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
:(.)

1 files changed, 13 insertions, 44 deletions

diff --git a/src/libcollections/btree.rs b/src/libcollections/btree.rs
index 6411b6bc974..3f53ede6027 100644
--- a/src/libcollections/btree.rs
+++ b/src/libcollections/btree.rs
@@ -94,17 +94,12 @@ impl<K: Clone + TotalOrd, V: Clone> Clone for BTree<K, V> {
 
 impl<K: TotalOrd, V: TotalEq> Eq for BTree<K, V> {
     fn eq(&self, other: &BTree<K, V>) -> bool {
-        self.equals(other)
-    }
-}
-
-impl<K: TotalOrd, V: TotalEq> TotalEq for BTree<K, V> {
-    ///Testing equality on BTrees by comparing the root.
-    fn equals(&self, other: &BTree<K, V>) -> bool {
         self.root.cmp(&other.root) == Equal
     }
 }
 
+impl<K: TotalOrd, V: TotalEq> TotalEq for BTree<K, V> {}
+
 impl<K: TotalOrd, V: TotalEq> Ord for BTree<K, V> {
     fn lt(&self, other: &BTree<K, V>) -> bool {
         self.cmp(other) == Less
@@ -204,14 +199,6 @@ impl<K: Clone + TotalOrd, V: Clone> Clone for Node<K, V> {
 
 impl<K: TotalOrd, V: TotalEq> Eq for Node<K, V> {
     fn eq(&self, other: &Node<K, V>) -> bool {
-        self.equals(other)
-    }
-}
-
-impl<K: TotalOrd, V: TotalEq> TotalEq for Node<K, V> {
-    ///Returns whether two nodes are equal based on the keys of each element.
-    ///Two nodes are equal if all of their keys are the same.
-    fn equals(&self, other: &Node<K, V>) -> bool{
         match *self{
             BranchNode(ref branch) => {
                 if other.is_leaf() {
@@ -232,6 +219,8 @@ impl<K: TotalOrd, V: TotalEq> TotalEq for Node<K, V> {
     }
 }
 
+impl<K: TotalOrd, V: TotalEq> TotalEq for Node<K, V> {}
+
 impl<K: TotalOrd, V: TotalEq> Ord for Node<K, V> {
     fn lt(&self, other: &Node<K, V>) -> bool {
         self.cmp(other) == Less
@@ -405,16 +394,11 @@ impl<K: Clone + TotalOrd, V: Clone> Clone for Leaf<K, V> {
 
 impl<K: TotalOrd, V: TotalEq> Eq for Leaf<K, V> {
     fn eq(&self, other: &Leaf<K, V>) -> bool {
-        self.equals(other)
+        self.elts == other.elts
     }
 }
 
-impl<K: TotalOrd, V: TotalEq> TotalEq for Leaf<K, V> {
-    ///Implementation of equals function for leaves that compares LeafElts.
-    fn equals(&self, other: &Leaf<K, V>) -> bool {
-        self.elts.equals(&other.elts)
-    }
-}
+impl<K: TotalOrd, V: TotalEq> TotalEq for Leaf<K, V> {}
 
 impl<K: TotalOrd, V: TotalEq> Ord for Leaf<K, V> {
     fn lt(&self, other: &Leaf<K, V>) -> bool {
@@ -639,16 +623,11 @@ impl<K: Clone + TotalOrd, V: Clone> Clone for Branch<K, V> {
 
 impl<K: TotalOrd, V: TotalEq> Eq for Branch<K, V> {
     fn eq(&self, other: &Branch<K, V>) -> bool {
-        self.equals(other)
+        self.elts == other.elts
     }
 }
 
-impl<K: TotalOrd, V: TotalEq> TotalEq for Branch<K, V> {
-    ///Equals function for Branches--compares all the elements in each branch
-    fn equals(&self, other: &Branch<K, V>) -> bool {
-        self.elts.equals(&other.elts)
-    }
-}
+impl<K: TotalOrd, V: TotalEq> TotalEq for Branch<K, V> {}
 
 impl<K: TotalOrd, V: TotalEq> Ord for Branch<K, V> {
     fn lt(&self, other: &Branch<K, V>) -> bool {
@@ -712,16 +691,11 @@ impl<K: Clone + TotalOrd, V: Clone> Clone for LeafElt<K, V> {
 
 impl<K: TotalOrd, V: TotalEq> Eq for LeafElt<K, V> {
     fn eq(&self, other: &LeafElt<K, V>) -> bool {
-        self.equals(other)
+        self.key == other.key && self.value == other.value
     }
 }
 
-impl<K: TotalOrd, V: TotalEq> TotalEq for LeafElt<K, V> {
-    ///TotalEq for LeafElts
-    fn equals(&self, other: &LeafElt<K, V>) -> bool {
-        self.key.equals(&other.key) && self.value.equals(&other.value)
-    }
-}
+impl<K: TotalOrd, V: TotalEq> TotalEq for LeafElt<K, V> {}
 
 impl<K: TotalOrd, V: TotalEq> Ord for LeafElt<K, V> {
     fn lt(&self, other: &LeafElt<K, V>) -> bool {
@@ -766,16 +740,11 @@ impl<K: Clone + TotalOrd, V: Clone> Clone for BranchElt<K, V> {
 
 impl<K: TotalOrd, V: TotalEq> Eq for BranchElt<K, V>{
     fn eq(&self, other: &BranchElt<K, V>) -> bool {
-        self.equals(other)
+        self.key == other.key && self.value == other.value
     }
 }
 
-impl<K: TotalOrd, V: TotalEq> TotalEq for BranchElt<K, V>{
-    ///TotalEq for BranchElts
-    fn equals(&self, other: &BranchElt<K, V>) -> bool {
-        self.key.equals(&other.key)&&self.value.equals(&other.value)
-    }
-}
+impl<K: TotalOrd, V: TotalEq> TotalEq for BranchElt<K, V>{}
 
 impl<K: TotalOrd, V: TotalEq> Ord for BranchElt<K, V> {
     fn lt(&self, other: &BranchElt<K, V>) -> bool {
@@ -900,7 +869,7 @@ mod test_btree {
     fn btree_clone_test() {
         let b = BTree::new(1, ~"abc", 2);
         let b2 = b.clone();
-        assert!(b.root.equals(&b2.root))
+        assert!(b.root == b2.root)
     }
 
     //Tests the BTree's cmp() method when one node is "less than" another.