+    TupleStruct(Path, Vec<P<Pat>>),
 
     /// A possibly qualified path pattern.
     /// Unqualified path patterns `A::B::C` can legally refer to variants, structs, constants
@@ -650,9 +643,7 @@ pub enum PatKind {
     Path(Option<QSelf>, Path),
 
     /// A tuple pattern (`(a, b)`).
-    /// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
-    /// `0 <= position <= subpats.len()`.
-    Tuple(Vec<P<Pat>>, Option<usize>),
+    Tuple(Vec<P<Pat>>),
 
     /// A `box` pattern.
     Box(P<Pat>),
@@ -666,9 +657,8 @@ pub enum PatKind {
     /// A range pattern (e.g., `1...2`, `1..=2` or `1..2`).
     Range(P<Expr>, P<Expr>, Spanned<RangeEnd>),
 
-    /// `[a, b, ..i, y, z]` is represented as:
-    ///     `PatKind::Slice(box [a, b], Some(i), box [y, z])`
-    Slice(Vec<P<Pat>>, Option<P<Pat>>, Vec<P<Pat>>),
+    /// A slice pattern `[a, b, c]`.
+    Slice(Vec<P<Pat>>),
 
     /// A rest pattern `..`.
     ///
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index baf1031de1e..528b27d6153 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -840,14 +840,14 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
     }
     fn pat_tuple_struct(&self, span: Span, path: ast::Path,
                         subpats: Vec<P<ast::Pat>>) -> P<ast::Pat> {
-        self.pat(span, PatKind::TupleStruct(path, subpats, None))
+        self.pat(span, PatKind::TupleStruct(path, subpats))
     }
     fn pat_struct(&self, span: Span, path: ast::Path,
                   field_pats: Vec<Spanned<ast::FieldPat>>) -> P<ast::Pat> {
         self.pat(span, PatKind::Struct(path, field_pats, false))
     }
     fn pat_tuple(&self, span: Span, pats: Vec<P<ast::Pat>>) -> P<ast::Pat> {
-        self.pat(span, PatKind::Tuple(pats, None))
+        self.pat(span, PatKind::Tuple(pats))
     }
 
     fn pat_some(&self, span: Span, pat: P<ast::Pat>) -> P<ast::Pat> {
diff --git a/src/libsyntax/mut_visit.rs b/src/libsyntax/mut_visit.rs
index eb25956a769..86525406718 100644
--- a/src/libsyntax/mut_visit.rs
+++ b/src/libsyntax/mut_visit.rs
@@ -1026,9 +1026,9 @@ pub fn noop_visit_pat<T: MutVisitor>(pat: &mut P<Pat>, vis: &mut T) {
             visit_opt(sub, |sub| vis.visit_pat(sub));
         }
         PatKind::Lit(e) => vis.visit_expr(e),
-        PatKind::TupleStruct(path, pats, _ddpos) => {
+        PatKind::TupleStruct(path, elems) => {
             vis.visit_path(path);
-            visit_vec(pats, |pat| vis.visit_pat(pat));
+            visit_vec(elems, |elem| vis.visit_pat(elem));
         }
         PatKind::Path(qself, path) => {
             vis.visit_qself(qself);
@@ -1043,7 +1043,7 @@ pub fn noop_visit_pat<T: MutVisitor>(pat: &mut P<Pat>, vis: &mut T) {
                 vis.visit_span(span);
             };
         }
-        PatKind::Tuple(elts, _ddpos) => visit_vec(elts, |elt| vis.visit_pat(elt)),
+        PatKind::Tuple(elems) => visit_vec(elems, |elem| vis.visit_pat(elem)),
         PatKind::Box(inner) => vis.visit_pat(inner),
         PatKind::Ref(inner, _mutbl) => vis.visit_pat(inner),
         PatKind::Range(e1, e2, Spanned { span: _, node: _ }) => {
@@ -1051,11 +1051,7 @@ pub fn noop_visit_pat<T: MutVisitor>(pat: &mut P<Pat>, vis: &mut T) {
             vis.visit_expr(e2);
             vis.visit_span(span);
         }
-        PatKind::Slice(before, slice, after) => {
-            visit_vec(before, |pat| vis.visit_pat(pat));
-            visit_opt(slice, |slice| vis.visit_pat(slice));
-            visit_vec(after, |pat| vis.visit_pat(pat));
-        }
+        PatKind::Slice(elems) => visit_vec(elems, |elem| vis.visit_pat(elem)),
         PatKind::Paren(inner) => vis.visit_pat(inner),
         PatKind::Mac(mac) => vis.visit_mac(mac),
     }
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 7c814bf3397..ff6440fb9dc 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -428,9 +428,9 @@ pub fn walk_assoc_ty_constraint<'a, V: Visitor<'a>>(visitor: &mut V,
 
 pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
     match pattern.node {
-        PatKind::TupleStruct(ref path, ref children, _) => {
+        PatKind::TupleStruct(ref path, ref elems) => {
             visitor.visit_path(path, pattern.id);
-            walk_list!(visitor, visit_pat, children);
+            walk_list!(visitor, visit_pat, elems);
         }
         PatKind::Path(ref opt_qself, ref path) => {
             if let Some(ref qself) = *opt_qself {
@@ -446,8 +446,8 @@ pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
                 visitor.visit_pat(&field.node.pat)
             }
         }
-        PatKind::Tuple(ref tuple_elements, _) => {
-            walk_list!(visitor, visit_pat, tuple_elements);
+        PatKind::Tuple(ref elems) => {
+            walk_list!(visitor, visit_pat, elems);
         }
         PatKind::Box(ref subpattern) |
         PatKind::Ref(ref subpattern, _) |
@@ -464,10 +464,8 @@ pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
             visitor.visit_expr(upper_bound);
         }
         PatKind::Wild | PatKind::Rest => {},
-        PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
-            walk_list!(visitor, visit_pat, prepatterns);
-            walk_list!(visitor, visit_pat, slice_pattern);
-            walk_list!(visitor, visit_pat, postpatterns);
+        PatKind::Slice(ref elems) => {
+            walk_list!(visitor, visit_pat, elems);
         }
         PatKind::Mac(ref mac) => visitor.visit_mac(mac),
     }