Auto merge of #29532 - Ryman:cow_path, r=alexcrichton

src/libcollections/string.rs

@@ -963,7 +963,7 @@ impl PartialEq for String {
 macro_rules! impl_eq {
     ($lhs:ty, $rhs: ty) => {
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl<'a> PartialEq<$rhs> for $lhs {
+        impl<'a, 'b> PartialEq<$rhs> for $lhs {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool { PartialEq::eq(&self[..], &other[..]) }
             #[inline]
@@ -971,7 +971,7 @@ macro_rules! impl_eq {
         }
 
         #[stable(feature = "rust1", since = "1.0.0")]
-        impl<'a> PartialEq<$lhs> for $rhs {
+        impl<'a, 'b> PartialEq<$lhs> for $rhs {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool { PartialEq::eq(&self[..], &other[..]) }
             #[inline]
@@ -984,24 +984,9 @@ macro_rules! impl_eq {
 impl_eq! { String, str }
 impl_eq! { String, &'a str }
 impl_eq! { Cow<'a, str>, str }
+impl_eq! { Cow<'a, str>, &'b str }
 impl_eq! { Cow<'a, str>, String }
 
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b> PartialEq<&'b str> for Cow<'a, str> {
-    #[inline]
-    fn eq(&self, other: &&'b str) -> bool { PartialEq::eq(&self[..], &other[..]) }
-    #[inline]
-    fn ne(&self, other: &&'b str) -> bool { PartialEq::ne(&self[..], &other[..]) }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl<'a, 'b> PartialEq<Cow<'a, str>> for &'b str {
-    #[inline]
-    fn eq(&self, other: &Cow<'a, str>) -> bool { PartialEq::eq(&self[..], &other[..]) }
-    #[inline]
-    fn ne(&self, other: &Cow<'a, str>) -> bool { PartialEq::ne(&self[..], &other[..]) }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Default for String {
     #[inline]

src/libstd/path.rs

@@ -1166,6 +1166,22 @@ impl<'a> IntoCow<'a, Path> for &'a Path {
     }
 }
 
+#[stable(feature = "cow_from_path", since = "1.6.0")]
+impl<'a> From<&'a Path> for Cow<'a, Path> {
+    #[inline]
+    fn from(s: &'a Path) -> Cow<'a, Path> {
+        Cow::Borrowed(s)
+    }
+}
+
+#[stable(feature = "cow_from_path", since = "1.6.0")]
+impl<'a> From<PathBuf> for Cow<'a, Path> {
+    #[inline]
+    fn from(s: PathBuf) -> Cow<'a, Path> {
+        Cow::Owned(s)
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl ToOwned for Path {
     type Owned = PathBuf;
@@ -1893,6 +1909,29 @@ impl<'a> IntoIterator for &'a Path {
     fn into_iter(self) -> Iter<'a> { self.iter() }
 }
 
+macro_rules! impl_eq {
+    ($lhs:ty, $rhs: ty) => {
+        #[stable(feature = "partialeq_path", since = "1.6.0")]
+        impl<'a, 'b> PartialEq<$rhs> for $lhs {
+            #[inline]
+            fn eq(&self, other: &$rhs) -> bool { <Path as PartialEq>::eq(self, other) }
+        }
+
+        #[stable(feature = "partialeq_path", since = "1.6.0")]
+        impl<'a, 'b> PartialEq<$lhs> for $rhs {
+            #[inline]
+            fn eq(&self, other: &$lhs) -> bool { <Path as PartialEq>::eq(self, other) }
+        }
+
+    }
+}
+
+impl_eq!(PathBuf, Path);
+impl_eq!(PathBuf, &'a Path);
+impl_eq!(Cow<'a, Path>, Path);
+impl_eq!(Cow<'a, Path>, &'b Path);
+impl_eq!(Cow<'a, Path>, PathBuf);
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -2002,6 +2041,26 @@ mod tests {
         assert_eq!(static_cow_path, owned_cow_path);
     }
 
+    #[test]
+    fn into() {
+        use borrow::Cow;
+
+        let static_path = Path::new("/home/foo");
+        let static_cow_path: Cow<'static, Path> = static_path.into();
+        let pathbuf = PathBuf::from("/home/foo");
+
+        {
+            let path: &Path = &pathbuf;
+            let borrowed_cow_path: Cow<Path> = path.into();
+
+            assert_eq!(static_cow_path, borrowed_cow_path);
+        }
+
+        let owned_cow_path: Cow<'static, Path> = pathbuf.into();
+
+        assert_eq!(static_cow_path, owned_cow_path);
+    }
+
     #[test]
     #[cfg(unix)]
     pub fn test_decompositions_unix() {
@@ -3070,6 +3129,31 @@ mod tests {
         tfe!("/", "foo", "/", false);
     }
 
+    #[test]
+    fn test_eq_recievers() {
+        use borrow::Cow;
+
+        let borrowed: &Path = Path::new("foo/bar");
+        let mut owned: PathBuf = PathBuf::new();
+        owned.push("foo");
+        owned.push("bar");
+        let borrowed_cow: Cow<Path> = borrowed.into();
+        let owned_cow: Cow<Path> = owned.clone().into();
+
+        macro_rules! t {
+            ($($current:expr),+) => {
+                $(
+                    assert_eq!($current, borrowed);
+                    assert_eq!($current, owned);
+                    assert_eq!($current, borrowed_cow);
+                    assert_eq!($current, owned_cow);
+                )+
+            }
+        }
+
+        t!(borrowed, owned, borrowed_cow, owned_cow);
+    }
+
     #[test]
     pub fn test_compare() {
         use hash::{Hash, Hasher, SipHasher};