Add another test using projection types in impls.

Author: nikomatsakis

src/test/run-pass/associated-types-projection-from-known-type-in-impl.rs

@@ -0,0 +1,44 @@
+// Copyright 2015 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 where the impl self type uses a projection from a constant type.
+
+trait Int
+{
+    type T;
+}
+
+trait NonZero
+{
+    fn non_zero(self) -> bool;
+}
+
+impl Int for i32 { type T = i32; }
+impl Int for i64 { type T = i64; }
+impl Int for u32 { type T = u32; }
+impl Int for u64 { type T = u64; }
+
+impl NonZero for <i32 as Int>::T { fn non_zero(self) -> bool { self != 0 } }
+impl NonZero for <i64 as Int>::T { fn non_zero(self) -> bool { self != 0 } }
+impl NonZero for <u32 as Int>::T { fn non_zero(self) -> bool { self != 0 } }
+impl NonZero for <u64 as Int>::T { fn non_zero(self) -> bool { self != 0 } }
+
+fn main ()
+{
+    assert!(NonZero::non_zero(22_i32));
+    assert!(NonZero::non_zero(22_i64));
+    assert!(NonZero::non_zero(22_u32));
+    assert!(NonZero::non_zero(22_u64));
+
+    assert!(!NonZero::non_zero(0_i32));
+    assert!(!NonZero::non_zero(0_i64));
+    assert!(!NonZero::non_zero(0_u32));
+    assert!(!NonZero::non_zero(0_u64));
+}