From e52a48851054f7cab4a5f646f39ddc001032dd78 Mon Sep 17 00:00:00 2001
From: Seiichi Uchida <seuchida@gmail.com>
Date: Mon, 7 Sep 2020 18:27:40 +0900
Subject: [PATCH 1/2] Add a test for #4357

---
 tests/source/type.rs | 6 ++++++
 tests/target/type.rs | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/tests/source/type.rs b/tests/source/type.rs
index eb4600e5bce..57f31dc901e 100644
--- a/tests/source/type.rs
+++ b/tests/source/type.rs
@@ -166,3 +166,9 @@ impl<T:   ?  const Trait> Foo<T> {
         Self(t)
     }
 }
+
+// #4357
+type T = typeof(
+1);
+impl T for  .. {
+}
\ No newline at end of file
diff --git a/tests/target/type.rs b/tests/target/type.rs
index 20e97440e7c..e7761251688 100644
--- a/tests/target/type.rs
+++ b/tests/target/type.rs
@@ -177,3 +177,7 @@ impl<T: ?const Trait> Foo<T> {
         Self(t)
     }
 }
+
+// #4357
+type T = typeof(1);
+impl T for .. {}

From 526b1b87860055bc62b8ea958b9fb2ee1659d58f Mon Sep 17 00:00:00 2001
From: Seiichi Uchida <seuchida@gmail.com>
Date: Mon, 7 Sep 2020 18:27:51 +0900
Subject: [PATCH 2/2] Format error and typeof types

---
 src/formatting/types.rs | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/formatting/types.rs b/src/formatting/types.rs
index be5745bd815..b4ead894f2f 100644
--- a/src/formatting/types.rs
+++ b/src/formatting/types.rs
@@ -6,7 +6,10 @@ use rustc_span::{symbol::kw, BytePos, Span};
 
 use crate::config::{lists::*, IndentStyle, TypeDensity};
 use crate::formatting::{
-    expr::{format_expr, rewrite_assign_rhs, rewrite_tuple, rewrite_unary_prefix, ExprType},
+    expr::{
+        format_expr, rewrite_assign_rhs, rewrite_call, rewrite_tuple, rewrite_unary_prefix,
+        ExprType,
+    },
     lists::{definitive_tactic, itemize_list, write_list, ListFormatting, ListItem, Separator},
     macros::{rewrite_macro, MacroPosition},
     overflow,
@@ -756,7 +759,14 @@ impl Rewrite for ast::Ty {
                 })
             }
             ast::TyKind::CVarArgs => Some("...".to_owned()),
-            ast::TyKind::Err | ast::TyKind::Typeof(..) => unreachable!(),
+            ast::TyKind::Err => Some(context.snippet(self.span).to_owned()),
+            ast::TyKind::Typeof(ref anon_const) => rewrite_call(
+                context,
+                "typeof",
+                &[anon_const.value.clone()],
+                self.span,
+                shape,
+            ),
         }
     }
 }