Add more tests.

src/test/ui/traits/trait-alias-fail.stderr

@@ -1,38 +0,0 @@
-error: type parameters on the left side of a trait alias cannot be bounded
-  --> $DIR/trait-alias-fail.rs:14:14
-   |
-LL | trait Alias2<T: Clone = ()> = Default;
-   |              ^
-
-error: type parameters on the left side of a trait alias cannot have defaults
-  --> $DIR/trait-alias-fail.rs:14:14
-   |
-LL | trait Alias2<T: Clone = ()> = Default;
-   |              ^
-
-error[E0404]: expected trait, found trait alias `Alias1`
-  --> $DIR/trait-alias-fail.rs:18:6
-   |
-LL | impl Alias1 for () {}
-   |      ^^^^^^ not a trait
-
-error[E0658]: trait aliases are experimental (see issue #41517)
-  --> $DIR/trait-alias-fail.rs:13:1
-   |
-LL | trait Alias1<T> = Default where T: Clone;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: add #![feature(trait_alias)] to the crate attributes to enable
-
-error[E0658]: trait aliases are experimental (see issue #41517)
-  --> $DIR/trait-alias-fail.rs:14:1
-   |
-LL | trait Alias2<T: Clone = ()> = Default;
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = help: add #![feature(trait_alias)] to the crate attributes to enable
-
-error: aborting due to 5 previous errors
-
-Some errors occurred: E0404, E0658.
-For more information about an error, try `rustc --explain E0404`.

src/test/ui/traits/trait-alias-fail1.rs

@@ -10,11 +10,12 @@
 
 // gate-test-trait_alias
 
-trait Alias1<T> = Default where T: Clone;
-trait Alias2<T: Clone = ()> = Default;
+trait CloneDefault<T> = Default where T: Clone;
+trait BoundedAlias<T: Clone = ()> = Default;
 
-impl Alias1 {}
+trait A<T: Send> {}
+trait B<T> = A<T>; // FIXME: parameter T should need a bound here, or semantics should be changed
 
-impl Alias1 for () {}
+impl CloneDefault for () {}
 
 fn main() {}

src/test/ui/traits/trait-alias-fail1.stderr

@@ -0,0 +1,46 @@
+error: type parameters on the left side of a trait alias cannot be bounded
+  --> $DIR/trait-alias-fail1.rs:14:20
+   |
+LL | trait BoundedAlias<T: Clone = ()> = Default;
+   |                    ^
+
+error: type parameters on the left side of a trait alias cannot have defaults
+  --> $DIR/trait-alias-fail1.rs:14:20
+   |
+LL | trait BoundedAlias<T: Clone = ()> = Default;
+   |                    ^
+
+error[E0404]: expected trait, found trait alias `CloneDefault`
+  --> $DIR/trait-alias-fail1.rs:19:6
+   |
+LL | impl CloneDefault for () {}
+   |      ^^^^^^^^^^^^ not a trait
+
+error[E0658]: trait aliases are experimental (see issue #41517)
+  --> $DIR/trait-alias-fail1.rs:13:1
+   |
+LL | trait CloneDefault<T> = Default where T: Clone;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(trait_alias)] to the crate attributes to enable
+
+error[E0658]: trait aliases are experimental (see issue #41517)
+  --> $DIR/trait-alias-fail1.rs:14:1
+   |
+LL | trait BoundedAlias<T: Clone = ()> = Default;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(trait_alias)] to the crate attributes to enable
+
+error[E0658]: trait aliases are experimental (see issue #41517)
+  --> $DIR/trait-alias-fail1.rs:17:1
+   |
+LL | trait B<T> = A<T>; // FIXME: this should not work... or should it?
+   | ^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(trait_alias)] to the crate attributes to enable
+
+error: aborting due to 6 previous errors
+
+Some errors occurred: E0404, E0658.
+For more information about an error, try `rustc --explain E0404`.

src/test/ui/traits/trait-alias-fail2.rs

@@ -0,0 +1,19 @@
+// 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.
+
+// gate-test-trait_alias
+
+trait EqAlias = Eq;
+trait IteratorAlias = Iterator;
+
+fn main() {
+    let _: &dyn EqAlias = &123;
+    let _: &dyn IteratorAlias = &vec![123].into_iter();
+}

src/test/ui/traits/trait-alias-fail2.stderr

@@ -0,0 +1,19 @@
+error[E0658]: trait aliases are experimental (see issue #41517)
+  --> $DIR/trait-alias-fail2.rs:13:1
+   |
+LL | trait EqAlias = Eq;
+   | ^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(trait_alias)] to the crate attributes to enable
+
+error[E0658]: trait aliases are experimental (see issue #41517)
+  --> $DIR/trait-alias-fail2.rs:14:1
+   |
+LL | trait IteratorAlias = Iterator;
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add #![feature(trait_alias)] to the crate attributes to enable
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0658`.