collections: impl Deref for Vec/String

This commit adds the following impls:

    impl<T> Deref<[T]> for Vec<T>
    impl<T> DerefMut<[T]> for Vec<T>
    impl Deref<str> for String

This commit also removes all duplicated inherent methods from vectors and
strings as implementations will now silently call through to the slice
implementation. Some breakage occurred at std and beneath due to inherent
methods removed in favor of those in the slice traits and std doesn't use its
own prelude,

cc #18424

Author: alexcrichton

src/libcollections/str.rs

@@ -1677,40 +1677,6 @@ mod tests {
         assert_eq!(pos, p.len());
     }
 
-    #[test]
-    fn test_split_char_iterator() {
-        let data = "\nMäry häd ä little lämb\nLittle lämb\n";
-
-        let split: Vec<&str> = data.split(' ').collect();
-        assert_eq!( split, vec!["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);
-
-        let mut rsplit: Vec<&str> = data.split(' ').rev().collect();
-        rsplit.reverse();
-        assert_eq!(rsplit, vec!["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);
-
-        let split: Vec<&str> = data.split(|c: char| c == ' ').collect();
-        assert_eq!( split, vec!["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);
-
-        let mut rsplit: Vec<&str> = data.split(|c: char| c == ' ').rev().collect();
-        rsplit.reverse();
-        assert_eq!(rsplit, vec!["\nMäry", "häd", "ä", "little", "lämb\nLittle", "lämb\n"]);
-
-        // Unicode
-        let split: Vec<&str> = data.split('ä').collect();
-        assert_eq!( split, vec!["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);
-
-        let mut rsplit: Vec<&str> = data.split('ä').rev().collect();
-        rsplit.reverse();
-        assert_eq!(rsplit, vec!["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);
-
-        let split: Vec<&str> = data.split(|c: char| c == 'ä').collect();
-        assert_eq!( split, vec!["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);
-
-        let mut rsplit: Vec<&str> = data.split(|c: char| c == 'ä').rev().collect();
-        rsplit.reverse();
-        assert_eq!(rsplit, vec!["\nM", "ry h", "d ", " little l", "mb\nLittle l", "mb\n"]);
-    }
-
     #[test]
     fn test_splitn_char_iterator() {
         let data = "\nMäry häd ä little lämb\nLittle lämb\n";
@@ -1729,28 +1695,6 @@ mod tests {
         assert_eq!(split, vec!["\nM", "ry h", "d ", " little lämb\nLittle lämb\n"]);
     }
 
-    #[test]
-    fn test_rsplitn_char_iterator() {
-        let data = "\nMäry häd ä little lämb\nLittle lämb\n";
-
-        let mut split: Vec<&str> = data.rsplitn(3, ' ').collect();
-        split.reverse();
-        assert_eq!(split, vec!["\nMäry häd ä", "little", "lämb\nLittle", "lämb\n"]);
-
-        let mut split: Vec<&str> = data.rsplitn(3, |c: char| c == ' ').collect();
-        split.reverse();
-        assert_eq!(split, vec!["\nMäry häd ä", "little", "lämb\nLittle", "lämb\n"]);
-
-        // Unicode
-        let mut split: Vec<&str> = data.rsplitn(3, 'ä').collect();
-        split.reverse();
-        assert_eq!(split, vec!["\nMäry häd ", " little l", "mb\nLittle l", "mb\n"]);
-
-        let mut split: Vec<&str> = data.rsplitn(3, |c: char| c == 'ä').collect();
-        split.reverse();
-        assert_eq!(split, vec!["\nMäry häd ", " little l", "mb\nLittle l", "mb\n"]);
-    }
-
     #[test]
     fn test_split_char_iterator_no_trailing() {
         let data = "\nMäry häd ä little lämb\nLittle lämb\n";
@@ -1762,19 +1706,6 @@ mod tests {
         assert_eq!(split, vec!["", "Märy häd ä little lämb", "Little lämb"]);
     }
 
-    #[test]
-    fn test_rev_split_char_iterator_no_trailing() {
-        let data = "\nMäry häd ä little lämb\nLittle lämb\n";
-
-        let mut split: Vec<&str> = data.split('\n').rev().collect();
-        split.reverse();
-        assert_eq!(split, vec!["", "Märy häd ä little lämb", "Little lämb", ""]);
-
-        let mut split: Vec<&str> = data.split_terminator('\n').rev().collect();
-        split.reverse();
-        assert_eq!(split, vec!["", "Märy häd ä little lämb", "Little lämb"]);
-    }
-
     #[test]
     fn test_words() {
         let data = "\n \tMäry   häd\tä  little lämb\nLittle lämb\n";

src/libcollections/string.rs

@@ -744,6 +744,11 @@ impl ops::Slice<uint, str> for String {
     }
 }
 
+#[experimental = "waiting on Deref stabilization"]
+impl ops::Deref<str> for String {
+    fn deref<'a>(&'a self) -> &'a str { self.as_slice() }
+}
+
 /// Wrapper type providing a `&String` reference via `Deref`.
 #[experimental]
 pub struct DerefString<'a> {