auto merge of #13102 : huonw/rust/totaleq-deriving, r=thestinger

std: remove the `equals` method from `TotalEq`.

`TotalEq` is now just an assertion about the `Eq` impl of a
type (i.e. `==` is a total equality if a type implements `TotalEq`) so
the extra method is just confusing.

Also, a new method magically appeared as a hack to allow deriving to
assert that the contents of a struct/enum are also TotalEq, because the
deriving infrastructure makes it very hard to do anything but create a
trait method. (You didn't hear about this horrible work-around from me
:(.)

src/test/run-pass/deriving-cmp-generic-enum.rs

@@ -39,9 +39,6 @@ pub fn main() {
             assert_eq!(*e1 == *e2, eq);
             assert_eq!(*e1 != *e2, !eq);
 
-            // TotalEq
-            assert_eq!(e1.equals(e2), eq);
-
             // Ord
             assert_eq!(*e1 < *e2, lt);
             assert_eq!(*e1 > *e2, gt);

src/test/run-pass/deriving-cmp-generic-struct-enum.rs

@@ -35,9 +35,6 @@ pub fn main() {
             assert_eq!(*es1 == *es2, eq);
             assert_eq!(*es1 != *es2, !eq);
 
-            // TotalEq
-            assert_eq!(es1.equals(es2), eq);
-
             // Ord
             assert_eq!(*es1 < *es2, lt);
             assert_eq!(*es1 > *es2, gt);

src/test/run-pass/deriving-cmp-generic-struct.rs

@@ -35,9 +35,6 @@ pub fn main() {
             assert_eq!(*s1 == *s2, eq);
             assert_eq!(*s1 != *s2, !eq);
 
-            // TotalEq
-            assert_eq!(s1.equals(s2), eq);
-
             // Ord
             assert_eq!(*s1 < *s2, lt);
             assert_eq!(*s1 > *s2, gt);

src/test/run-pass/deriving-cmp-generic-tuple-struct.rs

@@ -33,9 +33,6 @@ pub fn main() {
             assert_eq!(*ts1 == *ts2, eq);
             assert_eq!(*ts1 != *ts2, !eq);
 
-            // TotalEq
-            assert_eq!(ts1.equals(ts2), eq);
-
             // Ord
             assert_eq!(*ts1 < *ts2, lt);
             assert_eq!(*ts1 > *ts2, gt);

src/test/run-pass/deriving-cmp-shortcircuit.rs

@@ -21,9 +21,7 @@ impl Ord for FailCmp {
     fn lt(&self, _: &FailCmp) -> bool { fail!("lt") }
 }
 
-impl TotalEq for FailCmp {
-    fn equals(&self, _: &FailCmp) -> bool { fail!("equals") }
-}
+impl TotalEq for FailCmp {}
 
 impl TotalOrd for FailCmp {
     fn cmp(&self, _: &FailCmp) -> Ordering { fail!("cmp") }
@@ -41,6 +39,5 @@ pub fn main() {
 
     assert!(a != b);
     assert!(a < b);
-    assert!(!a.equals(&b));
     assert_eq!(a.cmp(&b), ::std::cmp::Less);
 }

src/test/run-pass/deriving-self-lifetime-totalord-totaleq.rs

@@ -19,10 +19,6 @@ struct A<'a> {
 pub fn main() {
     let (a, b) = (A { x: &1 }, A { x: &2 });
 
-    assert!(a.equals(&a));
-    assert!(b.equals(&b));
-
-
     assert_eq!(a.cmp(&a), Equal);
     assert_eq!(b.cmp(&b), Equal);