diff --git a/src/libsyntax/diagnostics/plugin.rs b/src/libsyntax/diagnostics/plugin.rs
index b4cf24f5ac519..98351048c3526 100644
--- a/src/libsyntax/diagnostics/plugin.rs
+++ b/src/libsyntax/diagnostics/plugin.rs
@@ -34,7 +34,7 @@ pub fn expand_diagnostic_used<'cx>(ecx: &'cx mut ExtCtxt<'_>,
                                    token_tree: &[TokenTree])
                                    -> Box<dyn MacResult+'cx> {
     let code = match token_tree {
-        &[
+        [
             TokenTree::Token(Token { kind: token::Ident(code, _), .. })
         ] => code,
         _ => unreachable!()
@@ -69,17 +69,17 @@ pub fn expand_register_diagnostic<'cx>(ecx: &'cx mut ExtCtxt<'_>,
                                        token_tree: &[TokenTree])
                                        -> Box<dyn MacResult+'cx> {
     let (code, description) = match  token_tree {
-        &[
+        [
             TokenTree::Token(Token { kind: token::Ident(code, _), .. })
         ] => {
-            (code, None)
+            (*code, None)
         },
-        &[
+        [
             TokenTree::Token(Token { kind: token::Ident(code, _), .. }),
             TokenTree::Token(Token { kind: token::Comma, .. }),
             TokenTree::Token(Token { kind: token::Literal(token::Lit { symbol, .. }), ..})
         ] => {
-            (code, Some(symbol))
+            (*code, Some(*symbol))
         },
         _ => unreachable!()
     };
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 025972d8ca78b..b912bf8295ae1 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -434,15 +434,15 @@ mod tests {
                 if name_macro_rules == sym::macro_rules && name_zip.as_str() == "zip" => {
                     let tts = &macro_tts.trees().collect::<Vec<_>>();
                     match tts {
-                        &[
-                            TokenTree::Delimited(_, first_delim, ref first_tts),
+                        [
+                            TokenTree::Delimited(_, first_delim, first_tts),
                             TokenTree::Token(Token { kind: token::FatArrow, .. }),
-                            TokenTree::Delimited(_, second_delim, ref second_tts),
+                            TokenTree::Delimited(_, second_delim, second_tts),
                         ]
                         if macro_delim == token::Paren => {
                             let tts = &first_tts.trees().collect::<Vec<_>>();
                             match tts {
-                                &[
+                                [
                                     TokenTree::Token(Token { kind: token::Dollar, .. }),
                                     TokenTree::Token(Token { kind: token::Ident(name, false), .. }),
                                 ]
@@ -451,7 +451,7 @@ mod tests {
                             }
                             let tts = &second_tts.trees().collect::<Vec<_>>();
                             match tts {
-                                &[
+                                [
                                     TokenTree::Token(Token { kind: token::Dollar, .. }),
                                     TokenTree::Token(Token { kind: token::Ident(name, false), .. }),
                                 ]