Fix Equivalent traits for keys on Sets by removing default reflexive Equivalent impl.

src/map.rs

@@ -33,15 +33,6 @@ pub trait Equivalent<T>: Sized {
     fn matches(&self, other: &T) -> bool;
 }
 
-impl<T> Equivalent<T> for T
-where
-    T: PartialEq,
-{
-    fn matches(&self, other: &T) -> bool {
-        self == other
-    }
-}
-
 pub trait Hashes {
     fn hashed(&self) -> Hashed;
 }
@@ -376,6 +367,12 @@ impl<E: Hashes + PartialEq> Equivalent<E> for SetEntry<E> {
     }
 }
 
+impl<K, E: PartialEq + Hashes> Equivalent<K> for SetEntry<E> where K: Equivalent<E> {
+    fn matches(&self, other: &K) -> bool {
+        other.matches(&self.0.as_ref().unwrap())
+    }
+}
+
 impl<E: Hashes + PartialEq> Set<E> {
     pub fn resize(&mut self, len: usize) {
         self.0.resize(len)