Prohibit parenthesized params in bounds etc.

src/test/compile-fail/issue-32995-2.rs

@@ -0,0 +1,25 @@
+// 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.
+
+#![feature(conservative_impl_trait)]
+
+fn main() {
+    { fn f<X: ::std::marker()::Send>() {} }
+    //~^ ERROR parenthesized parameters may only be used with a trait
+
+    { fn f() -> impl ::std::marker()::Send { } }
+    //~^ ERROR parenthesized parameters may only be used with a trait
+}
+
+#[derive(Clone)]
+struct X;
+
+impl ::std::marker()::Copy for X {}
+//~^ ERROR parenthesized parameters may only be used with a trait

src/test/compile-fail/issue-32995.rs

@@ -17,6 +17,22 @@ fn main() {
 
     let b: ::std::boxed()::Box<_> = Box::new(1);
     //~^ ERROR parenthesized parameters may only be used with a trait
+
+    macro_rules! pathexpr {
+        ($p:path) => { $p }
+    }
+
+    let p = pathexpr!(::std::str()::from_utf8)(b"foo").unwrap();
+    //~^ ERROR parenthesized parameters may only be used with a trait
+
+    let p = pathexpr!(::std::str::from_utf8())(b"foo").unwrap();
+    //~^ ERROR parenthesized parameters may only be used with a trait
+
+    let o : Box<::std::marker()::Send> = Box::new(1);
+    //~^ ERROR parenthesized parameters may only be used with a trait
+
+    let o : Box<Send + ::std::marker()::Sync> = Box::new(1);
+    //~^ ERROR parenthesized parameters may only be used with a trait
 }
 
 fn foo<X:Default>() {