Unbox almost all the closures

src/libarena/lib.rs

@@ -28,6 +28,7 @@
        html_root_url = "http://doc.rust-lang.org/nightly/")]
 
 #![feature(unsafe_destructor)]
+#![feature(unboxed_closures)]
 #![allow(missing_docs)]
 
 extern crate alloc;
@@ -209,7 +210,7 @@ impl Arena {
     }
 
     #[inline]
-    fn alloc_copy<T>(&self, op: || -> T) -> &mut T {
+    fn alloc_copy<T, F>(&self, op: F) -> &mut T where F: FnOnce() -> T {
         unsafe {
             let ptr = self.alloc_copy_inner(mem::size_of::<T>(),
                                             mem::min_align_of::<T>());
@@ -263,7 +264,7 @@ impl Arena {
     }
 
     #[inline]
-    fn alloc_noncopy<T>(&self, op: || -> T) -> &mut T {
+    fn alloc_noncopy<T, F>(&self, op: F) -> &mut T where F: FnOnce() -> T {
         unsafe {
             let tydesc = get_tydesc::<T>();
             let (ty_ptr, ptr) =
@@ -287,7 +288,7 @@ impl Arena {
     /// Allocates a new item in the arena, using `op` to initialize the value,
     /// and returns a reference to it.
     #[inline]
-    pub fn alloc<T>(&self, op: || -> T) -> &mut T {
+    pub fn alloc<T, F>(&self, op: F) -> &mut T where F: FnOnce() -> T {
         unsafe {
             if intrinsics::needs_drop::<T>() {
                 self.alloc_noncopy(op)
@@ -339,7 +340,7 @@ fn test_arena_destructors_fail() {
         arena.alloc(|| { [0u8, 1u8, 2u8] });
     }
     // Now, panic while allocating
-    arena.alloc::<Rc<int>>(|| {
+    arena.alloc::<Rc<int>, _>(|| {
         panic!();
     });
 }

src/libcollections/bench.rs

@@ -13,9 +13,14 @@ use std::rand;
 use std::rand::Rng;
 use test::Bencher;
 
-pub fn insert_rand_n<M>(n: uint, map: &mut M, b: &mut Bencher,
-                        insert: |&mut M, uint|,
-                        remove: |&mut M, uint|) {
+pub fn insert_rand_n<M, I, R>(n: uint,
+                              map: &mut M,
+                              b: &mut Bencher,
+                              mut insert: I,
+                              mut remove: R) where
+    I: FnMut(&mut M, uint),
+    R: FnMut(&mut M, uint),
+{
     // setup
     let mut rng = rand::weak_rng();
 
@@ -31,9 +36,14 @@ pub fn insert_rand_n<M>(n: uint, map: &mut M, b: &mut Bencher,
     })
 }
 
-pub fn insert_seq_n<M>(n: uint, map: &mut M, b: &mut Bencher,
-                       insert: |&mut M, uint|,
-                       remove: |&mut M, uint|) {
+pub fn insert_seq_n<M, I, R>(n: uint,
+                             map: &mut M,
+                             b: &mut Bencher,
+                             mut insert: I,
+                             mut remove: R) where
+    I: FnMut(&mut M, uint),
+    R: FnMut(&mut M, uint),
+{
     // setup
     for i in range(0u, n) {
         insert(map, i * 2);
@@ -48,9 +58,14 @@ pub fn insert_seq_n<M>(n: uint, map: &mut M, b: &mut Bencher,
     })
 }
 
-pub fn find_rand_n<M, T>(n: uint, map: &mut M, b: &mut Bencher,
-                         insert: |&mut M, uint|,
-                         find: |&M, uint| -> T) {
+pub fn find_rand_n<M, T, I, F>(n: uint,
+                               map: &mut M,
+                               b: &mut Bencher,
+                               mut insert: I,
+                               mut find: F) where
+    I: FnMut(&mut M, uint),
+    F: FnMut(&M, uint) -> T,
+{
     // setup
     let mut rng = rand::weak_rng();
     let mut keys = Vec::from_fn(n, |_| rng.gen::<uint>() % n);
@@ -70,9 +85,14 @@ pub fn find_rand_n<M, T>(n: uint, map: &mut M, b: &mut Bencher,
     })
 }
 
-pub fn find_seq_n<M, T>(n: uint, map: &mut M, b: &mut Bencher,
-                        insert: |&mut M, uint|,
-                        find: |&M, uint| -> T) {
+pub fn find_seq_n<M, T, I, F>(n: uint,
+                              map: &mut M,
+                              b: &mut Bencher,
+                              mut insert: I,
+                              mut find: F) where
+    I: FnMut(&mut M, uint),
+    F: FnMut(&M, uint) -> T,
+{
     // setup
     for i in range(0u, n) {
         insert(map, i);

src/libcollections/bit.rs

@@ -174,7 +174,7 @@ impl<'a> Iterator<(uint, u32)> for MaskWords<'a> {
 
 impl Bitv {
     #[inline]
-    fn process(&mut self, other: &Bitv, op: |u32, u32| -> u32) -> bool {
+    fn process<F>(&mut self, other: &Bitv, mut op: F) -> bool where F: FnMut(u32, u32) -> u32 {
         let len = other.storage.len();
         assert_eq!(self.storage.len(), len);
         let mut changed = false;
@@ -816,7 +816,7 @@ pub fn from_bytes(bytes: &[u8]) -> Bitv {
 /// let bv = from_fn(5, |i| { i % 2 == 0 });
 /// assert!(bv.eq_vec(&[true, false, true, false, true]));
 /// ```
-pub fn from_fn(len: uint, f: |index: uint| -> bool) -> Bitv {
+pub fn from_fn<F>(len: uint, mut f: F) -> Bitv where F: FnMut(uint) -> bool {
     let mut bitv = Bitv::with_capacity(len, false);
     for i in range(0u, len) {
         bitv.set(i, f(i));
@@ -1182,7 +1182,7 @@ impl BitvSet {
     }
 
     #[inline]
-    fn other_op(&mut self, other: &BitvSet, f: |u32, u32| -> u32) {
+    fn other_op<F>(&mut self, other: &BitvSet, mut f: F) where F: FnMut(u32, u32) -> u32 {
         // Expand the vector if necessary
         self.reserve(other.capacity());
 
@@ -1277,10 +1277,12 @@ impl BitvSet {
     #[inline]
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn union<'a>(&'a self, other: &'a BitvSet) -> TwoBitPositions<'a> {
+        fn or(w1: u32, w2: u32) -> u32 { w1 | w2 }
+
         TwoBitPositions {
             set: self,
             other: other,
-            merge: |w1, w2| w1 | w2,
+            merge: or,
             current_word: 0u32,
             next_idx: 0u
         }
@@ -1306,11 +1308,13 @@ impl BitvSet {
     #[inline]
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn intersection<'a>(&'a self, other: &'a BitvSet) -> Take<TwoBitPositions<'a>> {
+        fn bitand(w1: u32, w2: u32) -> u32 { w1 & w2 }
+
         let min = cmp::min(self.capacity(), other.capacity());
         TwoBitPositions {
             set: self,
             other: other,
-            merge: |w1, w2| w1 & w2,
+            merge: bitand,
             current_word: 0u32,
             next_idx: 0
         }.take(min)
@@ -1343,10 +1347,12 @@ impl BitvSet {
     #[inline]
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn difference<'a>(&'a self, other: &'a BitvSet) -> TwoBitPositions<'a> {
+        fn diff(w1: u32, w2: u32) -> u32 { w1 & !w2 }
+
         TwoBitPositions {
             set: self,
             other: other,
-            merge: |w1, w2| w1 & !w2,
+            merge: diff,
             current_word: 0u32,
             next_idx: 0
         }
@@ -1373,10 +1379,12 @@ impl BitvSet {
     #[inline]
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn symmetric_difference<'a>(&'a self, other: &'a BitvSet) -> TwoBitPositions<'a> {
+        fn bitxor(w1: u32, w2: u32) -> u32 { w1 ^ w2 }
+
         TwoBitPositions {
             set: self,
             other: other,
-            merge: |w1, w2| w1 ^ w2,
+            merge: bitxor,
             current_word: 0u32,
             next_idx: 0
         }
@@ -1614,7 +1622,7 @@ pub struct BitPositions<'a> {
 pub struct TwoBitPositions<'a> {
     set: &'a BitvSet,
     other: &'a BitvSet,
-    merge: |u32, u32|: 'a -> u32,
+    merge: fn(u32, u32) -> u32,
     current_word: u32,
     next_idx: uint
 }

src/libcollections/btree/map.rs

@@ -107,10 +107,12 @@ pub struct MoveEntries<K, V> {
 }
 
 /// An iterator over a BTreeMap's keys.
-pub type Keys<'a, K, V> = iter::Map<'static, (&'a K, &'a V), &'a K, Entries<'a, K, V>>;
+pub type Keys<'a, K, V> =
+    iter::Map<(&'a K, &'a V), &'a K, Entries<'a, K, V>, fn((&'a K, &'a V)) -> &'a K>;
 
 /// An iterator over a BTreeMap's values.
-pub type Values<'a, K, V> = iter::Map<'static, (&'a K, &'a V), &'a V, Entries<'a, K, V>>;
+pub type Values<'a, K, V> =
+    iter::Map<(&'a K, &'a V), &'a V, Entries<'a, K, V>, fn((&'a K, &'a V)) -> &'a V>;
 
 /// A view into a single entry in a map, which may either be vacant or occupied.
 pub enum Entry<'a, K:'a, V:'a> {
@@ -1207,7 +1209,9 @@ impl<K, V> BTreeMap<K, V> {
     /// ```
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn keys<'a>(&'a self) -> Keys<'a, K, V> {
-        self.iter().map(|(k, _)| k)
+        fn first<A, B>((a, _): (A, B)) -> A { a }
+
+        self.iter().map(first)
     }
 
     /// Gets an iterator over the values of the map.
@@ -1226,7 +1230,9 @@ impl<K, V> BTreeMap<K, V> {
     /// ```
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn values<'a>(&'a self) -> Values<'a, K, V> {
-        self.iter().map(|(_, v)| v)
+        fn second<A, B>((_, b): (A, B)) -> B { b }
+
+        self.iter().map(second)
     }
 
     /// Return the number of elements in the map.

src/libcollections/btree/set.rs

@@ -36,7 +36,8 @@ pub struct BTreeSet<T>{
 pub type Items<'a, T> = Keys<'a, T, ()>;
 
 /// An owning iterator over a BTreeSet's items.
-pub type MoveItems<T> = iter::Map<'static, (T, ()), T, MoveEntries<T, ()>>;
+pub type MoveItems<T> =
+    iter::Map<(T, ()), T, MoveEntries<T, ()>, fn((T, ())) -> T>;
 
 /// A lazy iterator producing elements in the set difference (in-order).
 pub struct DifferenceItems<'a, T:'a> {
@@ -87,7 +88,9 @@ impl<T> BTreeSet<T> {
     /// Gets an iterator for moving out the BtreeSet's contents.
     #[unstable = "matches collection reform specification, waiting for dust to settle"]
     pub fn into_iter(self) -> MoveItems<T> {
-        self.map.into_iter().map(|(k, _)| k)
+        fn first<A, B>((a, _): (A, B)) -> A { a }
+
+        self.map.into_iter().map(first)
     }
 }
 
@@ -600,22 +603,31 @@ mod test {
       assert!(hash::hash(&x) == hash::hash(&y));
     }
 
-    fn check(a: &[int],
-             b: &[int],
-             expected: &[int],
-             f: |&BTreeSet<int>, &BTreeSet<int>, f: |&int| -> bool| -> bool) {
+    struct Counter<'a, 'b> {
+        i: &'a mut uint,
+        expected: &'b [int],
+    }
+
+    impl<'a, 'b> FnMut(&int) -> bool for Counter<'a, 'b> {
+        extern "rust-call" fn call_mut(&mut self, (&x,): (&int,)) -> bool {
+            assert_eq!(x, self.expected[*self.i]);
+            *self.i += 1;
+            true
+        }
+    }
+
+    fn check<F>(a: &[int], b: &[int], expected: &[int], f: F) where
+        // FIXME Replace Counter with `Box<FnMut(_) -> _>`
+        F: FnOnce(&BTreeSet<int>, &BTreeSet<int>, Counter) -> bool,
+    {
         let mut set_a = BTreeSet::new();
         let mut set_b = BTreeSet::new();
 
         for x in a.iter() { assert!(set_a.insert(*x)) }
         for y in b.iter() { assert!(set_b.insert(*y)) }
 
         let mut i = 0;
-        f(&set_a, &set_b, |x| {
-            assert_eq!(*x, expected[i]);
-            i += 1;
-            true
-        });
+        f(&set_a, &set_b, Counter { i: &mut i, expected: expected });
         assert_eq!(i, expected.len());
     }
 

src/libcollections/dlist.rs

@@ -351,18 +351,16 @@ impl<T> DList<T> {
     ///     println!("{}", e); // prints 2, then 4, then 11, then 7, then 8
     /// }
     /// ```
-    pub fn insert_when(&mut self, elt: T, f: |&T, &T| -> bool) {
-        {
-            let mut it = self.iter_mut();
-            loop {
-                match it.peek_next() {
-                    None => break,
-                    Some(x) => if f(x, &elt) { break }
-                }
-                it.next();
+    pub fn insert_when<F>(&mut self, elt: T, mut f: F) where F: FnMut(&T, &T) -> bool {
+        let mut it = self.iter_mut();
+        loop {
+            match it.peek_next() {
+                None => break,
+                Some(x) => if f(x, &elt) { break }
             }
-            it.insert_next(elt);
+            it.next();
         }
+        it.insert_next(elt);
     }
 
     /// Merges `other` into this `DList`, using the function `f`.
@@ -371,7 +369,7 @@ impl<T> DList<T> {
     /// put `a` in the result if `f(a, b)` is true, and otherwise `b`.
     ///
     /// This operation should compute in O(max(N, M)) time.
-    pub fn merge(&mut self, mut other: DList<T>, f: |&T, &T| -> bool) {
+    pub fn merge<F>(&mut self, mut other: DList<T>, mut f: F) where F: FnMut(&T, &T) -> bool {
         {
             let mut it = self.iter_mut();
             loop {