Auto merge of #49304 - sinkuu:impl_trait_rustdoc, r=QuietMisdreavus

Rustdoc support for universal_impl_trait

Hides type parameters synthesized by `impl Trait`-in-argument-position, and enables links to trait names.

<img alt="before" src="https://user-images.githubusercontent.com/7091080/37831646-a61413c6-2ee9-11e8-8ec2-a6137956d922.png" width="450"/>
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<img alt="after" src="https://user-images.githubusercontent.com/7091080/37831657-b2ff0ae6-2ee9-11e8-8797-fdad904782bf.png" width="450"/>

Fixes #49309

1 files changed, 46 insertions, 0 deletions

diff --git a/src/test/rustdoc/universal-impl-trait.rs b/src/test/rustdoc/universal-impl-trait.rs
new file mode 100644
index 00000000000..4cf99562c52
--- /dev/null
+++ b/src/test/rustdoc/universal-impl-trait.rs
@@ -0,0 +1,46 @@
+// Copyright 2018 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(universal_impl_trait)]
+#![crate_name = "foo"]
+
+// @has foo/fn.foo.html
+// @has - //pre 'foo('
+// @matches - '_x: impl <a class="trait" href="[^"]+/trait\.Clone\.html"'
+// @matches - '_z: .+impl.+trait\.Copy\.html.+, impl.+trait\.Clone\.html'
+pub fn foo(_x: impl Clone, _y: i32, _z: (impl Copy, impl Clone)) {
+}
+
+pub trait Trait {
+    // @has foo/trait.Trait.html
+    // @has - 'method</a>('
+    // @matches - '_x: impl <a class="trait" href="[^"]+/trait\.Debug\.html"'
+    fn method(&self, _x: impl std::fmt::Debug) {
+    }
+}
+
+pub struct S<T>(T);
+
+impl<T> S<T> {
+    // @has foo/struct.S.html
+    // @has - 'bar</a>('
+    // @matches - '_bar: impl <a class="trait" href="[^"]+/trait\.Copy\.html"'
+    pub fn bar(_bar: impl Copy) {
+    }
+
+    // @has - 'baz</a>('
+    // @matches - '_baz:.+struct\.S\.html.+impl .+trait\.Clone\.html'
+    pub fn baz(_baz: S<impl Clone>) {
+    }
+}
+
+// @has - 'method</a>('
+// @matches - '_x: impl <a class="trait" href="[^"]+/trait\.Debug\.html"'
+impl<T> Trait for S<T> {}