SmallVector.h revision 345b378309eabd74a7a43f095dca9a4894bc371e
1//===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- 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 the SmallVector class. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_ADT_SMALLVECTOR_H 15#define LLVM_ADT_SMALLVECTOR_H 16 17#include "llvm/Support/type_traits.h" 18#include <algorithm> 19#include <cassert> 20#include <cstddef> 21#include <cstdlib> 22#include <cstring> 23#include <memory> 24 25#ifdef _MSC_VER 26namespace std { 27#if _MSC_VER <= 1310 28 // Work around flawed VC++ implementation of std::uninitialized_copy. Define 29 // additional overloads so that elements with pointer types are recognized as 30 // scalars and not objects, causing bizarre type conversion errors. 31 template<class T1, class T2> 32 inline _Scalar_ptr_iterator_tag _Ptr_cat(T1 **, T2 **) { 33 _Scalar_ptr_iterator_tag _Cat; 34 return _Cat; 35 } 36 37 template<class T1, class T2> 38 inline _Scalar_ptr_iterator_tag _Ptr_cat(T1* const *, T2 **) { 39 _Scalar_ptr_iterator_tag _Cat; 40 return _Cat; 41 } 42#else 43// FIXME: It is not clear if the problem is fixed in VS 2005. What is clear 44// is that the above hack won't work if it wasn't fixed. 45#endif 46} 47#endif 48 49namespace llvm { 50 51/// SmallVectorBase - This is all the non-templated stuff common to all 52/// SmallVectors. 53class SmallVectorBase { 54protected: 55 void *BeginX, *EndX, *CapacityX; 56 57 // Allocate raw space for N elements of type T. If T has a ctor or dtor, we 58 // don't want it to be automatically run, so we need to represent the space as 59 // something else. An array of char would work great, but might not be 60 // aligned sufficiently. Instead, we either use GCC extensions, or some 61 // number of union instances for the space, which guarantee maximal alignment. 62 struct U { 63#ifdef __GNUC__ 64 char X __attribute__((aligned(8))); 65#else 66 union { 67 double D; 68 long double LD; 69 long long L; 70 void *P; 71 } X; 72#endif 73 } FirstEl; 74 // Space after 'FirstEl' is clobbered, do not add any instance vars after it. 75 76protected: 77 SmallVectorBase(size_t Size) 78 : BeginX(&FirstEl), EndX(&FirstEl), CapacityX((char*)&FirstEl+Size) {} 79 80 /// isSmall - Return true if this is a smallvector which has not had dynamic 81 /// memory allocated for it. 82 bool isSmall() const { 83 return BeginX == static_cast<const void*>(&FirstEl); 84 } 85 86 /// size_in_bytes - This returns size()*sizeof(T). 87 size_t size_in_bytes() const { 88 return size_t((char*)EndX - (char*)BeginX); 89 } 90 91 /// capacity_in_bytes - This returns capacity()*sizeof(T). 92 size_t capacity_in_bytes() const { 93 return size_t((char*)CapacityX - (char*)BeginX); 94 } 95 96 /// grow_pod - This is an implementation of the grow() method which only works 97 /// on POD-like datatypes and is out of line to reduce code duplication. 98 void grow_pod(size_t MinSizeInBytes, size_t TSize); 99 100public: 101 bool empty() const { return BeginX == EndX; } 102}; 103 104 105template <typename T> 106class SmallVectorTemplateCommon : public SmallVectorBase { 107protected: 108 void setEnd(T *P) { this->EndX = P; } 109public: 110 SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(Size) {} 111 112 typedef size_t size_type; 113 typedef ptrdiff_t difference_type; 114 typedef T value_type; 115 typedef T *iterator; 116 typedef const T *const_iterator; 117 118 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 119 typedef std::reverse_iterator<iterator> reverse_iterator; 120 121 typedef T &reference; 122 typedef const T &const_reference; 123 typedef T *pointer; 124 typedef const T *const_pointer; 125 126 // forward iterator creation methods. 127 iterator begin() { return (iterator)this->BeginX; } 128 const_iterator begin() const { return (const_iterator)this->BeginX; } 129 iterator end() { return (iterator)this->EndX; } 130 const_iterator end() const { return (const_iterator)this->EndX; } 131protected: 132 iterator capacity_ptr() { return (iterator)this->CapacityX; } 133 const_iterator capacity_ptr() const { return (const_iterator)this->CapacityX;} 134public: 135 136 // reverse iterator creation methods. 137 reverse_iterator rbegin() { return reverse_iterator(end()); } 138 const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); } 139 reverse_iterator rend() { return reverse_iterator(begin()); } 140 const_reverse_iterator rend() const { return const_reverse_iterator(begin());} 141 142 size_type size() const { return end()-begin(); } 143 size_type max_size() const { return size_type(-1) / sizeof(T); } 144 145 /// capacity - Return the total number of elements in the currently allocated 146 /// buffer. 147 size_t capacity() const { return capacity_ptr() - begin(); } 148 149 /// data - Return a pointer to the vector's buffer, even if empty(). 150 pointer data() { return pointer(begin()); } 151 /// data - Return a pointer to the vector's buffer, even if empty(). 152 const_pointer data() const { return const_pointer(begin()); } 153 154 reference operator[](unsigned idx) { 155 assert(begin() + idx < end()); 156 return begin()[idx]; 157 } 158 const_reference operator[](unsigned idx) const { 159 assert(begin() + idx < end()); 160 return begin()[idx]; 161 } 162 163 reference front() { 164 return begin()[0]; 165 } 166 const_reference front() const { 167 return begin()[0]; 168 } 169 170 reference back() { 171 return end()[-1]; 172 } 173 const_reference back() const { 174 return end()[-1]; 175 } 176}; 177 178/// SmallVectorTemplateBase<isPodLike = false> - This is where we put method 179/// implementations that are designed to work with non-POD-like T's. 180template <typename T, bool isPodLike> 181class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> { 182public: 183 SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {} 184 185 static void destroy_range(T *S, T *E) { 186 while (S != E) { 187 --E; 188 E->~T(); 189 } 190 } 191 192 /// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory 193 /// starting with "Dest", constructing elements into it as needed. 194 template<typename It1, typename It2> 195 static void uninitialized_copy(It1 I, It1 E, It2 Dest) { 196 std::uninitialized_copy(I, E, Dest); 197 } 198 199 /// grow - double the size of the allocated memory, guaranteeing space for at 200 /// least one more element or MinSize if specified. 201 void grow(size_t MinSize = 0); 202}; 203 204// Define this out-of-line to dissuade the C++ compiler from inlining it. 205template <typename T, bool isPodLike> 206void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) { 207 size_t CurCapacity = this->capacity(); 208 size_t CurSize = this->size(); 209 size_t NewCapacity = 2*CurCapacity; 210 if (NewCapacity < MinSize) 211 NewCapacity = MinSize; 212 T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T))); 213 214 // Copy the elements over. 215 this->uninitialized_copy(this->begin(), this->end(), NewElts); 216 217 // Destroy the original elements. 218 destroy_range(this->begin(), this->end()); 219 220 // If this wasn't grown from the inline copy, deallocate the old space. 221 if (!this->isSmall()) 222 free(this->begin()); 223 224 this->setEnd(NewElts+CurSize); 225 this->BeginX = NewElts; 226 this->CapacityX = this->begin()+NewCapacity; 227} 228 229 230/// SmallVectorTemplateBase<isPodLike = true> - This is where we put method 231/// implementations that are designed to work with POD-like T's. 232template <typename T> 233class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> { 234public: 235 SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {} 236 237 // No need to do a destroy loop for POD's. 238 static void destroy_range(T *, T *) {} 239 240 /// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory 241 /// starting with "Dest", constructing elements into it as needed. 242 template<typename It1, typename It2> 243 static void uninitialized_copy(It1 I, It1 E, It2 Dest) { 244 // Arbitrary iterator types; just use the basic implementation. 245 std::uninitialized_copy(I, E, Dest); 246 } 247 248 /// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory 249 /// starting with "Dest", constructing elements into it as needed. 250 template<typename T1, typename T2> 251 static void uninitialized_copy(T1 *I, T1 *E, T2 *Dest) { 252 // Use memcpy for PODs iterated by pointers (which includes SmallVector 253 // iterators): std::uninitialized_copy optimizes to memmove, but we can 254 // use memcpy here. 255 memcpy(Dest, I, (E-I)*sizeof(T)); 256 } 257 258 /// grow - double the size of the allocated memory, guaranteeing space for at 259 /// least one more element or MinSize if specified. 260 void grow(size_t MinSize = 0) { 261 this->grow_pod(MinSize*sizeof(T), sizeof(T)); 262 } 263}; 264 265 266/// SmallVectorImpl - This class consists of common code factored out of the 267/// SmallVector class to reduce code duplication based on the SmallVector 'N' 268/// template parameter. 269template <typename T> 270class SmallVectorImpl : public SmallVectorTemplateBase<T, isPodLike<T>::value> { 271 typedef SmallVectorTemplateBase<T, isPodLike<T>::value > SuperClass; 272public: 273 typedef typename SuperClass::iterator iterator; 274 typedef typename SuperClass::size_type size_type; 275 276 // Default ctor - Initialize to empty. 277 explicit SmallVectorImpl(unsigned N) 278 : SmallVectorTemplateBase<T, isPodLike<T>::value>(N*sizeof(T)) { 279 } 280 281 ~SmallVectorImpl() { 282 // Destroy the constructed elements in the vector. 283 this->destroy_range(this->begin(), this->end()); 284 285 // If this wasn't grown from the inline copy, deallocate the old space. 286 if (!this->isSmall()) 287 free(this->begin()); 288 } 289 290 291 void clear() { 292 this->destroy_range(this->begin(), this->end()); 293 this->EndX = this->BeginX; 294 } 295 296 void resize(unsigned N) { 297 if (N < this->size()) { 298 this->destroy_range(this->begin()+N, this->end()); 299 this->setEnd(this->begin()+N); 300 } else if (N > this->size()) { 301 if (this->capacity() < N) 302 this->grow(N); 303 this->construct_range(this->end(), this->begin()+N, T()); 304 this->setEnd(this->begin()+N); 305 } 306 } 307 308 void resize(unsigned N, const T &NV) { 309 if (N < this->size()) { 310 this->destroy_range(this->begin()+N, this->end()); 311 this->setEnd(this->begin()+N); 312 } else if (N > this->size()) { 313 if (this->capacity() < N) 314 this->grow(N); 315 construct_range(this->end(), this->begin()+N, NV); 316 this->setEnd(this->begin()+N); 317 } 318 } 319 320 void reserve(unsigned N) { 321 if (this->capacity() < N) 322 this->grow(N); 323 } 324 325 void push_back(const T &Elt) { 326 if (this->EndX < this->CapacityX) { 327 Retry: 328 new (this->end()) T(Elt); 329 this->setEnd(this->end()+1); 330 return; 331 } 332 this->grow(); 333 goto Retry; 334 } 335 336 void pop_back() { 337 this->setEnd(this->end()-1); 338 this->end()->~T(); 339 } 340 341 T pop_back_val() { 342 T Result = this->back(); 343 pop_back(); 344 return Result; 345 } 346 347 348 void swap(SmallVectorImpl &RHS); 349 350 /// append - Add the specified range to the end of the SmallVector. 351 /// 352 template<typename in_iter> 353 void append(in_iter in_start, in_iter in_end) { 354 size_type NumInputs = std::distance(in_start, in_end); 355 // Grow allocated space if needed. 356 if (NumInputs > size_type(this->capacity_ptr()-this->end())) 357 this->grow(this->size()+NumInputs); 358 359 // Copy the new elements over. 360 // TODO: NEED To compile time dispatch on whether in_iter is a random access 361 // iterator to use the fast uninitialized_copy. 362 std::uninitialized_copy(in_start, in_end, this->end()); 363 this->setEnd(this->end() + NumInputs); 364 } 365 366 /// append - Add the specified range to the end of the SmallVector. 367 /// 368 void append(size_type NumInputs, const T &Elt) { 369 // Grow allocated space if needed. 370 if (NumInputs > size_type(this->capacity_ptr()-this->end())) 371 this->grow(this->size()+NumInputs); 372 373 // Copy the new elements over. 374 std::uninitialized_fill_n(this->end(), NumInputs, Elt); 375 this->setEnd(this->end() + NumInputs); 376 } 377 378 void assign(unsigned NumElts, const T &Elt) { 379 clear(); 380 if (this->capacity() < NumElts) 381 this->grow(NumElts); 382 this->setEnd(this->begin()+NumElts); 383 construct_range(this->begin(), this->end(), Elt); 384 } 385 386 iterator erase(iterator I) { 387 iterator N = I; 388 // Shift all elts down one. 389 std::copy(I+1, this->end(), I); 390 // Drop the last elt. 391 pop_back(); 392 return(N); 393 } 394 395 iterator erase(iterator S, iterator E) { 396 iterator N = S; 397 // Shift all elts down. 398 iterator I = std::copy(E, this->end(), S); 399 // Drop the last elts. 400 this->destroy_range(I, this->end()); 401 this->setEnd(I); 402 return(N); 403 } 404 405 iterator insert(iterator I, const T &Elt) { 406 if (I == this->end()) { // Important special case for empty vector. 407 push_back(Elt); 408 return this->end()-1; 409 } 410 411 if (this->EndX < this->CapacityX) { 412 Retry: 413 new (this->end()) T(this->back()); 414 this->setEnd(this->end()+1); 415 // Push everything else over. 416 std::copy_backward(I, this->end()-1, this->end()); 417 *I = Elt; 418 return I; 419 } 420 size_t EltNo = I-this->begin(); 421 this->grow(); 422 I = this->begin()+EltNo; 423 goto Retry; 424 } 425 426 iterator insert(iterator I, size_type NumToInsert, const T &Elt) { 427 if (I == this->end()) { // Important special case for empty vector. 428 append(NumToInsert, Elt); 429 return this->end()-1; 430 } 431 432 // Convert iterator to elt# to avoid invalidating iterator when we reserve() 433 size_t InsertElt = I - this->begin(); 434 435 // Ensure there is enough space. 436 reserve(static_cast<unsigned>(this->size() + NumToInsert)); 437 438 // Uninvalidate the iterator. 439 I = this->begin()+InsertElt; 440 441 // If there are more elements between the insertion point and the end of the 442 // range than there are being inserted, we can use a simple approach to 443 // insertion. Since we already reserved space, we know that this won't 444 // reallocate the vector. 445 if (size_t(this->end()-I) >= NumToInsert) { 446 T *OldEnd = this->end(); 447 append(this->end()-NumToInsert, this->end()); 448 449 // Copy the existing elements that get replaced. 450 std::copy_backward(I, OldEnd-NumToInsert, OldEnd); 451 452 std::fill_n(I, NumToInsert, Elt); 453 return I; 454 } 455 456 // Otherwise, we're inserting more elements than exist already, and we're 457 // not inserting at the end. 458 459 // Copy over the elements that we're about to overwrite. 460 T *OldEnd = this->end(); 461 this->setEnd(this->end() + NumToInsert); 462 size_t NumOverwritten = OldEnd-I; 463 this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten); 464 465 // Replace the overwritten part. 466 std::fill_n(I, NumOverwritten, Elt); 467 468 // Insert the non-overwritten middle part. 469 std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt); 470 return I; 471 } 472 473 template<typename ItTy> 474 iterator insert(iterator I, ItTy From, ItTy To) { 475 if (I == this->end()) { // Important special case for empty vector. 476 append(From, To); 477 return this->end()-1; 478 } 479 480 size_t NumToInsert = std::distance(From, To); 481 // Convert iterator to elt# to avoid invalidating iterator when we reserve() 482 size_t InsertElt = I - this->begin(); 483 484 // Ensure there is enough space. 485 reserve(static_cast<unsigned>(this->size() + NumToInsert)); 486 487 // Uninvalidate the iterator. 488 I = this->begin()+InsertElt; 489 490 // If there are more elements between the insertion point and the end of the 491 // range than there are being inserted, we can use a simple approach to 492 // insertion. Since we already reserved space, we know that this won't 493 // reallocate the vector. 494 if (size_t(this->end()-I) >= NumToInsert) { 495 T *OldEnd = this->end(); 496 append(this->end()-NumToInsert, this->end()); 497 498 // Copy the existing elements that get replaced. 499 std::copy_backward(I, OldEnd-NumToInsert, OldEnd); 500 501 std::copy(From, To, I); 502 return I; 503 } 504 505 // Otherwise, we're inserting more elements than exist already, and we're 506 // not inserting at the end. 507 508 // Copy over the elements that we're about to overwrite. 509 T *OldEnd = this->end(); 510 this->setEnd(this->end() + NumToInsert); 511 size_t NumOverwritten = OldEnd-I; 512 this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten); 513 514 // Replace the overwritten part. 515 for (; NumOverwritten > 0; --NumOverwritten) { 516 *I = *From; 517 ++I; ++From; 518 } 519 520 // Insert the non-overwritten middle part. 521 this->uninitialized_copy(From, To, OldEnd); 522 return I; 523 } 524 525 const SmallVectorImpl 526 &operator=(const SmallVectorImpl &RHS); 527 528 bool operator==(const SmallVectorImpl &RHS) const { 529 if (this->size() != RHS.size()) return false; 530 return std::equal(this->begin(), this->end(), RHS.begin()); 531 } 532 bool operator!=(const SmallVectorImpl &RHS) const { 533 return !(*this == RHS); 534 } 535 536 bool operator<(const SmallVectorImpl &RHS) const { 537 return std::lexicographical_compare(this->begin(), this->end(), 538 RHS.begin(), RHS.end()); 539 } 540 541 /// set_size - Set the array size to \arg N, which the current array must have 542 /// enough capacity for. 543 /// 544 /// This does not construct or destroy any elements in the vector. 545 /// 546 /// Clients can use this in conjunction with capacity() to write past the end 547 /// of the buffer when they know that more elements are available, and only 548 /// update the size later. This avoids the cost of value initializing elements 549 /// which will only be overwritten. 550 void set_size(unsigned N) { 551 assert(N <= this->capacity()); 552 this->setEnd(this->begin() + N); 553 } 554 555private: 556 static void construct_range(T *S, T *E, const T &Elt) { 557 for (; S != E; ++S) 558 new (S) T(Elt); 559 } 560}; 561 562 563template <typename T> 564void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) { 565 if (this == &RHS) return; 566 567 // We can only avoid copying elements if neither vector is small. 568 if (!this->isSmall() && !RHS.isSmall()) { 569 std::swap(this->BeginX, RHS.BeginX); 570 std::swap(this->EndX, RHS.EndX); 571 std::swap(this->CapacityX, RHS.CapacityX); 572 return; 573 } 574 if (RHS.size() > this->capacity()) 575 this->grow(RHS.size()); 576 if (this->size() > RHS.capacity()) 577 RHS.grow(this->size()); 578 579 // Swap the shared elements. 580 size_t NumShared = this->size(); 581 if (NumShared > RHS.size()) NumShared = RHS.size(); 582 for (unsigned i = 0; i != static_cast<unsigned>(NumShared); ++i) 583 std::swap((*this)[i], RHS[i]); 584 585 // Copy over the extra elts. 586 if (this->size() > RHS.size()) { 587 size_t EltDiff = this->size() - RHS.size(); 588 this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end()); 589 RHS.setEnd(RHS.end()+EltDiff); 590 this->destroy_range(this->begin()+NumShared, this->end()); 591 this->setEnd(this->begin()+NumShared); 592 } else if (RHS.size() > this->size()) { 593 size_t EltDiff = RHS.size() - this->size(); 594 this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end()); 595 this->setEnd(this->end() + EltDiff); 596 this->destroy_range(RHS.begin()+NumShared, RHS.end()); 597 RHS.setEnd(RHS.begin()+NumShared); 598 } 599} 600 601template <typename T> 602const SmallVectorImpl<T> &SmallVectorImpl<T>:: 603 operator=(const SmallVectorImpl<T> &RHS) { 604 // Avoid self-assignment. 605 if (this == &RHS) return *this; 606 607 // If we already have sufficient space, assign the common elements, then 608 // destroy any excess. 609 size_t RHSSize = RHS.size(); 610 size_t CurSize = this->size(); 611 if (CurSize >= RHSSize) { 612 // Assign common elements. 613 iterator NewEnd; 614 if (RHSSize) 615 NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin()); 616 else 617 NewEnd = this->begin(); 618 619 // Destroy excess elements. 620 this->destroy_range(NewEnd, this->end()); 621 622 // Trim. 623 this->setEnd(NewEnd); 624 return *this; 625 } 626 627 // If we have to grow to have enough elements, destroy the current elements. 628 // This allows us to avoid copying them during the grow. 629 if (this->capacity() < RHSSize) { 630 // Destroy current elements. 631 this->destroy_range(this->begin(), this->end()); 632 this->setEnd(this->begin()); 633 CurSize = 0; 634 this->grow(RHSSize); 635 } else if (CurSize) { 636 // Otherwise, use assignment for the already-constructed elements. 637 std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin()); 638 } 639 640 // Copy construct the new elements in place. 641 this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(), 642 this->begin()+CurSize); 643 644 // Set end. 645 this->setEnd(this->begin()+RHSSize); 646 return *this; 647} 648 649 650/// SmallVector - This is a 'vector' (really, a variable-sized array), optimized 651/// for the case when the array is small. It contains some number of elements 652/// in-place, which allows it to avoid heap allocation when the actual number of 653/// elements is below that threshold. This allows normal "small" cases to be 654/// fast without losing generality for large inputs. 655/// 656/// Note that this does not attempt to be exception safe. 657/// 658template <typename T, unsigned N> 659class SmallVector : public SmallVectorImpl<T> { 660 /// InlineElts - These are 'N-1' elements that are stored inline in the body 661 /// of the vector. The extra '1' element is stored in SmallVectorImpl. 662 typedef typename SmallVectorImpl<T>::U U; 663 enum { 664 // MinUs - The number of U's require to cover N T's. 665 MinUs = (static_cast<unsigned int>(sizeof(T))*N + 666 static_cast<unsigned int>(sizeof(U)) - 1) / 667 static_cast<unsigned int>(sizeof(U)), 668 669 // NumInlineEltsElts - The number of elements actually in this array. There 670 // is already one in the parent class, and we have to round up to avoid 671 // having a zero-element array. 672 NumInlineEltsElts = MinUs > 1 ? (MinUs - 1) : 1, 673 674 // NumTsAvailable - The number of T's we actually have space for, which may 675 // be more than N due to rounding. 676 NumTsAvailable = (NumInlineEltsElts+1)*static_cast<unsigned int>(sizeof(U))/ 677 static_cast<unsigned int>(sizeof(T)) 678 }; 679 U InlineElts[NumInlineEltsElts]; 680public: 681 SmallVector() : SmallVectorImpl<T>(NumTsAvailable) { 682 } 683 684 explicit SmallVector(unsigned Size, const T &Value = T()) 685 : SmallVectorImpl<T>(NumTsAvailable) { 686 this->reserve(Size); 687 while (Size--) 688 this->push_back(Value); 689 } 690 691 template<typename ItTy> 692 SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(NumTsAvailable) { 693 this->append(S, E); 694 } 695 696 SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(NumTsAvailable) { 697 if (!RHS.empty()) 698 SmallVectorImpl<T>::operator=(RHS); 699 } 700 701 const SmallVector &operator=(const SmallVector &RHS) { 702 SmallVectorImpl<T>::operator=(RHS); 703 return *this; 704 } 705 706}; 707 708} // End llvm namespace 709 710namespace std { 711 /// Implement std::swap in terms of SmallVector swap. 712 template<typename T> 713 inline void 714 swap(llvm::SmallVectorImpl<T> &LHS, llvm::SmallVectorImpl<T> &RHS) { 715 LHS.swap(RHS); 716 } 717 718 /// Implement std::swap in terms of SmallVector swap. 719 template<typename T, unsigned N> 720 inline void 721 swap(llvm::SmallVector<T, N> &LHS, llvm::SmallVector<T, N> &RHS) { 722 LHS.swap(RHS); 723 } 724} 725 726#endif 727