---

yaml
---
r: 139265
b: refs/heads/try2
c: d774333
h: refs/heads/master
i:
  139263: 8878be9
v: v3

Author: thestinger

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 794814945674d27a4fb68aedcea86c39dd5ccd4e
+refs/heads/try2: d77433386be3d5afa201cfd40dbaaa4d20dbbd80
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/libcore/hashmap.rs

@@ -24,6 +24,7 @@ pub mod linear {
     use rand;
     use uint;
     use vec;
+    use util::unreachable;
 
     static INITIAL_CAPACITY: uint = 32u; // 2^5
 
@@ -192,6 +193,14 @@ pub mod linear {
             }
         }
 
+        #[inline(always)]
+        fn mut_value_for_bucket(&mut self, idx: uint) -> &'self mut V {
+            match self.buckets[idx] {
+                Some(ref mut bkt) => &mut bkt.value,
+                None => unreachable()
+            }
+        }
+
         /// Inserts the key value pair into the buckets.
         /// Assumes that there will be a bucket.
         /// True if there was no previous entry with that key
@@ -338,7 +347,7 @@ pub mod linear {
             }
         }
 
-        /// Return the value corresponding to the key in the map
+        /// Return a reference to the value corresponding to the key
         fn find(&self, k: &K) -> Option<&'self V> {
             match self.bucket_for_key(k) {
                 FoundEntry(idx) => Some(self.value_for_bucket(idx)),
@@ -410,6 +419,17 @@ pub mod linear {
             old_value
         }
 
+        /// Return a mutable reference to the value corresponding to the key
+        fn find_mut(&mut self, k: &K) -> Option<&'self mut V> {
+            let idx = match self.bucket_for_key(k) {
+                FoundEntry(idx) => idx,
+                TableFull | FoundHole(_) => return None
+            };
+            unsafe {  // FIXME(#4903)---requires flow-sensitive borrow checker
+                Some(::cast::transmute_mut_region(self.mut_value_for_bucket(idx)))
+            }
+        }
+
         /// Return the value corresponding to the key in the map, or insert
         /// and return the value if it doesn't exist.
         fn find_or_insert(&mut self, k: K, v: V) -> &'self V {
@@ -655,6 +675,19 @@ pub mod linear {
             fail_unless!(*m.get(&2) == 4);
         }
 
+        #[test]
+        fn test_find_mut() {
+            let mut m = LinearMap::new();
+            fail_unless!(m.insert(1, 12));
+            fail_unless!(m.insert(2, 8));
+            fail_unless!(m.insert(5, 14));
+            let new = 100;
+            match m.find_mut(&5) {
+                None => fail!(), Some(x) => *x = new
+            }
+            assert_eq!(m.find(&5), Some(&new));
+        }
+
         #[test]
         pub fn test_insert_overwrite() {
             let mut m = LinearMap::new();