ArrayString: Add PartialEq, Eq, Hash, and tests

src/array_string.rs

@@ -1,6 +1,6 @@
 use std::borrow::Borrow;
 use std::fmt;
-use std::mem;
+use std::hash::{Hash, Hasher};
 use std::ops::Deref;
 use std::str;
 use std::slice;
@@ -22,14 +22,6 @@ pub struct ArrayString<A: Array<Item=u8>> {
     len: A::Index,
 }
 
-unsafe fn new_array<A: Array<Item=u8>>() -> A {
-    // Note: Returning an uninitialized value here only works
-    // if we can be sure the data is never used. The nullable pointer
-    // inside enum optimization conflicts with this this for example,
-    // so we need to be extra careful. See `NoDrop` enum.
-    mem::uninitialized()
-}
-
 impl<A: Array<Item=u8>> ArrayString<A> {
     /// Create a new empty `ArrayString`.
     ///
@@ -46,7 +38,7 @@ impl<A: Array<Item=u8>> ArrayString<A> {
     pub fn new() -> ArrayString<A> {
         unsafe {
             ArrayString {
-                xs: new_array(),
+                xs: ::new_array(),
                 len: Index::from(0),
             }
         }
@@ -150,6 +142,32 @@ impl<A: Array<Item=u8>> Deref for ArrayString<A> {
     }
 }
 
+impl<A: Array<Item=u8>> PartialEq for ArrayString<A> {
+    fn eq(&self, rhs: &Self) -> bool {
+        **self == **rhs
+    }
+}
+
+impl<A: Array<Item=u8>> PartialEq<str> for ArrayString<A> {
+    fn eq(&self, rhs: &str) -> bool {
+        &**self == rhs
+    }
+}
+
+impl<A: Array<Item=u8>> PartialEq<ArrayString<A>> for str {
+    fn eq(&self, rhs: &ArrayString<A>) -> bool {
+        self == &**rhs
+    }
+}
+
+impl<A: Array<Item=u8>> Eq for ArrayString<A> { }
+
+impl<A: Array<Item=u8>> Hash for ArrayString<A> {
+    fn hash<H: Hasher>(&self, h: &mut H) {
+        (**self).hash(h)
+    }
+}
+
 impl<A: Array<Item=u8>> Borrow<str> for ArrayString<A> {
     fn borrow(&self) -> &str { self }
 }
@@ -158,7 +176,11 @@ impl<A: Array<Item=u8>> AsRef<str> for ArrayString<A> {
     fn as_ref(&self) -> &str { self }
 }
 
-impl<A: Array<Item=u8>> fmt::Debug for ArrayString<A> where A::Item: fmt::Debug {
+impl<A: Array<Item=u8>> fmt::Debug for ArrayString<A> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) }
+}
+
+impl<A: Array<Item=u8>> fmt::Display for ArrayString<A> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) }
 }
 
@@ -174,4 +196,3 @@ impl<A: Array<Item=u8> + Copy> Clone for ArrayString<A> {
         *self
     }
 }
-

tests/tests.rs

@@ -1,8 +1,11 @@
 extern crate arrayvec;
 
 use arrayvec::ArrayVec;
+use arrayvec::ArrayString;
 use std::mem;
 
+use std::collections::HashMap;
+
 
 #[test]
 fn test_simple() {
@@ -260,3 +263,21 @@ fn test_write() {
     assert_eq!(r, 5);
     assert_eq!(&v[..], &[1, 2, 3, 9, 9, 9, 9, 9]);
 }
+
+#[test]
+fn test_string() {
+    let text = "hello world";
+    let mut s = ArrayString::<[_; 16]>::new();
+    s.push_str(text).unwrap();
+    assert_eq!(&s, text);
+    assert_eq!(text, &s);
+
+    // Make sure Hash / Eq / Borrow match up so we can use HashMap
+    let mut map = HashMap::new();
+    map.insert(s, 1);
+    assert_eq!(map[text], 1);
+
+    let mut t = ArrayString::<[_; 2]>::new();
+    assert!(t.push_str(text).is_err());
+    assert_eq!(&t, "");
+}