Add support for equality constraints on associated types

src/test/compile-fail/assoc-eq-1.rs

@@ -0,0 +1,27 @@
+// Copyright 2014 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 equality constraints on associated types. Check that unsupported syntax
+// does not ICE.
+
+#![feature(associated_types)]
+
+pub trait Foo {
+    type A;
+    fn boo(&self) -> <Self as Foo>::A;
+}
+
+fn foo2<I: Foo>(x: I) {
+    let _: A = x.boo(); //~ERROR use of undeclared
+    let _: I::A = x.boo(); //~ERROR failed to resolve
+    //~^ERROR use of undeclared type name `I::A`
+}
+
+pub fn main() {}

src/test/compile-fail/assoc-eq-2.rs

@@ -0,0 +1,30 @@
+// Copyright 2014 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 equality constraints on associated types. Check we get an error when an
+// equality constraint is used in a qualified path.
+
+#![feature(associated_types)]
+
+pub trait Foo {
+    type A;
+    fn boo(&self) -> <Self as Foo>::A;
+}
+
+struct Bar;
+
+impl Foo for int {
+    type A = uint;
+    fn boo(&self) -> uint { 42 }
+}
+
+fn baz<I: Foo>(x: &<I as Foo<A=Bar>>::A) {} //~ERROR equality constraints are not allowed in this
+
+pub fn main() {}

src/test/compile-fail/assoc-eq-3.rs

@@ -0,0 +1,48 @@
+// Copyright 2014 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 equality constraints on associated types. Check we get type errors
+// where we should.
+
+#![feature(associated_types)]
+
+pub trait Foo {
+    type A;
+    fn boo(&self) -> <Self as Foo>::A;
+}
+
+struct Bar;
+
+impl Foo for int {
+    type A = uint;
+    fn boo(&self) -> uint {
+        42
+    }
+}
+
+fn foo1<I: Foo<A=Bar>>(x: I) {
+    let _: Bar = x.boo();
+}
+
+fn foo2<I: Foo>(x: I) {
+    let _: Bar = x.boo(); //~ERROR mismatched types
+}
+
+
+pub fn baz(x: &Foo<A=Bar>) {
+    let _: Bar = x.boo();
+}
+
+
+pub fn main() {
+    let a = 42i;
+    foo1(a); //~ERROR the trait `Foo` is not implemented for the type `int`
+    baz(&a); //~ERROR the trait `Foo` is not implemented for the type `int`
+}

src/test/compile-fail/issue-3973.rs

@@ -31,6 +31,6 @@ impl ToString_ for Point {
 fn main() {
     let p = Point::new(0.0, 0.0);
     //~^ ERROR unresolved name `Point::new`
-    //~^^ ERROR failed to resolve. Use of undeclared module `Point`
+    //~^^ ERROR failed to resolve. Use of undeclared type or module `Point`
     println!("{}", p.to_string());
 }

src/test/compile-fail/macro-inner-attributes.rs

@@ -25,7 +25,7 @@ test!(b,
 #[qux]
 fn main() {
     a::bar();
-    //~^ ERROR failed to resolve. Use of undeclared module `a`
+    //~^ ERROR failed to resolve. Use of undeclared type or module `a`
     //~^^ ERROR unresolved name `a::bar`
     b::bar();
 }

src/test/run-pass/assoc-eq.rs

@@ -0,0 +1,55 @@
+// Copyright 2014 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 equality constraints on associated types.
+
+#![feature(associated_types)]
+
+pub trait Foo {
+    type A;
+    fn boo(&self) -> <Self as Foo>::A;
+}
+
+struct Bar;
+
+impl Foo for int {
+    type A = uint;
+    fn boo(&self) -> uint { 42 }
+}
+impl Foo for Bar {
+    type A = int;
+    fn boo(&self) -> int { 43 }
+}
+impl Foo for char {
+    type A = Bar;
+    fn boo(&self) -> Bar { Bar }
+}
+
+fn foo1<I: Foo<A=Bar>>(x: I) -> Bar {
+    x.boo()
+}
+fn foo2<I: Foo>(x: I) -> <I as Foo>::A {
+    x.boo()
+}
+fn baz(x: &Foo<A=Bar>) -> Bar {
+    x.boo()
+}
+
+pub fn main() {
+    let a = 42i;
+    assert!(foo2(a) == 42u);
+
+    let a = Bar;
+    assert!(foo2(a) == 43i);
+
+    let a = 'a';
+    foo1(a);
+    baz(&a);
+}