---

yaml
---
r: 277303
b: refs/heads/try
c: 241a3e4
h: refs/heads/master
i:
  277301: 7bea81b
  277299: 32695fc
  277295: 4a36d94

Author: jooert

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 6dbb0e86aec11050480beb76eade6fb805010ba7
 refs/heads/snap-stage3: 235d77457d80b549dad3ac36d94f235208a1eafb
-refs/heads/try: af000a7bbffcaf5e75ff97b245fa5a413062acc1
+refs/heads/try: 241a3e4689d3004daf9e1d36cec2235cbd301fbf
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try/configure

@@ -609,7 +609,6 @@ opt llvm-version-check 1 "check if the LLVM version is supported, build anyway"
 opt rustbuild 0 "use the rust and cargo based build system"
 opt orbit 0 "get MIR where it belongs - everywhere; most importantly, in orbit"
 opt codegen-tests 1 "run the src/test/codegen tests"
-opt option-checking 1 "complain about unrecognized options in this configure script"
 
 # Optimization and debugging options. These may be overridden by the release channel, etc.
 opt_nosave optimize 1 "build optimized rust code"
@@ -675,11 +674,8 @@ then
 fi
 
 # Validate Options
-if [ -z "$CFG_DISABLE_OPTION_CHECKING" ]
-then
-    step_msg "validating $CFG_SELF args"
-    validate_opt
-fi
+step_msg "validating $CFG_SELF args"
+validate_opt
 
 # Validate the release channel, and configure options
 case "$CFG_RELEASE_CHANNEL" in

branches/try/src/libcollections/btree/map.rs

@@ -11,7 +11,7 @@
 use core::cmp::Ordering;
 use core::fmt::Debug;
 use core::hash::{Hash, Hasher};
-use core::iter::FromIterator;
+use core::iter::{FromIterator, Peekable};
 use core::marker::PhantomData;
 use core::ops::Index;
 use core::{fmt, intrinsics, mem, ptr};
@@ -348,6 +348,12 @@ pub struct OccupiedEntry<'a, K: 'a, V: 'a> {
     _marker: PhantomData<&'a mut (K, V)>,
 }
 
+// An iterator for merging two sorted sequences into one
+struct MergeIter<K, V, I: Iterator<Item=(K, V)>> {
+    left: Peekable<I>,
+    right: Peekable<I>,
+}
+
 impl<K: Ord, V> BTreeMap<K, V> {
     /// Makes a new empty BTreeMap with a reasonable choice for B.
     ///
@@ -535,6 +541,62 @@ impl<K: Ord, V> BTreeMap<K, V> {
         }
     }
 
+    /// Moves all elements from `other` into `Self`, leaving `other` empty.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(btree_append)]
+    /// use std::collections::BTreeMap;
+    ///
+    /// let mut a = BTreeMap::new();
+    /// a.insert(1, "a");
+    /// a.insert(2, "b");
+    /// a.insert(3, "c");
+    ///
+    /// let mut b = BTreeMap::new();
+    /// b.insert(3, "d");
+    /// b.insert(4, "e");
+    /// b.insert(5, "f");
+    ///
+    /// a.append(&mut b);
+    ///
+    /// assert_eq!(a.len(), 5);
+    /// assert_eq!(b.len(), 0);
+    ///
+    /// assert_eq!(a[&1], "a");
+    /// assert_eq!(a[&2], "b");
+    /// assert_eq!(a[&3], "d");
+    /// assert_eq!(a[&4], "e");
+    /// assert_eq!(a[&5], "f");
+    /// ```
+    #[unstable(feature = "btree_append", reason = "recently added as part of collections reform 2",
+               issue = "19986")]
+    pub fn append(&mut self, other: &mut Self) {
+        // Do we have to append anything at all?
+        if other.len() == 0 {
+            return;
+        }
+
+        // We can just swap `self` and `other` if `self` is empty.
+        if self.len() == 0 {
+            mem::swap(self, other);
+            return;
+        }
+
+        // First, we merge `self` and `other` into a sorted sequence in linear time.
+        let self_iter = mem::replace(self, BTreeMap::new()).into_iter();
+        let other_iter = mem::replace(other, BTreeMap::new()).into_iter();
+        let iter = MergeIter {
+            left: self_iter.peekable(),
+            right: other_iter.peekable(),
+        };
+
+        // Second, we build a tree from the sorted sequence in linear time.
+        self.from_sorted_iter(iter);
+        self.fix_right_edge();
+    }
+
     /// Constructs a double-ended iterator over a sub-range of elements in the map, starting
     /// at min, and ending at max. If min is `Unbounded`, then it will be treated as "negative
     /// infinity", and if max is `Unbounded`, then it will be treated as "positive infinity".
@@ -724,6 +786,76 @@ impl<K: Ord, V> BTreeMap<K, V> {
             })
         }
     }
+
+    fn from_sorted_iter<I: Iterator<Item=(K, V)>>(&mut self, iter: I) {
+        let mut cur_node = last_leaf_edge(self.root.as_mut()).into_node();
+        // Iterate through all key-value pairs, pushing them into nodes at the right level.
+        for (key, value) in iter {
+            // Try to push key-value pair into the current leaf node.
+            if cur_node.len() < node::CAPACITY {
+                cur_node.push(key, value);
+            } else {
+                // No space left, go up and push there.
+                let mut open_node;
+                let mut test_node = cur_node.forget_type();
+                loop {
+                    match test_node.ascend() {
+                        Ok(parent) => {
+                            let parent = parent.into_node();
+                            if parent.len() < node::CAPACITY {
+                                // Found a node with space left, push here.
+                                open_node = parent;
+                                break;
+                            } else {
+                                // Go up again.
+                                test_node = parent.forget_type();
+                            }
+                        },
+                        Err(node) => {
+                            // We are at the top, create a new root node and push there.
+                            open_node = node.into_root_mut().push_level();
+                            break;
+                        },
+                    }
+                }
+
+                // Push key-value pair and new right subtree.
+                let tree_height = open_node.height() - 1;
+                let mut right_tree = node::Root::new_leaf();
+                for _ in 0..tree_height {
+                    right_tree.push_level();
+                }
+                open_node.push(key, value, right_tree);
+
+                // Go down to the right-most leaf again.
+                cur_node = last_leaf_edge(open_node.forget_type()).into_node();
+            }
+
+            self.length += 1;
+        }
+    }
+
+    fn fix_right_edge(&mut self) {
+        // Handle underfull nodes, start from the top.
+        let mut cur_node = self.root.as_mut();
+        while let Internal(internal) = cur_node.force() {
+            // Check if right-most child is underfull.
+            let mut last_edge = internal.last_edge();
+            let right_child_len = last_edge.reborrow().descend().len();
+            if right_child_len < node::CAPACITY / 2 {
+                // We need to steal.
+                let mut last_kv = match last_edge.left_kv() {
+                    Ok(left) => left,
+                    Err(_) => unreachable!(),
+                };
+                last_kv.bulk_steal_left(node::CAPACITY/2 - right_child_len);
+                last_edge = last_kv.right_edge();
+            }
+
+            // Go further down.
+            cur_node = last_edge.descend();
+        }
+    }
 }
 
 impl<'a, K: 'a, V: 'a> IntoIterator for &'a BTreeMap<K, V> {
@@ -1690,32 +1822,41 @@ fn handle_underfull_node<'a, K, V>(node: NodeRef<marker::Mut<'a>,
     };
 
     if handle.can_merge() {
-        return Merged(handle.merge().into_node());
+        Merged(handle.merge().into_node())
     } else {
-        unsafe {
-            let (k, v, edge) = if is_left {
-                handle.reborrow_mut().left_edge().descend().pop()
-            } else {
-                handle.reborrow_mut().right_edge().descend().pop_front()
-            };
+        if is_left {
+            handle.steal_left();
+        } else {
+            handle.steal_right();
+        }
+        Stole(handle.into_node())
+    }
+}
 
-            let k = mem::replace(handle.reborrow_mut().into_kv_mut().0, k);
-            let v = mem::replace(handle.reborrow_mut().into_kv_mut().1, v);
+impl<K: Ord, V, I: Iterator<Item=(K, V)>> Iterator for MergeIter<K, V, I> {
+    type Item = (K, V);
 
-            // FIXME: reuse cur_node?
-            if is_left {
-                match handle.reborrow_mut().right_edge().descend().force() {
-                    Leaf(mut leaf) => leaf.push_front(k, v),
-                    Internal(mut internal) => internal.push_front(k, v, edge.unwrap())
-                }
-            } else {
-                match handle.reborrow_mut().left_edge().descend().force() {
-                    Leaf(mut leaf) => leaf.push(k, v),
-                    Internal(mut internal) => internal.push(k, v, edge.unwrap())
-                }
-            }
-        }
+    fn next(&mut self) -> Option<(K, V)> {
+        let res = match (self.left.peek(), self.right.peek()) {
+            (Some(&(ref left_key, _)), Some(&(ref right_key, _))) => left_key.cmp(right_key),
+            (Some(_), None) => Ordering::Less,
+            (None, Some(_)) => Ordering::Greater,
+            (None, None) => return None,
+        };
 
-        return Stole(handle.into_node());
+        // Check which elements comes first and only advance the corresponding iterator.
+        // If two keys are equal, take the value from `right`.
+        match res {
+            Ordering::Less => {
+                self.left.next()
+            },
+            Ordering::Greater => {
+                self.right.next()
+            },
+            Ordering::Equal => {
+                self.left.next();
+                self.right.next()
+            },
+        }
     }
 }