Add resize method

Fixes #82.

Author: mbrubeck

lib.rs

@@ -39,7 +39,7 @@ use std::borrow::{Borrow, BorrowMut};
 use std::cmp;
 use std::fmt;
 use std::hash::{Hash, Hasher};
-use std::iter::{IntoIterator, FromIterator};
+use std::iter::{IntoIterator, FromIterator, repeat};
 use std::mem;
 use std::ops;
 use std::ptr;
@@ -731,6 +731,24 @@ impl<A: Array> SmallVec<A> where A::Item: Copy {
     }
 }
 
+impl<A: Array> SmallVec<A> where A::Item: Clone {
+    /// Resizes the vector so that its length is equal to `len`.
+    ///
+    /// If `len` is less than the current length, the vector simply truncated.
+    ///
+    /// If `len` is greater than the current length, `value` is appended to the
+    /// vector until its length equals `len`.
+    pub fn resize(&mut self, len: usize, value: A::Item) {
+        let old_len = self.len();
+
+        if len > old_len {
+            self.extend(repeat(value).take(len - old_len));
+        } else {
+            self.truncate(len);
+        }
+    }
+}
+
 impl<A: Array> ops::Deref for SmallVec<A> {
     type Target = [A::Item];
     #[inline]
@@ -1733,6 +1751,17 @@ mod tests {
         assert_eq!(no_dupes.len(), 5);
     }
 
+    #[test]
+    fn test_resize() {
+        let mut v: SmallVec<[i32; 8]> = SmallVec::new();
+        v.push(1);
+        v.resize(5, 0);
+        assert_eq!(v[..], [1, 0, 0, 0, 0][..]);
+
+        v.resize(2, -1);
+        assert_eq!(v[..], [1, 0][..]);
+    }
+
     #[cfg(feature = "std")]
     #[test]
     fn test_write() {