ilist.h revision 7309be6735666143bd9835b275dc8501617a2591
1//==-- llvm/ADT/ilist.h - Intrusive Linked List Template ---------*- C++ -*-==// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines classes to implement an intrusive doubly linked list class 11// (i.e. each node of the list must contain a next and previous field for the 12// list. 13// 14// The ilist_traits trait class is used to gain access to the next and previous 15// fields of the node type that the list is instantiated with. If it is not 16// specialized, the list defaults to using the getPrev(), getNext() method calls 17// to get the next and previous pointers. 18// 19// The ilist class itself, should be a plug in replacement for list, assuming 20// that the nodes contain next/prev pointers. This list replacement does not 21// provide a constant time size() method, so be careful to use empty() when you 22// really want to know if it's empty. 23// 24// The ilist class is implemented by allocating a 'tail' node when the list is 25// created (using ilist_traits<>::createSentinel()). This tail node is 26// absolutely required because the user must be able to compute end()-1. Because 27// of this, users of the direct next/prev links will see an extra link on the 28// end of the list, which should be ignored. 29// 30// Requirements for a user of this list: 31// 32// 1. The user must provide {g|s}et{Next|Prev} methods, or specialize 33// ilist_traits to provide an alternate way of getting and setting next and 34// prev links. 35// 36//===----------------------------------------------------------------------===// 37 38#ifndef LLVM_ADT_ILIST_H 39#define LLVM_ADT_ILIST_H 40 41#include "llvm/ADT/iterator.h" 42#include <cassert> 43 44namespace llvm { 45 46template<typename NodeTy, typename Traits> class iplist; 47template<typename NodeTy> class ilist_iterator; 48 49/// ilist_nextprev_traits - A fragment for template traits for intrusive list 50/// that provides default next/prev implementations for common operations. 51/// 52template<typename NodeTy> 53struct ilist_nextprev_traits { 54 static NodeTy *getPrev(NodeTy *N) { return N->getPrev(); } 55 static NodeTy *getNext(NodeTy *N) { return N->getNext(); } 56 static const NodeTy *getPrev(const NodeTy *N) { return N->getPrev(); } 57 static const NodeTy *getNext(const NodeTy *N) { return N->getNext(); } 58 59 static void setPrev(NodeTy *N, NodeTy *Prev) { N->setPrev(Prev); } 60 static void setNext(NodeTy *N, NodeTy *Next) { N->setNext(Next); } 61}; 62 63template<typename NodeTy> 64struct ilist_traits; 65 66/// ilist_sentinel_traits - A fragment for template traits for intrusive list 67/// that provides default sentinel implementations for common operations. 68/// 69/// ilist_sentinel_traits implements a lazy dynamic sentinel allocation 70/// strategy. The sentinel is stored in the prev field of ilist's Head. 71/// 72template<typename NodeTy> 73struct ilist_sentinel_traits { 74 /// createSentinel - create the dynamic sentinel 75 static NodeTy *createSentinel() { return new NodeTy(); } 76 77 /// destroySentinel - deallocate the dynamic sentinel 78 static void destroySentinel(NodeTy *N) { delete N; } 79 80 /// provideInitialHead - when constructing an ilist, provide a starting 81 /// value for its Head 82 /// @return null node to indicate that it needs to be allocated later 83 static NodeTy *provideInitialHead() { return 0; } 84 85 /// ensureHead - make sure that Head is either already 86 /// initialized or assigned a fresh sentinel 87 /// @return the sentinel 88 static NodeTy *ensureHead(NodeTy *&Head) { 89 if (!Head) { 90 Head = ilist_traits<NodeTy>::createSentinel(); 91 ilist_traits<NodeTy>::noteHead(Head, Head); 92 ilist_traits<NodeTy>::setNext(Head, 0); 93 return Head; 94 } 95 return ilist_traits<NodeTy>::getPrev(Head); 96 } 97 98 /// noteHead - stash the sentinel into its default location 99 static void noteHead(NodeTy *NewHead, NodeTy *Sentinel) { 100 ilist_traits<NodeTy>::setPrev(NewHead, Sentinel); 101 } 102}; 103 104/// ilist_node_traits - A fragment for template traits for intrusive list 105/// that provides default node related operations. 106/// 107template<typename NodeTy> 108struct ilist_node_traits { 109 static NodeTy *createNode(const NodeTy &V) { return new NodeTy(V); } 110 static void deleteNode(NodeTy *V) { delete V; } 111 112 void addNodeToList(NodeTy *) {} 113 void removeNodeFromList(NodeTy *) {} 114 void transferNodesFromList(ilist_node_traits & /*SrcTraits*/, 115 ilist_iterator<NodeTy> /*first*/, 116 ilist_iterator<NodeTy> /*last*/) {} 117}; 118 119/// ilist_default_traits - Default template traits for intrusive list. 120/// By inheriting from this, you can easily use default implementations 121/// for all common operations. 122/// 123template<typename NodeTy> 124struct ilist_default_traits : ilist_nextprev_traits<NodeTy>, 125 ilist_sentinel_traits<NodeTy>, 126 ilist_node_traits<NodeTy> { 127}; 128 129// Template traits for intrusive list. By specializing this template class, you 130// can change what next/prev fields are used to store the links... 131template<typename NodeTy> 132struct ilist_traits : ilist_default_traits<NodeTy> {}; 133 134// Const traits are the same as nonconst traits... 135template<typename Ty> 136struct ilist_traits<const Ty> : public ilist_traits<Ty> {}; 137 138//===----------------------------------------------------------------------===// 139// ilist_iterator<Node> - Iterator for intrusive list. 140// 141template<typename NodeTy> 142class ilist_iterator 143 : public bidirectional_iterator<NodeTy, ptrdiff_t> { 144 145public: 146 typedef ilist_traits<NodeTy> Traits; 147 typedef bidirectional_iterator<NodeTy, ptrdiff_t> super; 148 149 typedef typename super::value_type value_type; 150 typedef typename super::difference_type difference_type; 151 typedef typename super::pointer pointer; 152 typedef typename super::reference reference; 153private: 154 pointer NodePtr; 155 156 // ilist_iterator is not a random-access iterator, but it has an 157 // implicit conversion to pointer-type, which is. Declare (but 158 // don't define) these functions as private to help catch 159 // accidental misuse. 160 void operator[](difference_type) const; 161 void operator+(difference_type) const; 162 void operator-(difference_type) const; 163 void operator+=(difference_type) const; 164 void operator-=(difference_type) const; 165 template<class T> void operator<(T) const; 166 template<class T> void operator<=(T) const; 167 template<class T> void operator>(T) const; 168 template<class T> void operator>=(T) const; 169 template<class T> void operator-(T) const; 170public: 171 172 ilist_iterator(pointer NP) : NodePtr(NP) {} 173 ilist_iterator(reference NR) : NodePtr(&NR) {} 174 ilist_iterator() : NodePtr(0) {} 175 176 // This is templated so that we can allow constructing a const iterator from 177 // a nonconst iterator... 178 template<class node_ty> 179 ilist_iterator(const ilist_iterator<node_ty> &RHS) 180 : NodePtr(RHS.getNodePtrUnchecked()) {} 181 182 // This is templated so that we can allow assigning to a const iterator from 183 // a nonconst iterator... 184 template<class node_ty> 185 const ilist_iterator &operator=(const ilist_iterator<node_ty> &RHS) { 186 NodePtr = RHS.getNodePtrUnchecked(); 187 return *this; 188 } 189 190 // Accessors... 191 operator pointer() const { 192 return NodePtr; 193 } 194 195 reference operator*() const { 196 return *NodePtr; 197 } 198 pointer operator->() const { return &operator*(); } 199 200 // Comparison operators 201 bool operator==(const ilist_iterator &RHS) const { 202 return NodePtr == RHS.NodePtr; 203 } 204 bool operator!=(const ilist_iterator &RHS) const { 205 return NodePtr != RHS.NodePtr; 206 } 207 208 // Increment and decrement operators... 209 ilist_iterator &operator--() { // predecrement - Back up 210 NodePtr = Traits::getPrev(NodePtr); 211 assert(NodePtr && "--'d off the beginning of an ilist!"); 212 return *this; 213 } 214 ilist_iterator &operator++() { // preincrement - Advance 215 NodePtr = Traits::getNext(NodePtr); 216 return *this; 217 } 218 ilist_iterator operator--(int) { // postdecrement operators... 219 ilist_iterator tmp = *this; 220 --*this; 221 return tmp; 222 } 223 ilist_iterator operator++(int) { // postincrement operators... 224 ilist_iterator tmp = *this; 225 ++*this; 226 return tmp; 227 } 228 229 // Internal interface, do not use... 230 pointer getNodePtrUnchecked() const { return NodePtr; } 231}; 232 233// do not implement. this is to catch errors when people try to use 234// them as random access iterators 235template<typename T> 236void operator-(int, ilist_iterator<T>); 237template<typename T> 238void operator-(ilist_iterator<T>,int); 239 240template<typename T> 241void operator+(int, ilist_iterator<T>); 242template<typename T> 243void operator+(ilist_iterator<T>,int); 244 245// operator!=/operator== - Allow mixed comparisons without dereferencing 246// the iterator, which could very likely be pointing to end(). 247template<typename T> 248bool operator!=(const T* LHS, const ilist_iterator<const T> &RHS) { 249 return LHS != RHS.getNodePtrUnchecked(); 250} 251template<typename T> 252bool operator==(const T* LHS, const ilist_iterator<const T> &RHS) { 253 return LHS == RHS.getNodePtrUnchecked(); 254} 255template<typename T> 256bool operator!=(T* LHS, const ilist_iterator<T> &RHS) { 257 return LHS != RHS.getNodePtrUnchecked(); 258} 259template<typename T> 260bool operator==(T* LHS, const ilist_iterator<T> &RHS) { 261 return LHS == RHS.getNodePtrUnchecked(); 262} 263 264 265// Allow ilist_iterators to convert into pointers to a node automatically when 266// used by the dyn_cast, cast, isa mechanisms... 267 268template<typename From> struct simplify_type; 269 270template<typename NodeTy> struct simplify_type<ilist_iterator<NodeTy> > { 271 typedef NodeTy* SimpleType; 272 273 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) { 274 return &*Node; 275 } 276}; 277template<typename NodeTy> struct simplify_type<const ilist_iterator<NodeTy> > { 278 typedef NodeTy* SimpleType; 279 280 static SimpleType getSimplifiedValue(const ilist_iterator<NodeTy> &Node) { 281 return &*Node; 282 } 283}; 284 285 286//===----------------------------------------------------------------------===// 287// 288/// iplist - The subset of list functionality that can safely be used on nodes 289/// of polymorphic types, i.e. a heterogenous list with a common base class that 290/// holds the next/prev pointers. The only state of the list itself is a single 291/// pointer to the head of the list. 292/// 293/// This list can be in one of three interesting states: 294/// 1. The list may be completely unconstructed. In this case, the head 295/// pointer is null. When in this form, any query for an iterator (e.g. 296/// begin() or end()) causes the list to transparently change to state #2. 297/// 2. The list may be empty, but contain a sentinel for the end iterator. This 298/// sentinel is created by the Traits::createSentinel method and is a link 299/// in the list. When the list is empty, the pointer in the iplist points 300/// to the sentinel. Once the sentinel is constructed, it 301/// is not destroyed until the list is. 302/// 3. The list may contain actual objects in it, which are stored as a doubly 303/// linked list of nodes. One invariant of the list is that the predecessor 304/// of the first node in the list always points to the last node in the list, 305/// and the successor pointer for the sentinel (which always stays at the 306/// end of the list) is always null. 307/// 308template<typename NodeTy, typename Traits=ilist_traits<NodeTy> > 309class iplist : public Traits { 310 mutable NodeTy *Head; 311 312 // Use the prev node pointer of 'head' as the tail pointer. This is really a 313 // circularly linked list where we snip the 'next' link from the sentinel node 314 // back to the first node in the list (to preserve assertions about going off 315 // the end of the list). 316 NodeTy *getTail() { return this->ensureHead(Head); } 317 const NodeTy *getTail() const { return this->ensureHead(Head); } 318 void setTail(NodeTy *N) const { this->noteHead(Head, N); } 319 320 /// CreateLazySentinel - This method verifies whether the sentinel for the 321 /// list has been created and lazily makes it if not. 322 void CreateLazySentinel() const { 323 this->ensureHead(Head); 324 } 325 326 static bool op_less(NodeTy &L, NodeTy &R) { return L < R; } 327 static bool op_equal(NodeTy &L, NodeTy &R) { return L == R; } 328 329 // No fundamental reason why iplist can't be copyable, but the default 330 // copy/copy-assign won't do. 331 iplist(const iplist &); // do not implement 332 void operator=(const iplist &); // do not implement 333 334public: 335 typedef NodeTy *pointer; 336 typedef const NodeTy *const_pointer; 337 typedef NodeTy &reference; 338 typedef const NodeTy &const_reference; 339 typedef NodeTy value_type; 340 typedef ilist_iterator<NodeTy> iterator; 341 typedef ilist_iterator<const NodeTy> const_iterator; 342 typedef size_t size_type; 343 typedef ptrdiff_t difference_type; 344 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 345 typedef std::reverse_iterator<iterator> reverse_iterator; 346 347 iplist() : Head(this->provideInitialHead()) {} 348 ~iplist() { 349 if (!Head) return; 350 clear(); 351 Traits::destroySentinel(getTail()); 352 } 353 354 // Iterator creation methods. 355 iterator begin() { 356 CreateLazySentinel(); 357 return iterator(Head); 358 } 359 const_iterator begin() const { 360 CreateLazySentinel(); 361 return const_iterator(Head); 362 } 363 iterator end() { 364 CreateLazySentinel(); 365 return iterator(getTail()); 366 } 367 const_iterator end() const { 368 CreateLazySentinel(); 369 return const_iterator(getTail()); 370 } 371 372 // reverse iterator creation methods. 373 reverse_iterator rbegin() { return reverse_iterator(end()); } 374 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); } 375 reverse_iterator rend() { return reverse_iterator(begin()); } 376 const_reverse_iterator rend() const { return const_reverse_iterator(begin());} 377 378 379 // Miscellaneous inspection routines. 380 size_type max_size() const { return size_type(-1); } 381 bool empty() const { return Head == 0 || Head == getTail(); } 382 383 // Front and back accessor functions... 384 reference front() { 385 assert(!empty() && "Called front() on empty list!"); 386 return *Head; 387 } 388 const_reference front() const { 389 assert(!empty() && "Called front() on empty list!"); 390 return *Head; 391 } 392 reference back() { 393 assert(!empty() && "Called back() on empty list!"); 394 return *this->getPrev(getTail()); 395 } 396 const_reference back() const { 397 assert(!empty() && "Called back() on empty list!"); 398 return *this->getPrev(getTail()); 399 } 400 401 void swap(iplist &RHS) { 402 assert(0 && "Swap does not use list traits callback correctly yet!"); 403 std::swap(Head, RHS.Head); 404 } 405 406 iterator insert(iterator where, NodeTy *New) { 407 NodeTy *CurNode = where.getNodePtrUnchecked(); 408 NodeTy *PrevNode = this->getPrev(CurNode); 409 this->setNext(New, CurNode); 410 this->setPrev(New, PrevNode); 411 412 if (CurNode != Head) // Is PrevNode off the beginning of the list? 413 this->setNext(PrevNode, New); 414 else 415 Head = New; 416 this->setPrev(CurNode, New); 417 418 this->addNodeToList(New); // Notify traits that we added a node... 419 return New; 420 } 421 422 iterator insertAfter(iterator where, NodeTy *New) { 423 if (empty()) 424 return insert(begin(), New); 425 else 426 return insert(++where, New); 427 } 428 429 NodeTy *remove(iterator &IT) { 430 assert(IT != end() && "Cannot remove end of list!"); 431 NodeTy *Node = &*IT; 432 NodeTy *NextNode = this->getNext(Node); 433 NodeTy *PrevNode = this->getPrev(Node); 434 435 if (Node != Head) // Is PrevNode off the beginning of the list? 436 this->setNext(PrevNode, NextNode); 437 else 438 Head = NextNode; 439 this->setPrev(NextNode, PrevNode); 440 IT = NextNode; 441 this->removeNodeFromList(Node); // Notify traits that we removed a node... 442 443 // Set the next/prev pointers of the current node to null. This isn't 444 // strictly required, but this catches errors where a node is removed from 445 // an ilist (and potentially deleted) with iterators still pointing at it. 446 // When those iterators are incremented or decremented, they will assert on 447 // the null next/prev pointer instead of "usually working". 448 this->setNext(Node, 0); 449 this->setPrev(Node, 0); 450 return Node; 451 } 452 453 NodeTy *remove(const iterator &IT) { 454 iterator MutIt = IT; 455 return remove(MutIt); 456 } 457 458 // erase - remove a node from the controlled sequence... and delete it. 459 iterator erase(iterator where) { 460 this->deleteNode(remove(where)); 461 return where; 462 } 463 464 465private: 466 // transfer - The heart of the splice function. Move linked list nodes from 467 // [first, last) into position. 468 // 469 void transfer(iterator position, iplist &L2, iterator first, iterator last) { 470 assert(first != last && "Should be checked by callers"); 471 472 if (position != last) { 473 // Note: we have to be careful about the case when we move the first node 474 // in the list. This node is the list sentinel node and we can't move it. 475 NodeTy *ThisSentinel = getTail(); 476 setTail(0); 477 NodeTy *L2Sentinel = L2.getTail(); 478 L2.setTail(0); 479 480 // Remove [first, last) from its old position. 481 NodeTy *First = &*first, *Prev = this->getPrev(First); 482 NodeTy *Next = last.getNodePtrUnchecked(), *Last = this->getPrev(Next); 483 if (Prev) 484 this->setNext(Prev, Next); 485 else 486 L2.Head = Next; 487 this->setPrev(Next, Prev); 488 489 // Splice [first, last) into its new position. 490 NodeTy *PosNext = position.getNodePtrUnchecked(); 491 NodeTy *PosPrev = this->getPrev(PosNext); 492 493 // Fix head of list... 494 if (PosPrev) 495 this->setNext(PosPrev, First); 496 else 497 Head = First; 498 this->setPrev(First, PosPrev); 499 500 // Fix end of list... 501 this->setNext(Last, PosNext); 502 this->setPrev(PosNext, Last); 503 504 this->transferNodesFromList(L2, First, PosNext); 505 506 // Now that everything is set, restore the pointers to the list sentinels. 507 L2.setTail(L2Sentinel); 508 setTail(ThisSentinel); 509 } 510 } 511 512public: 513 514 //===----------------------------------------------------------------------=== 515 // Functionality derived from other functions defined above... 516 // 517 518 size_type size() const { 519 if (Head == 0) return 0; // Don't require construction of sentinel if empty. 520 return std::distance(begin(), end()); 521 } 522 523 iterator erase(iterator first, iterator last) { 524 while (first != last) 525 first = erase(first); 526 return last; 527 } 528 529 void clear() { if (Head) erase(begin(), end()); } 530 531 // Front and back inserters... 532 void push_front(NodeTy *val) { insert(begin(), val); } 533 void push_back(NodeTy *val) { insert(end(), val); } 534 void pop_front() { 535 assert(!empty() && "pop_front() on empty list!"); 536 erase(begin()); 537 } 538 void pop_back() { 539 assert(!empty() && "pop_back() on empty list!"); 540 iterator t = end(); erase(--t); 541 } 542 543 // Special forms of insert... 544 template<class InIt> void insert(iterator where, InIt first, InIt last) { 545 for (; first != last; ++first) insert(where, *first); 546 } 547 548 // Splice members - defined in terms of transfer... 549 void splice(iterator where, iplist &L2) { 550 if (!L2.empty()) 551 transfer(where, L2, L2.begin(), L2.end()); 552 } 553 void splice(iterator where, iplist &L2, iterator first) { 554 iterator last = first; ++last; 555 if (where == first || where == last) return; // No change 556 transfer(where, L2, first, last); 557 } 558 void splice(iterator where, iplist &L2, iterator first, iterator last) { 559 if (first != last) transfer(where, L2, first, last); 560 } 561 562 563 564 //===----------------------------------------------------------------------=== 565 // High-Level Functionality that shouldn't really be here, but is part of list 566 // 567 568 // These two functions are actually called remove/remove_if in list<>, but 569 // they actually do the job of erase, rename them accordingly. 570 // 571 void erase(const NodeTy &val) { 572 for (iterator I = begin(), E = end(); I != E; ) { 573 iterator next = I; ++next; 574 if (*I == val) erase(I); 575 I = next; 576 } 577 } 578 template<class Pr1> void erase_if(Pr1 pred) { 579 for (iterator I = begin(), E = end(); I != E; ) { 580 iterator next = I; ++next; 581 if (pred(*I)) erase(I); 582 I = next; 583 } 584 } 585 586 template<class Pr2> void unique(Pr2 pred) { 587 if (empty()) return; 588 for (iterator I = begin(), E = end(), Next = begin(); ++Next != E;) { 589 if (pred(*I)) 590 erase(Next); 591 else 592 I = Next; 593 Next = I; 594 } 595 } 596 void unique() { unique(op_equal); } 597 598 template<class Pr3> void merge(iplist &right, Pr3 pred) { 599 iterator first1 = begin(), last1 = end(); 600 iterator first2 = right.begin(), last2 = right.end(); 601 while (first1 != last1 && first2 != last2) 602 if (pred(*first2, *first1)) { 603 iterator next = first2; 604 transfer(first1, right, first2, ++next); 605 first2 = next; 606 } else { 607 ++first1; 608 } 609 if (first2 != last2) transfer(last1, right, first2, last2); 610 } 611 void merge(iplist &right) { return merge(right, op_less); } 612 613 template<class Pr3> void sort(Pr3 pred); 614 void sort() { sort(op_less); } 615 void reverse(); 616}; 617 618 619template<typename NodeTy> 620struct ilist : public iplist<NodeTy> { 621 typedef typename iplist<NodeTy>::size_type size_type; 622 typedef typename iplist<NodeTy>::iterator iterator; 623 624 ilist() {} 625 ilist(const ilist &right) { 626 insert(this->begin(), right.begin(), right.end()); 627 } 628 explicit ilist(size_type count) { 629 insert(this->begin(), count, NodeTy()); 630 } 631 ilist(size_type count, const NodeTy &val) { 632 insert(this->begin(), count, val); 633 } 634 template<class InIt> ilist(InIt first, InIt last) { 635 insert(this->begin(), first, last); 636 } 637 638 // bring hidden functions into scope 639 using iplist<NodeTy>::insert; 640 using iplist<NodeTy>::push_front; 641 using iplist<NodeTy>::push_back; 642 643 // Main implementation here - Insert for a node passed by value... 644 iterator insert(iterator where, const NodeTy &val) { 645 return insert(where, createNode(val)); 646 } 647 648 649 // Front and back inserters... 650 void push_front(const NodeTy &val) { insert(this->begin(), val); } 651 void push_back(const NodeTy &val) { insert(this->end(), val); } 652 653 // Special forms of insert... 654 template<class InIt> void insert(iterator where, InIt first, InIt last) { 655 for (; first != last; ++first) insert(where, *first); 656 } 657 void insert(iterator where, size_type count, const NodeTy &val) { 658 for (; count != 0; --count) insert(where, val); 659 } 660 661 // Assign special forms... 662 void assign(size_type count, const NodeTy &val) { 663 iterator I = this->begin(); 664 for (; I != this->end() && count != 0; ++I, --count) 665 *I = val; 666 if (count != 0) 667 insert(this->end(), val, val); 668 else 669 erase(I, this->end()); 670 } 671 template<class InIt> void assign(InIt first1, InIt last1) { 672 iterator first2 = this->begin(), last2 = this->end(); 673 for ( ; first1 != last1 && first2 != last2; ++first1, ++first2) 674 *first1 = *first2; 675 if (first2 == last2) 676 erase(first1, last1); 677 else 678 insert(last1, first2, last2); 679 } 680 681 682 // Resize members... 683 void resize(size_type newsize, NodeTy val) { 684 iterator i = this->begin(); 685 size_type len = 0; 686 for ( ; i != this->end() && len < newsize; ++i, ++len) /* empty*/ ; 687 688 if (len == newsize) 689 erase(i, this->end()); 690 else // i == end() 691 insert(this->end(), newsize - len, val); 692 } 693 void resize(size_type newsize) { resize(newsize, NodeTy()); } 694}; 695 696} // End llvm namespace 697 698namespace std { 699 // Ensure that swap uses the fast list swap... 700 template<class Ty> 701 void swap(llvm::iplist<Ty> &Left, llvm::iplist<Ty> &Right) { 702 Left.swap(Right); 703 } 704} // End 'std' extensions... 705 706#endif // LLVM_ADT_ILIST_H 707