Generalize the code so we can handle multiple supertraits.

Fixes #10596. Fixes #22279.

src/test/compile-fail/issue-3953.rs

@@ -1,33 +0,0 @@
-// Copyright 2012 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.
-
-// ignore-tidy-linelength
-
-use std::cmp::PartialEq;
-
-trait Hahaha: PartialEq + PartialEq {
-}
-
-struct Lol(isize);
-
-impl Hahaha for Lol { }
-
-impl PartialEq for Lol {
-    fn eq(&self, other: &Lol) -> bool { loop { } }
-    fn ne(&self, other: &Lol) -> bool { loop { } }
-}
-
-fn main() {
-    if Lol(2) == Lol(4) {
-        println!("2 == 4");
-    } else {
-        println!("2 != 4");
-    }
-}

src/test/compile-fail/traits-repeated-supertrait-ambig.rs

@@ -0,0 +1,53 @@
+// 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 a case of a trait which extends the same supertrait twice, but
+// with difference type parameters. Test then that when we don't give
+// enough information to pick between these, no selection is made. In
+// this particular case, the two choices are i64/u64 -- so when we use
+// an integer literal, we wind up falling this literal back to i32.
+// See also `run-pass/trait-repeated-supertrait.rs`.
+
+trait CompareTo<T> {
+    fn same_as(&self, t: T) -> bool;
+}
+
+trait CompareToInts : CompareTo<i64> + CompareTo<u64> {
+}
+
+impl CompareTo<i64> for i64 {
+    fn same_as(&self, t: i64) -> bool { *self == t }
+}
+
+impl CompareTo<u64> for i64 {
+    fn same_as(&self, t: u64) -> bool { *self == (t as i64) }
+}
+
+impl CompareToInts for i64 { }
+
+fn with_obj(c: &CompareToInts) -> bool {
+    c.same_as(22) //~ ERROR `CompareTo<i32>` is not implemented
+}
+
+fn with_trait<C:CompareToInts>(c: &C) -> bool {
+    c.same_as(22) //~ ERROR `CompareTo<i32>` is not implemented
+}
+
+fn with_ufcs1<C:CompareToInts>(c: &C) -> bool {
+    CompareToInts::same_as(c, 22) //~ ERROR `CompareTo<i32>` is not implemented
+}
+
+fn with_ufcs2<C:CompareToInts>(c: &C) -> bool {
+    CompareTo::same_as(c, 22) //~ ERROR `CompareTo<i32>` is not implemented
+}
+
+fn main() {
+    assert_eq!(22_i64.same_as(22), true); //~ ERROR `CompareTo<i32>` is not implemented
+}

src/test/compile-fail/unsized4.rs

@@ -1,19 +0,0 @@
-// 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 that bounds are sized-compatible.
-
-trait T : Sized {}
-fn f<Y: ?Sized + T>() {
-//~^ERROR incompatible bounds on `Y`, bound `T` does not allow unsized type
-}
-
-pub fn main() {
-}

src/test/run-pass/traits-repeated-supertrait.rs

@@ -0,0 +1,56 @@
+// 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 a case of a trait which extends the same supertrait twice, but
+// with difference type parameters. Test that we can invoke the
+// various methods in various ways successfully.
+// See also `compile-fail/trait-repeated-supertrait-ambig.rs`.
+
+trait CompareTo<T> {
+    fn same_as(&self, t: T) -> bool;
+}
+
+trait CompareToInts : CompareTo<i64> + CompareTo<u64> {
+}
+
+impl CompareTo<i64> for i64 {
+    fn same_as(&self, t: i64) -> bool { *self == t }
+}
+
+impl CompareTo<u64> for i64 {
+    fn same_as(&self, t: u64) -> bool { *self == (t as i64) }
+}
+
+impl CompareToInts for i64 { }
+
+fn with_obj(c: &CompareToInts) -> bool {
+    c.same_as(22_i64) && c.same_as(22_u64)
+}
+
+fn with_trait<C:CompareToInts>(c: &C) -> bool {
+    c.same_as(22_i64) && c.same_as(22_u64)
+}
+
+fn with_ufcs1<C:CompareToInts>(c: &C) -> bool {
+    CompareToInts::same_as(c, 22_i64) && CompareToInts::same_as(c, 22_u64)
+}
+
+fn with_ufcs2<C:CompareToInts>(c: &C) -> bool {
+    CompareTo::same_as(c, 22_i64) && CompareTo::same_as(c, 22_u64)
+}
+
+fn main() {
+    assert_eq!(22_i64.same_as(22_i64), true);
+    assert_eq!(22_i64.same_as(22_u64), true);
+    assert_eq!(with_trait(&22), true);
+    assert_eq!(with_obj(&22), true);
+    assert_eq!(with_ufcs1(&22), true);
+    assert_eq!(with_ufcs2(&22), true);
+}