From c738e6042d2925bbfb045982fabe1f902f8b7c72 Mon Sep 17 00:00:00 2001
From: purple-ice <jaidy379@gmail.com>
Date: Thu, 3 Jan 2019 20:15:01 +0200
Subject: [PATCH 1/2] Extend E0106, E0261

Added an example that points out hardly obvious mistake one could make when writing impl for a new type.
---
 src/librustc/diagnostics.rs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs
index 4bc52e82f9be1..50beacf3e8cbb 100644
--- a/src/librustc/diagnostics.rs
+++ b/src/librustc/diagnostics.rs
@@ -362,6 +362,10 @@ struct Foo1 { x: &bool }
               // ^ expected lifetime parameter
 struct Foo2<'a> { x: &'a bool } // correct
 
+impl Foo2 { ... }
+  // ^ expected lifetime parameter
+impl<'a> Foo2<'a> { ... } // correct
+
 struct Bar1 { x: Foo2 }
               // ^^^^ expected lifetime parameter
 struct Bar2<'a> { x: Foo2<'a> } // correct
@@ -772,6 +776,24 @@ struct Foo<'a> {
     x: &'a str,
 }
 ```
+
+Implementations need their own lifetime declarations:
+    
+```
+// error, undeclared lifetime
+impl Foo<'a> {
+    ...
+}
+```
+
+Which are declared like this:
+
+```
+// correct
+impl<'a> Foo<'a> {
+    ...
+}
+```
 "##,
 
 E0262: r##"

From adadefd8741d84ebfb5884fbd12f3202cd6fdb4f Mon Sep 17 00:00:00 2001
From: purple-ice <jaidy379@gmail.com>
Date: Fri, 4 Jan 2019 13:00:26 +0200
Subject: [PATCH 2/2] Fix changes for E0106, E0261

Replaced impl block dock with suggested one and made sure that blocks compile.
---
 src/librustc/diagnostics.rs | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs
index 50beacf3e8cbb..dd5144b1568fb 100644
--- a/src/librustc/diagnostics.rs
+++ b/src/librustc/diagnostics.rs
@@ -362,9 +362,9 @@ struct Foo1 { x: &bool }
               // ^ expected lifetime parameter
 struct Foo2<'a> { x: &'a bool } // correct
 
-impl Foo2 { ... }
+impl Foo2 {}
   // ^ expected lifetime parameter
-impl<'a> Foo2<'a> { ... } // correct
+impl<'a> Foo2<'a> {} // correct
 
 struct Bar1 { x: Foo2 }
               // ^^^^ expected lifetime parameter
@@ -777,21 +777,32 @@ struct Foo<'a> {
 }
 ```
 
-Implementations need their own lifetime declarations:
+Impl blocks declare lifetime parameters separately. You need to add lifetime
+parameters to an impl block if you're implementing a type that has a lifetime
+parameter of its own.
+For example:
     
-```
-// error, undeclared lifetime
+```compile_fail,E0261
+// error,  use of undeclared lifetime name `'a`
 impl Foo<'a> {
-    ...
+    fn foo<'a>(x: &'a str) {}
+}
+    
+struct Foo<'a> {
+    x: &'a str,
 }
 ```
 
-Which are declared like this:
+This is fixed by declaring impl block like this:
 
 ```
 // correct
 impl<'a> Foo<'a> {
-    ...
+    fn foo(x: &'a str) {}
+}
+    
+struct Foo<'a> {
+    x: &'a str,
 }
 ```
 "##,