stabilized vec_splice (fixes rust-lang#32310)

Author: budziq

src/doc/unstable-book/src/library-features/splice.md

@@ -6,8 +6,8 @@ The tracking issue for this feature is: [#32310]
 
 ------------------------
 
-The `splice()` method on `Vec` and `String` allows you to replace a range
-of values in a vector or string with another range of values, and returns
+The `splice()` method on `String` allows you to replace a range
+of values in a string with another range of values, and returns
 the replaced values.
 
 A simple example:
@@ -21,4 +21,4 @@ let beta_offset = s.find('β').unwrap_or(s.len());
 let t: String = s.splice(..beta_offset, "Α is capital alpha; ").collect();
 assert_eq!(t, "α is alpha, ");
 assert_eq!(s, "Α is capital alpha; β is beta");
-```
+```

src/liballoc/vec.rs

@@ -1942,15 +1942,14 @@ impl<T> Vec<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(splice)]
     /// let mut v = vec![1, 2, 3];
     /// let new = [7, 8];
     /// let u: Vec<_> = v.splice(..2, new.iter().cloned()).collect();
     /// assert_eq!(v, &[7, 8, 3]);
     /// assert_eq!(u, &[1, 2]);
     /// ```
     #[inline]
-    #[unstable(feature = "splice", reason = "recently added", issue = "32310")]
+    #[stable(feature = "vec_splice", since = "1.22.0")]
     pub fn splice<R, I>(&mut self, range: R, replace_with: I) -> Splice<I::IntoIter>
         where R: RangeArgument<usize>, I: IntoIterator<Item=T>
     {
@@ -2550,13 +2549,13 @@ impl<'a, T> InPlace<T> for PlaceBack<'a, T> {
 /// [`splice()`]: struct.Vec.html#method.splice
 /// [`Vec`]: struct.Vec.html
 #[derive(Debug)]
-#[unstable(feature = "splice", reason = "recently added", issue = "32310")]
+#[stable(feature = "vec_splice", since = "1.22.0")]
 pub struct Splice<'a, I: Iterator + 'a> {
     drain: Drain<'a, I::Item>,
     replace_with: I,
 }
 
-#[unstable(feature = "splice", reason = "recently added", issue = "32310")]
+#[stable(feature = "vec_splice", since = "1.22.0")]
 impl<'a, I: Iterator> Iterator for Splice<'a, I> {
     type Item = I::Item;
 
@@ -2569,18 +2568,18 @@ impl<'a, I: Iterator> Iterator for Splice<'a, I> {
     }
 }
 
-#[unstable(feature = "splice", reason = "recently added", issue = "32310")]
+#[stable(feature = "vec_splice", since = "1.22.0")]
 impl<'a, I: Iterator> DoubleEndedIterator for Splice<'a, I> {
     fn next_back(&mut self) -> Option<Self::Item> {
         self.drain.next_back()
     }
 }
 
-#[unstable(feature = "splice", reason = "recently added", issue = "32310")]
+#[stable(feature = "vec_splice", since = "1.22.0")]
 impl<'a, I: Iterator> ExactSizeIterator for Splice<'a, I> {}
 
 
-#[unstable(feature = "splice", reason = "recently added", issue = "32310")]
+#[stable(feature = "vec_splice", since = "1.22.0")]
 impl<'a, I: Iterator> Drop for Splice<'a, I> {
     fn drop(&mut self) {
         // exhaust drain first