diff --git a/src/libstd/smallintmap.rs b/src/libstd/smallintmap.rs
index 8dbd63478763..ffe52c4131e6 100644
--- a/src/libstd/smallintmap.rs
+++ b/src/libstd/smallintmap.rs
@@ -4,31 +4,31 @@ are O(highest integer key).
 "];
 import core::option;
 import core::option::{some, none};
+import dvec::{dvec, extensions};
 
 // FIXME: Should not be @; there's a bug somewhere in rustc that requires this
 // to be. (#2347)
-type smallintmap<T: copy> = @{mut v: [mut option<T>]};
+type smallintmap<T: copy> = @{v: dvec<option<T>>};
 
 #[doc = "Create a smallintmap"]
 fn mk<T: copy>() -> smallintmap<T> {
-    let v: [mut option<T>] = [mut];
-    ret @{mut v: v};
+    ret @{v: dvec()};
 }
 
 #[doc = "
 Add a value to the map. If the map already contains a value for
 the specified key then the original value is replaced.
 "]
-fn insert<T: copy>(m: smallintmap<T>, key: uint, val: T) {
-    vec::grow_set::<option<T>>(m.v, key, none::<T>, some::<T>(val));
+fn insert<T: copy>(self: smallintmap<T>, key: uint, val: T) {
+    self.v.grow_set_elt(key, none, some(val));
 }
 
 #[doc = "
 Get the value for the specified key. If the key does not exist
 in the map then returns none
 "]
-fn find<T: copy>(m: smallintmap<T>, key: uint) -> option<T> {
-    if key < vec::len::<option<T>>(m.v) { ret m.v[key]; }
+fn find<T: copy>(self: smallintmap<T>, key: uint) -> option<T> {
+    if key < self.v.len() { ret self.v.get_elt(key); }
     ret none::<T>;
 }
 
@@ -39,8 +39,8 @@ Get the value for the specified key
 
 If the key does not exist in the map
 "]
-fn get<T: copy>(m: smallintmap<T>, key: uint) -> T {
-    alt find(m, key) {
+fn get<T: copy>(self: smallintmap<T>, key: uint) -> T {
+    alt find(self, key) {
       none { #error("smallintmap::get(): key not present"); fail; }
       some(v) { ret v; }
     }
@@ -49,25 +49,15 @@ fn get<T: copy>(m: smallintmap<T>, key: uint) -> T {
 #[doc = "
 Returns true if the map contains a value for the specified key
 "]
-fn contains_key<T: copy>(m: smallintmap<T>, key: uint) -> bool {
-    ret !option::is_none(find::<T>(m, key));
-}
-
-// FIXME: Are these really useful?
-
-fn truncate<T: copy>(m: smallintmap<T>, len: uint) {
-    m.v = vec::to_mut(vec::slice::<option<T>>(m.v, 0u, len));
-}
-
-fn max_key<T: copy>(m: smallintmap<T>) -> uint {
-    ret vec::len::<option<T>>(m.v);
+fn contains_key<T: copy>(self: smallintmap<T>, key: uint) -> bool {
+    ret !option::is_none(find(self, key));
 }
 
 #[doc = "Implements the map::map interface for smallintmap"]
 impl <V: copy> of map::map<uint, V> for smallintmap<V> {
     fn size() -> uint {
         let mut sz = 0u;
-        for vec::each(self.v) {|item|
+        for self.v.each {|item|
             alt item { some(_) { sz += 1u; } _ {} }
         }
         sz
@@ -78,9 +68,9 @@ impl <V: copy> of map::map<uint, V> for smallintmap<V> {
         ret !exists;
     }
     fn remove(&&key: uint) -> option<V> {
-        if key >= vec::len(self.v) { ret none; }
-        let old = self.v[key];
-        self.v[key] = none;
+        if key >= self.v.len() { ret none; }
+        let old = self.v.get_elt(key);
+        self.v.set_elt(key, none);
         old
     }
     fn contains_key(&&key: uint) -> bool {
@@ -92,9 +82,9 @@ impl <V: copy> of map::map<uint, V> for smallintmap<V> {
     fn each(it: fn(&&uint, V) -> bool) {
         let mut idx = 0u, l = self.v.len();
         while idx < l {
-            alt self.v[idx] {
+            alt self.v.get_elt(idx) {
               some(elt) {
-                if !it(idx, copy elt) { break; }
+                if !it(idx, elt) { break; }
               }
               none { }
             }
@@ -104,7 +94,7 @@ impl <V: copy> of map::map<uint, V> for smallintmap<V> {
     fn each_key(it: fn(&&uint) -> bool) {
         let mut idx = 0u, l = self.v.len();
         while idx < l {
-            if self.v[idx] != none && !it(idx) { ret; }
+            if self.v.get_elt(idx) != none && !it(idx) { ret; }
             idx += 1u;
         }
     }
diff --git a/src/test/bench/vec-append.rs b/src/test/bench/vec-append.rs
index a84c776f0cc6..8c5e5195cbc1 100644
--- a/src/test/bench/vec-append.rs
+++ b/src/test/bench/vec-append.rs
@@ -24,11 +24,17 @@ fn main(args: [str]) {
     let args = if vec::len(args) <= 1u {["", "100000"]} else {args};
     let max = uint::from_str(args[1]).get();
     let start = std::time::precise_time_s();
-    collect_raw(max);
+    let raw_v = collect_raw(max);
     let mid = std::time::precise_time_s();
-    collect_dvec(max);
+    let dvec_v = collect_dvec(max);
     let end = std::time::precise_time_s();
 
+    // check each vector
+    assert raw_v.len() == max;
+    for raw_v.eachi { |i, v| assert i == v; }
+    assert dvec_v.len() == max;
+    for dvec_v.eachi { |i, v| assert i == v; }
+
     let raw = mid - start;
     let dvec = end - mid;