1 //===--- ImmutableSet.h - Immutable (functional) set interface --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Ted Kremenek and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the ImutAVLTree and ImmutableSet classes.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_ADT_IMSET_H
15 #define LLVM_ADT_IMSET_H
17 #include "llvm/Support/Allocator.h"
18 #include "llvm/ADT/FoldingSet.h"
23 //===----------------------------------------------------------------------===//
24 // Immutable AVL-Tree Definition.
25 //===----------------------------------------------------------------------===//
27 template <typename ImutInfo> class ImutAVLFactory;
29 template <typename ImutInfo> class ImutAVLTreeInOrderIterator;
31 template <typename ImutInfo >
32 class ImutAVLTree : public FoldingSetNode {
34 typedef typename ImutInfo::key_type_ref key_type_ref;
35 typedef typename ImutInfo::value_type value_type;
36 typedef typename ImutInfo::value_type_ref value_type_ref;
38 typedef ImutAVLFactory<ImutInfo> Factory;
39 friend class ImutAVLFactory<ImutInfo>;
41 typedef ImutAVLTreeInOrderIterator<ImutInfo> iterator;
43 //===----------------------------------------------------===//
45 //===----------------------------------------------------===//
47 /// getLeft - Returns a pointer to the left subtree. This value
48 /// is NULL if there is no left subtree.
49 ImutAVLTree* getLeft() const {
50 assert (!isMutable() && "Node is incorrectly marked mutable.");
52 return reinterpret_cast<ImutAVLTree*>(Left);
55 /// getRight - Returns a pointer to the right subtree. This value is
56 /// NULL if there is no right subtree.
57 ImutAVLTree* getRight() const { return Right; }
60 /// getHeight - Returns the height of the tree. A tree with no subtrees
61 /// has a height of 1.
62 unsigned getHeight() const { return Height; }
64 /// getValue - Returns the data value associated with the tree node.
65 const value_type& getValue() const { return Value; }
67 /// find - Finds the subtree associated with the specified key value.
68 /// This method returns NULL if no matching subtree is found.
69 ImutAVLTree* find(key_type_ref K) {
70 ImutAVLTree *T = this;
73 key_type_ref CurrentKey = ImutInfo::KeyOfValue(T->getValue());
75 if (ImutInfo::isEqual(K,CurrentKey))
77 else if (ImutInfo::isLess(K,CurrentKey))
86 /// size - Returns the number of nodes in the tree, which includes
87 /// both leaves and non-leaf nodes.
88 unsigned size() const {
91 if (const ImutAVLTree* L = getLeft()) n += L->size();
92 if (const ImutAVLTree* R = getRight()) n += R->size();
97 /// begin - Returns an iterator that iterates over the nodes of the tree
98 /// in an inorder traversal. The returned iterator thus refers to the
99 /// the tree node with the minimum data element.
100 iterator begin() const { return iterator(this); }
102 /// end - Returns an iterator for the tree that denotes the end of an
103 /// inorder traversal.
104 iterator end() const { return iterator(); }
106 /// isEqual - Compares two trees for structural equality and returns true
107 /// if they are equal. This worst case performance of this operation is
108 // linear in the sizes of the trees.
109 bool isEqual(const ImutAVLTree& RHS) const {
113 iterator LItr = begin(), LEnd = end();
114 iterator RItr = RHS.begin(), REnd = RHS.end();
116 while (LItr != LEnd && RItr != REnd) {
117 if (*LItr == *RItr) {
123 // FIXME: need to compare data values, not key values, but our
124 // traits don't support this yet.
125 if (!ImutInfo::isEqual(ImutInfo::KeyOfValue(LItr->getValue()),
126 ImutInfo::KeyOfValue(RItr->getValue())))
133 return LItr == LEnd && RItr == REnd;
136 /// isNotEqual - Compares two trees for structural inequality. Performance
137 /// is the same is isEqual.
138 bool isNotEqual(const ImutAVLTree& RHS) const { return !isEqual(RHS); }
140 /// contains - Returns true if this tree contains a subtree (node) that
141 /// has an data element that matches the specified key. Complexity
142 /// is logarithmic in the size of the tree.
143 bool contains(const key_type_ref K) { return (bool) find(K); }
145 /// foreach - A member template the accepts invokes operator() on a functor
146 /// object (specifed by Callback) for every node/subtree in the tree.
147 /// Nodes are visited using an inorder traversal.
148 template <typename Callback>
149 void foreach(Callback& C) {
150 if (ImutAVLTree* L = getLeft()) L->foreach(C);
154 if (ImutAVLTree* R = getRight()) R->foreach(C);
157 /// verify - A utility method that checks that the balancing and
158 /// ordering invariants of the tree are satisifed. It is a recursive
159 /// method that returns the height of the tree, which is then consumed
160 /// by the enclosing verify call. External callers should ignore the
161 /// return value. An invalid tree will cause an assertion to fire in
163 unsigned verify() const {
164 unsigned HL = getLeft() ? getLeft()->verify() : 0;
165 unsigned HR = getRight() ? getRight()->verify() : 0;
167 assert (getHeight() == ( HL > HR ? HL : HR ) + 1
168 && "Height calculation wrong.");
170 assert ((HL > HR ? HL-HR : HR-HL) <= 2
171 && "Balancing invariant violated.");
175 || ImutInfo::isLess(ImutInfo::KeyOfValue(getLeft()->getValue()),
176 ImutInfo::KeyOfValue(getValue()))
177 && "Value in left child is not less that current value.");
181 || ImutInfo::isLess(ImutInfo::KeyOfValue(getValue()),
182 ImutInfo::KeyOfValue(getRight()->getValue()))
183 && "Current value is not less that value of right child.");
188 //===----------------------------------------------------===//
190 //===----------------------------------------------------===//
198 //===----------------------------------------------------===//
199 // Profiling or FoldingSet.
200 //===----------------------------------------------------===//
203 void Profile(FoldingSetNodeID& ID, ImutAVLTree* L, ImutAVLTree* R,
207 ImutInfo::Profile(ID,V);
212 void Profile(FoldingSetNodeID& ID) {
213 Profile(ID,getSafeLeft(),getRight(),getValue());
216 //===----------------------------------------------------===//
217 // Internal methods (node manipulation; used by Factory).
218 //===----------------------------------------------------===//
222 ImutAVLTree(ImutAVLTree* l, ImutAVLTree* r, value_type_ref v, unsigned height)
223 : Left(reinterpret_cast<uintptr_t>(l) | 0x1),
224 Right(r), Height(height), Value(v) {}
226 bool isMutable() const { return Left & 0x1; }
228 ImutAVLTree* getSafeLeft() const {
229 return reinterpret_cast<ImutAVLTree*>(Left & ~0x1);
232 // Mutating operations. A tree root can be manipulated as long as
233 // its reference has not "escaped" from internal methods of a
234 // factory object (see below). When a tree pointer is externally
235 // viewable by client code, the internal "mutable bit" is cleared
236 // to mark the tree immutable. Note that a tree that still has
237 // its mutable bit set may have children (subtrees) that are themselves
240 void RemoveMutableFlag() {
241 assert (Left & 0x1 && "Mutable flag already removed.");
245 void setLeft(ImutAVLTree* NewLeft) {
246 assert (isMutable());
247 Left = reinterpret_cast<uintptr_t>(NewLeft) | 0x1;
250 void setRight(ImutAVLTree* NewRight) {
251 assert (isMutable());
255 void setHeight(unsigned h) {
256 assert (isMutable());
261 //===----------------------------------------------------------------------===//
262 // Immutable AVL-Tree Factory class.
263 //===----------------------------------------------------------------------===//
265 template <typename ImutInfo >
266 class ImutAVLFactory {
267 typedef ImutAVLTree<ImutInfo> TreeTy;
268 typedef typename TreeTy::value_type_ref value_type_ref;
269 typedef typename TreeTy::key_type_ref key_type_ref;
271 typedef FoldingSet<TreeTy> CacheTy;
274 BumpPtrAllocator Allocator;
276 //===--------------------------------------------------===//
278 //===--------------------------------------------------===//
283 TreeTy* Add(TreeTy* T, value_type_ref V) {
284 T = Add_internal(V,T);
289 TreeTy* Remove(TreeTy* T, key_type_ref V) {
290 T = Remove_internal(V,T);
295 TreeTy* GetEmptyTree() const { return NULL; }
297 //===--------------------------------------------------===//
298 // A bunch of quick helper functions used for reasoning
299 // about the properties of trees and their children.
300 // These have succinct names so that the balancing code
301 // is as terse (and readable) as possible.
302 //===--------------------------------------------------===//
305 bool isEmpty(TreeTy* T) const { return !T; }
306 unsigned Height(TreeTy* T) const { return T ? T->getHeight() : 0; }
307 TreeTy* Left(TreeTy* T) const { return T->getSafeLeft(); }
308 TreeTy* Right(TreeTy* T) const { return T->getRight(); }
309 value_type_ref Value(TreeTy* T) const { return T->Value; }
311 unsigned IncrementHeight(TreeTy* L, TreeTy* R) const {
312 unsigned hl = Height(L);
313 unsigned hr = Height(R);
314 return ( hl > hr ? hl : hr ) + 1;
317 //===--------------------------------------------------===//
318 // "CreateNode" is used to generate new tree roots that link
319 // to other trees. The functon may also simply move links
320 // in an existing root if that root is still marked mutable.
321 // This is necessary because otherwise our balancing code
322 // would leak memory as it would create nodes that are
323 // then discarded later before the finished tree is
324 // returned to the caller.
325 //===--------------------------------------------------===//
327 TreeTy* CreateNode(TreeTy* L, value_type_ref V, TreeTy* R) {
329 TreeTy::Profile(ID,L,R,V);
332 if (TreeTy* T = Cache.FindNodeOrInsertPos(ID,InsertPos))
335 assert (InsertPos != NULL);
337 // FIXME: more intelligent calculation of alignment.
338 TreeTy* T = (TreeTy*) Allocator.Allocate(sizeof(*T),16);
339 new (T) TreeTy(L,R,V,IncrementHeight(L,R));
341 Cache.InsertNode(T,InsertPos);
345 TreeTy* CreateNode(TreeTy* L, TreeTy* OldTree, TreeTy* R) {
346 assert (!isEmpty(OldTree));
348 if (OldTree->isMutable()) {
350 OldTree->setRight(R);
351 OldTree->setHeight(IncrementHeight(L,R));
354 else return CreateNode(L, Value(OldTree), R);
357 /// Balance - Used by Add_internal and Remove_internal to
358 /// balance a newly created tree.
359 TreeTy* Balance(TreeTy* L, value_type_ref V, TreeTy* R) {
361 unsigned hl = Height(L);
362 unsigned hr = Height(R);
365 assert (!isEmpty(L) &&
366 "Left tree cannot be empty to have a height >= 2.");
368 TreeTy* LL = Left(L);
369 TreeTy* LR = Right(L);
371 if (Height(LL) >= Height(LR))
372 return CreateNode(LL, L, CreateNode(LR,V,R));
374 assert (!isEmpty(LR) &&
375 "LR cannot be empty because it has a height >= 1.");
377 TreeTy* LRL = Left(LR);
378 TreeTy* LRR = Right(LR);
380 return CreateNode(CreateNode(LL,L,LRL), LR, CreateNode(LRR,V,R));
382 else if (hr > hl + 2) {
383 assert (!isEmpty(R) &&
384 "Right tree cannot be empty to have a height >= 2.");
386 TreeTy* RL = Left(R);
387 TreeTy* RR = Right(R);
389 if (Height(RR) >= Height(RL))
390 return CreateNode(CreateNode(L,V,RL), R, RR);
392 assert (!isEmpty(RL) &&
393 "RL cannot be empty because it has a height >= 1.");
395 TreeTy* RLL = Left(RL);
396 TreeTy* RLR = Right(RL);
398 return CreateNode(CreateNode(L,V,RLL), RL, CreateNode(RLR,R,RR));
401 return CreateNode(L,V,R);
404 /// Add_internal - Creates a new tree that includes the specified
405 /// data and the data from the original tree. If the original tree
406 /// already contained the data item, the original tree is returned.
407 TreeTy* Add_internal(value_type_ref V, TreeTy* T) {
409 return CreateNode(T, V, T);
411 assert (!T->isMutable());
413 key_type_ref K = ImutInfo::KeyOfValue(V);
414 key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
416 if (ImutInfo::isEqual(K,KCurrent))
417 return CreateNode(Left(T), V, Right(T));
418 else if (ImutInfo::isLess(K,KCurrent))
419 return Balance(Add_internal(V,Left(T)), Value(T), Right(T));
421 return Balance(Left(T), Value(T), Add_internal(V,Right(T)));
424 /// Remove_interal - Creates a new tree that includes all the data
425 /// from the original tree except the specified data. If the
426 /// specified data did not exist in the original tree, the original
427 /// tree is returned.
428 TreeTy* Remove_internal(key_type_ref K, TreeTy* T) {
432 assert (!T->isMutable());
434 key_type_ref KCurrent = ImutInfo::KeyOfValue(Value(T));
436 if (ImutInfo::isEqual(K,KCurrent))
437 return CombineLeftRightTrees(Left(T),Right(T));
438 else if (ImutInfo::isLess(K,KCurrent))
439 return Balance(Remove_internal(K,Left(T)), Value(T), Right(T));
441 return Balance(Left(T), Value(T), Remove_internal(K,Right(T)));
444 TreeTy* CombineLeftRightTrees(TreeTy* L, TreeTy* R) {
445 if (isEmpty(L)) return R;
446 if (isEmpty(R)) return L;
449 TreeTy* NewRight = RemoveMinBinding(R,OldNode);
450 return Balance(L,Value(OldNode),NewRight);
453 TreeTy* RemoveMinBinding(TreeTy* T, TreeTy*& NodeRemoved) {
454 assert (!isEmpty(T));
456 if (isEmpty(Left(T))) {
461 return Balance(RemoveMinBinding(Left(T),NodeRemoved),Value(T),Right(T));
464 /// MarkImmutable - Clears the mutable bits of a root and all of its
466 void MarkImmutable(TreeTy* T) {
467 if (!T || !T->isMutable())
470 T->RemoveMutableFlag();
471 MarkImmutable(Left(T));
472 MarkImmutable(Right(T));
477 //===----------------------------------------------------------------------===//
478 // Immutable AVL-Tree Iterators.
479 //===----------------------------------------------------------------------===//
481 template <typename ImutInfo>
482 class ImutAVLTreeGenericIterator {
483 SmallVector<uintptr_t,20> stack;
485 enum VisitFlag { VisitedNone=0x0, VisitedLeft=0x1, VisitedRight=0x3,
488 typedef ImutAVLTree<ImutInfo> TreeTy;
489 typedef ImutAVLTreeGenericIterator<ImutInfo> _Self;
491 inline ImutAVLTreeGenericIterator() {}
492 inline ImutAVLTreeGenericIterator(const TreeTy* Root) {
493 if (Root) stack.push_back(reinterpret_cast<uintptr_t>(Root));
496 TreeTy* operator*() const {
497 assert (!stack.empty());
498 return reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
501 uintptr_t getVisitState() {
502 assert (!stack.empty());
503 return stack.back() & Flags;
507 bool AtEnd() const { return stack.empty(); }
509 bool AtBeginning() const {
510 return stack.size() == 1 && getVisitState() == VisitedNone;
513 void SkipToParent() {
514 assert (!stack.empty());
520 switch (getVisitState()) {
522 stack.back() |= VisitedLeft;
525 stack.back() |= VisitedRight;
528 assert (false && "Unreachable.");
532 inline bool operator==(const _Self& x) const {
533 if (stack.size() != x.stack.size())
536 for (unsigned i = 0 ; i < stack.size(); i++)
537 if (stack[i] != x.stack[i])
543 inline bool operator!=(const _Self& x) const { return !operator==(x); }
545 _Self& operator++() {
546 assert (!stack.empty());
548 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
551 switch (getVisitState()) {
553 if (TreeTy* L = Current->getLeft())
554 stack.push_back(reinterpret_cast<uintptr_t>(L));
556 stack.back() |= VisitedLeft;
561 if (TreeTy* R = Current->getRight())
562 stack.push_back(reinterpret_cast<uintptr_t>(R));
564 stack.back() |= VisitedRight;
573 assert (false && "Unreachable.");
579 _Self& operator--() {
580 assert (!stack.empty());
582 TreeTy* Current = reinterpret_cast<TreeTy*>(stack.back() & ~Flags);
585 switch (getVisitState()) {
591 stack.back() &= ~Flags; // Set state to "VisitedNone."
593 if (TreeTy* L = Current->getLeft())
594 stack.push_back(reinterpret_cast<uintptr_t>(L) | VisitedRight);
599 stack.back() &= ~Flags;
600 stack.back() |= VisitedLeft;
602 if (TreeTy* R = Current->getRight())
603 stack.push_back(reinterpret_cast<uintptr_t>(R) | VisitedRight);
608 assert (false && "Unreachable.");
615 template <typename ImutInfo>
616 class ImutAVLTreeInOrderIterator {
617 typedef ImutAVLTreeGenericIterator<ImutInfo> InternalIteratorTy;
618 InternalIteratorTy InternalItr;
621 typedef ImutAVLTree<ImutInfo> TreeTy;
622 typedef ImutAVLTreeInOrderIterator<ImutInfo> _Self;
624 ImutAVLTreeInOrderIterator(const TreeTy* Root) : InternalItr(Root) {
625 if (Root) operator++(); // Advance to first element.
628 ImutAVLTreeInOrderIterator() : InternalItr() {}
630 inline bool operator==(const _Self& x) const {
631 return InternalItr == x.InternalItr;
634 inline bool operator!=(const _Self& x) const { return !operator==(x); }
636 inline TreeTy* operator*() { return *InternalItr; }
637 inline TreeTy* operator->() { return *InternalItr; }
639 inline _Self& operator++() {
641 while (!InternalItr.AtEnd() &&
642 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
647 inline _Self& operator--() {
649 while (!InternalItr.AtBeginning() &&
650 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft);
655 inline void SkipSubTree() {
656 InternalItr.SkipToParent();
658 while (!InternalItr.AtEnd() &&
659 InternalItr.getVisitState() != InternalIteratorTy::VisitedLeft)
664 //===----------------------------------------------------------------------===//
665 // Trait classes for Profile information.
666 //===----------------------------------------------------------------------===//
668 /// Generic profile template. The default behavior is to invoke the
669 /// profile method of an object. Specializations for primitive integers
670 /// and generic handling of pointers is done below.
671 template <typename T>
672 struct ImutProfileInfo {
673 typedef const T value_type;
674 typedef const T& value_type_ref;
676 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
681 /// Profile traits for integers.
682 template <typename T>
683 struct ImutProfileInteger {
684 typedef const T value_type;
685 typedef const T& value_type_ref;
687 static inline void Profile(FoldingSetNodeID& ID, value_type_ref X) {
692 #define PROFILE_INTEGER_INFO(X)\
693 template<> struct ImutProfileInfo<X> : ImutProfileInteger<X> {};
695 PROFILE_INTEGER_INFO(char)
696 PROFILE_INTEGER_INFO(unsigned char)
697 PROFILE_INTEGER_INFO(short)
698 PROFILE_INTEGER_INFO(unsigned short)
699 PROFILE_INTEGER_INFO(unsigned)
700 PROFILE_INTEGER_INFO(signed)
701 PROFILE_INTEGER_INFO(long)
702 PROFILE_INTEGER_INFO(unsigned long)
703 PROFILE_INTEGER_INFO(long long)
704 PROFILE_INTEGER_INFO(unsigned long long)
706 #undef PROFILE_INTEGER_INFO
708 /// Generic profile trait for pointer types. We treat pointers as
709 /// references to unique objects.
710 template <typename T>
711 struct ImutProfileInfo<T*> {
712 typedef const T* value_type;
713 typedef value_type value_type_ref;
715 static inline void Profile(FoldingSetNodeID &ID, value_type_ref X) {
720 //===----------------------------------------------------------------------===//
721 // Trait classes that contain element comparison operators and type
722 // definitions used by ImutAVLTree, ImmutableSet, and ImmutableMap. These
723 // inherit from the profile traits (ImutProfileInfo) to include operations
724 // for element profiling.
725 //===----------------------------------------------------------------------===//
728 /// ImutContainerInfo - Generic definition of comparison operations for
729 /// elements of immutable containers that defaults to using
730 /// std::equal_to<> and std::less<> to perform comparison of elements.
731 template <typename T>
732 struct ImutContainerInfo : public ImutProfileInfo<T> {
733 typedef typename ImutProfileInfo<T>::value_type value_type;
734 typedef typename ImutProfileInfo<T>::value_type_ref value_type_ref;
735 typedef value_type key_type;
736 typedef value_type_ref key_type_ref;
738 static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
740 static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
741 return std::equal_to<key_type>()(LHS,RHS);
744 static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
745 return std::less<key_type>()(LHS,RHS);
749 /// ImutContainerInfo - Specialization for pointer values to treat pointers
750 /// as references to unique objects. Pointers are thus compared by
752 template <typename T>
753 struct ImutContainerInfo<T*> : public ImutProfileInfo<T*> {
754 typedef typename ImutProfileInfo<T*>::value_type value_type;
755 typedef typename ImutProfileInfo<T*>::value_type_ref value_type_ref;
756 typedef value_type key_type;
757 typedef value_type_ref key_type_ref;
759 static inline key_type_ref KeyOfValue(value_type_ref D) { return D; }
761 static inline bool isEqual(key_type_ref LHS, key_type_ref RHS) {
765 static inline bool isLess(key_type_ref LHS, key_type_ref RHS) {
770 //===----------------------------------------------------------------------===//
772 //===----------------------------------------------------------------------===//
774 template <typename ValT, typename ValInfo = ImutContainerInfo<ValT> >
777 typedef typename ValInfo::value_type value_type;
778 typedef typename ValInfo::value_type_ref value_type_ref;
781 typedef ImutAVLTree<ValInfo> TreeTy;
784 ImmutableSet(TreeTy* R) : Root(R) {}
789 typename TreeTy::Factory F;
794 /// GetEmptySet - Returns an immutable set that contains no elements.
795 ImmutableSet GetEmptySet() { return ImmutableSet(F.GetEmptyTree()); }
797 /// Add - Creates a new immutable set that contains all of the values
798 /// of the original set with the addition of the specified value. If
799 /// the original set already included the value, then the original set is
800 /// returned and no memory is allocated. The time and space complexity
801 /// of this operation is logarithmic in the size of the original set.
802 /// The memory allocated to represent the set is released when the
803 /// factory object that created the set is destroyed.
804 ImmutableSet Add(ImmutableSet Old, value_type_ref V) {
805 return ImmutableSet(F.Add(Old.Root,V));
808 /// Remove - Creates a new immutable set that contains all of the values
809 /// of the original set with the exception of the specified value. If
810 /// the original set did not contain the value, the original set is
811 /// returned and no memory is allocated. The time and space complexity
812 /// of this operation is logarithmic in the size of the original set.
813 /// The memory allocated to represent the set is released when the
814 /// factory object that created the set is destroyed.
815 ImmutableSet Remove(ImmutableSet Old, value_type_ref V) {
816 return ImmutableSet(F.Remove(Old.Root,V));
820 Factory(const Factory& RHS) {};
821 void operator=(const Factory& RHS) {};
824 friend class Factory;
826 /// contains - Returns true if the set contains the specified value.
827 bool contains(const value_type_ref V) const {
828 return Root ? Root->contains(V) : false;
831 bool operator==(ImmutableSet RHS) const {
832 return Root && RHS.Root ? Root->isEqual(*RHS.Root) : Root == RHS.Root;
835 bool operator!=(ImmutableSet RHS) const {
836 return Root && RHS.Root ? Root->isNotEqual(*RHS.Root) : Root != RHS.Root;
839 /// isEmpty - Return true if the set contains no elements.
840 bool isEmpty() const { return !Root; }
842 template <typename Callback>
843 void foreach(Callback& C) { if (Root) Root->foreach(C); }
845 template <typename Callback>
846 void foreach() { if (Root) { Callback C; Root->foreach(C); } }
848 //===--------------------------------------------------===//
850 //===--------------------------------------------------===//
852 void verify() const { if (Root) Root->verify(); }
853 unsigned getHeight() const { return Root ? Root->getHeight() : 0; }
856 } // end namespace llvm