fix single-use lint

src/test/ui/in-band-lifetimes/single_use_lifetimes-2.stderr

@@ -1,14 +0,0 @@
-error: lifetime name `'x` only used once
-  --> $DIR/single_use_lifetimes-2.rs:12:10
-   |
-LL | fn deref<'x>() -> &'x u32 { //~ ERROR lifetime name `'x` only used once
-   |          ^^
-   |
-note: lint level defined here
-  --> $DIR/single_use_lifetimes-2.rs:10:9
-   |
-LL | #![deny(single_use_lifetime)]
-   |         ^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to previous error
-

src/test/ui/in-band-lifetimes/single_use_lifetimes-3.stderr

@@ -1,20 +0,0 @@
-error: lifetime name `'x` only used once
-  --> $DIR/single_use_lifetimes-3.rs:11:12
-   |
-LL | struct Foo<'x> { //~ ERROR lifetime name `'x` only used once
-   |            ^^
-   |
-note: lint level defined here
-  --> $DIR/single_use_lifetimes-3.rs:10:9
-   |
-LL | #![deny(single_use_lifetime)]
-   |         ^^^^^^^^^^^^^^^^^^^
-
-error: lifetime name `'y` only used once
-  --> $DIR/single_use_lifetimes-3.rs:16:6
-   |
-LL | impl<'y> Foo<'y> { //~ ERROR lifetime name `'y` only used once
-   |      ^^
-
-error: aborting due to 2 previous errors
-

src/test/ui/in-band-lifetimes/single_use_lifetimes-4.stderr

@@ -1,20 +0,0 @@
-error: lifetime name `'x` only used once
-  --> $DIR/single_use_lifetimes-4.rs:12:12
-   |
-LL | struct Foo<'x> { //~ ERROR lifetime name `'x` only used once
-   |            ^^
-   |
-note: lint level defined here
-  --> $DIR/single_use_lifetimes-4.rs:10:9
-   |
-LL | #![deny(single_use_lifetime)]
-   |         ^^^^^^^^^^^^^^^^^^^
-
-error: lifetime name `'x` only used once
-  --> $DIR/single_use_lifetimes-4.rs:16:10
-   |
-LL | enum Bar<'x> { //~ ERROR lifetime name `'x` only used once
-   |          ^^
-
-error: aborting due to 2 previous errors
-

src/test/ui/in-band-lifetimes/single_use_lifetimes-5.stderr

@@ -1,14 +0,0 @@
-error: lifetime name `'x` only used once
-  --> $DIR/single_use_lifetimes-5.rs:12:11
-   |
-LL | trait Foo<'x> { //~ ERROR lifetime name `'x` only used once
-   |           ^^
-   |
-note: lint level defined here
-  --> $DIR/single_use_lifetimes-5.rs:10:9
-   |
-LL | #![deny(single_use_lifetime)]
-   |         ^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to previous error
-

src/test/ui/in-band-lifetimes/single_use_lifetimes.rs

@@ -1,16 +0,0 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-#![deny(single_use_lifetime)]
-
-fn deref<'x>(v: &'x u32) -> u32 { //~ ERROR lifetime name `'x` only used once
-    *v
-}
-
-fn main() {}

src/test/ui/in-band-lifetimes/single_use_lifetimes.stderr

@@ -1,14 +0,0 @@
-error: lifetime name `'x` only used once
-  --> $DIR/single_use_lifetimes.rs:12:10
-   |
-LL | fn deref<'x>(v: &'x u32) -> u32 { //~ ERROR lifetime name `'x` only used once
-   |          ^^
-   |
-note: lint level defined here
-  --> $DIR/single_use_lifetimes.rs:10:9
-   |
-LL | #![deny(single_use_lifetime)]
-   |         ^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to previous error
-

src/test/ui/single-use-lifetime/fn-types.rs

@@ -0,0 +1,26 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO warn when lifetime name is used only
+// once in a fn argument.
+
+struct Foo {
+  a: for<'a> fn(&'a u32), //~ ERROR `'a` only used once
+  b: for<'a> fn(&'a u32, &'a u32), // OK, used twice.
+  c: for<'a> fn(&'a u32) -> &'a u32, // OK, used twice.
+  d: for<'a> fn() -> &'a u32, // OK, used only in return type.
+    //~^ ERROR return type references lifetime `'a`, which is not constrained by the fn input types
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/fn-types.stderr

@@ -0,0 +1,21 @@
+error: lifetime parameter `'a` only used once
+  --> $DIR/fn-types.rs:19:10
+   |
+LL |   a: for<'a> fn(&'a u32), //~ ERROR `'a` only used once
+   |          ^^
+   |
+note: lint level defined here
+  --> $DIR/fn-types.rs:11:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error[E0581]: return type references lifetime `'a`, which is not constrained by the fn input types
+  --> $DIR/fn-types.rs:22:22
+   |
+LL |   d: for<'a> fn() -> &'a u32, // OK, used only in return type.
+   |                      ^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0581`.

src/test/ui/single-use-lifetime/one-use-in-fn-argument-in-band.rs

@@ -0,0 +1,24 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(in_band_lifetimes)]
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO warn when lifetime name is used only
+// once in a fn argument, even with in band lifetimes.
+
+fn a(x: &'a u32, y: &'b u32) {
+    //~^ ERROR `'a` only used once
+    //~| ERROR `'b` only used once
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-fn-argument-in-band.stderr

@@ -0,0 +1,20 @@
+error: lifetime parameter `'b` only used once
+  --> $DIR/one-use-in-fn-argument-in-band.rs:19:22
+   |
+LL | fn a(x: &'a u32, y: &'b u32) {
+   |                      ^^
+   |
+note: lint level defined here
+  --> $DIR/one-use-in-fn-argument-in-band.rs:12:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: lifetime parameter `'a` only used once
+  --> $DIR/one-use-in-fn-argument-in-band.rs:19:10
+   |
+LL | fn a(x: &'a u32, y: &'b u32) {
+   |          ^^
+
+error: aborting due to 2 previous errors
+

src/test/ui/single-use-lifetime/one-use-in-fn-argument.rs

@@ -1,4 +1,4 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -7,10 +7,15 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
+
 #![deny(single_use_lifetime)]
-// FIXME(#44752) -- this scenario should not be warned
-fn deref<'x>() -> &'x u32 { //~ ERROR lifetime name `'x` only used once
-    22
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO warn when lifetime name is used only
+// once in a fn argument.
+
+fn a<'a>(x: &'a u32) { //~ ERROR `'a` only used once
 }
 
 fn main() { }

src/test/ui/single-use-lifetime/one-use-in-fn-argument.stderr

@@ -0,0 +1,14 @@
+error: lifetime parameter `'a` only used once
+  --> $DIR/one-use-in-fn-argument.rs:18:6
+   |
+LL | fn a<'a>(x: &'a u32) { //~ ERROR `'a` only used once
+   |      ^^
+   |
+note: lint level defined here
+  --> $DIR/one-use-in-fn-argument.rs:11:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/single-use-lifetime/one-use-in-fn-return.rs

@@ -0,0 +1,30 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO NOT warn when lifetime name is used only
+// once in a fn return type -- using `'_` is not legal there,
+// as it must refer back to an argument.
+//
+// (Normally, using `'static` would be preferred, but there are
+// times when that is not what you want.)
+//
+// run-pass
+
+fn b<'a>() -> &'a u32 { // OK: used only in return type
+    &22
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-inherent-impl-header.rs

@@ -0,0 +1,29 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO warn for a lifetime used only once in an impl.
+//
+// (Actually, until #15872 is fixed, you can't use `'_` here, but
+// hopefully that will come soon.)
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+    fn inherent_a(&self) {
+    }
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-inherent-impl-header.stderr

@@ -0,0 +1,14 @@
+error: lifetime parameter `'f` only used once
+  --> $DIR/one-use-in-inherent-impl-header.rs:24:6
+   |
+LL | impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+   |      ^^
+   |
+note: lint level defined here
+  --> $DIR/one-use-in-inherent-impl-header.rs:11:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/single-use-lifetime/one-use-in-inherent-method-argument.rs

@@ -0,0 +1,26 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO warn for a lifetime used only once in an inherent method.
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+    fn inherent_a<'a>(&self, data: &'a u32) { //~ ERROR `'a` only used once
+    }
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-inherent-method-argument.stderr

@@ -0,0 +1,20 @@
+error: lifetime parameter `'a` only used once
+  --> $DIR/one-use-in-inherent-method-argument.rs:22:19
+   |
+LL |     fn inherent_a<'a>(&self, data: &'a u32) { //~ ERROR `'a` only used once
+   |                   ^^
+   |
+note: lint level defined here
+  --> $DIR/one-use-in-inherent-method-argument.rs:11:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: lifetime parameter `'f` only used once
+  --> $DIR/one-use-in-inherent-method-argument.rs:21:6
+   |
+LL | impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+   |      ^^
+
+error: aborting due to 2 previous errors
+

src/test/ui/single-use-lifetime/one-use-in-inherent-method-return.rs

@@ -0,0 +1,28 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+// Test that we DO NOT warn for a lifetime used just once in a return type,
+// where that return type is in an inherent method.
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+    fn inherent_a<'a>(&self) -> &'a u32 { // OK for 'a
+        &22
+    }
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-inherent-method-return.stderr

@@ -0,0 +1,14 @@
+error: lifetime parameter `'f` only used once
+  --> $DIR/one-use-in-inherent-method-return.rs:22:6
+   |
+LL | impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+   |      ^^
+   |
+note: lint level defined here
+  --> $DIR/one-use-in-inherent-method-return.rs:11:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/single-use-lifetime/one-use-in-struct.rs

@@ -0,0 +1,31 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that we do not warn for named lifetimes in structs,
+// even when they are only used once (since to not use a named
+// lifetime is illegal!)
+//
+// compile-pass
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+enum Bar<'f> {
+    Data(&'f u32)
+}
+
+trait Baz<'f> { }
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-trait-method-argument.rs

@@ -0,0 +1,30 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that we DO warn for a lifetime on an impl used only in `&self`
+// in a trait method.
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+impl<'f> Iterator for Foo<'f> {
+    type Item = &'f u32;
+
+    fn next<'g>(&'g mut self) -> Option<Self::Item> { //~ ERROR `'g` only used once
+        None
+    }
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/one-use-in-trait-method-argument.stderr

@@ -0,0 +1,14 @@
+error: lifetime parameter `'g` only used once
+  --> $DIR/one-use-in-trait-method-argument.rs:25:13
+   |
+LL |     fn next<'g>(&'g mut self) -> Option<Self::Item> { //~ ERROR `'g` only used once
+   |             ^^
+   |
+note: lint level defined here
+  --> $DIR/one-use-in-trait-method-argument.rs:14:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/single-use-lifetime/two-uses-in-fn-argument-and-return.rs

@@ -1,4 +1,4 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -7,10 +7,18 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
+
+// Test that we DO NOT warn when lifetime name is used in
+// both the argument and return.
+//
+// compile-pass
+
 #![deny(single_use_lifetime)]
-// Should not issue a warning, as explicit lifetimes are mandatory in this case:
-trait Foo<'x> { //~ ERROR lifetime name `'x` only used once
-    fn foo(&self, arg: &'x u32);
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+fn c<'a>(x: &'a u32) -> &'a u32 { // OK: used twice
+    &22
 }
 
 fn main() { }

src/test/ui/single-use-lifetime/two-uses-in-fn-arguments.rs

@@ -1,4 +1,4 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -7,14 +7,20 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
+
+// Test that we DO NOT warn when lifetime name is used multiple
+// argments, or more than once in a single argument.
+//
+// compile-pass
+
 #![deny(single_use_lifetime)]
- // Neither should issue a warning, as explicit lifetimes are mandatory in this case
-struct Foo<'x> { //~ ERROR lifetime name `'x` only used once
-    x: &'x u32
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+fn c<'a>(x: &'a u32, y: &'a u32) { // OK: used twice
 }
 
-enum Bar<'x> { //~ ERROR lifetime name `'x` only used once
-    Variant(&'x u32)
+fn d<'a>(x: (&'a u32, &'a u32)) { // OK: used twice
 }
 
 fn main() { }

src/test/ui/single-use-lifetime/two-uses-in-inherent-impl-header.rs

@@ -1,4 +1,4 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -7,14 +7,22 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
+
+// Test that we DO NOT warn for a lifetime used twice in an impl.
+//
+// compile-pass
+
 #![deny(single_use_lifetime)]
-struct Foo<'x> { //~ ERROR lifetime name `'x` only used once
-    x: &'x u32 // no warning!
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+struct Foo<'f> {
+    data: &'f u32
 }
 
-// Once #44524 is fixed, this should issue a warning.
-impl<'y> Foo<'y> { //~ ERROR lifetime name `'y` only used once
-    fn method() { }
+impl<'f> Foo<'f> {
+    fn inherent_a(&self, data: &'f u32) {
+    }
 }
 
 fn main() { }

src/test/ui/single-use-lifetime/two-uses-in-inherent-method-argument-and-return.rs

@@ -0,0 +1,28 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that we DO NOT warn for a lifetime used twice in an impl method and
+// header.
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+    fn inherent_a<'a>(&self, data: &'a u32) -> &'a u32{
+      data
+    }
+}
+
+fn main() { }

src/test/ui/single-use-lifetime/two-uses-in-inherent-method-argument-and-return.stderr

@@ -0,0 +1,14 @@
+error: lifetime parameter `'f` only used once
+  --> $DIR/two-uses-in-inherent-method-argument-and-return.rs:22:6
+   |
+LL | impl<'f> Foo<'f> { //~ ERROR `'f` only used once
+   |      ^^
+   |
+note: lint level defined here
+  --> $DIR/two-uses-in-inherent-method-argument-and-return.rs:14:9
+   |
+LL | #![deny(single_use_lifetime)]
+   |         ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+

src/test/ui/single-use-lifetime/two-uses-in-trait-impl.rs

@@ -0,0 +1,32 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that we DO NOT warn for a lifetime on an impl used in both
+// header and in an associated type.
+//
+// compile-pass
+
+#![deny(single_use_lifetime)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+struct Foo<'f> {
+    data: &'f u32
+}
+
+impl<'f> Iterator for Foo<'f> {
+    type Item = &'f u32;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        None
+    }
+}
+
+fn main() { }