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//===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file defines the SmallVector class.
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_ADT_SMALLVECTOR_H
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#define LLVM_ADT_SMALLVECTOR_H
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#include "llvm/Support/type_traits.h"
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// Work around flawed VC++ implementation of std::uninitialized_copy. Define
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// additional overloads so that elements with pointer types are recognized as
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// scalars and not objects, causing bizarre type conversion errors.
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template<class T1, class T2>
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inline _Scalar_ptr_iterator_tag _Ptr_cat(T1 **, T2 **) {
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_Scalar_ptr_iterator_tag _Cat;
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template<class T1, class T2>
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inline _Scalar_ptr_iterator_tag _Ptr_cat(T1* const *, T2 **) {
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_Scalar_ptr_iterator_tag _Cat;
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// FIXME: It is not clear if the problem is fixed in VS 2005. What is clear
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// is that the above hack won't work if it wasn't fixed.
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/// SmallVectorBase - This is all the non-templated stuff common to all
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class SmallVectorBase {
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void *BeginX, *EndX, *CapacityX;
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// Allocate raw space for N elements of type T. If T has a ctor or dtor, we
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// don't want it to be automatically run, so we need to represent the space as
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// something else. An array of char would work great, but might not be
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// aligned sufficiently. Instead, we either use GCC extensions, or some
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// number of union instances for the space, which guarantee maximal alignment.
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U FirstEl __attribute__((aligned));
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// Space after 'FirstEl' is clobbered, do not add any instance vars after it.
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SmallVectorBase(size_t Size)
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: BeginX(&FirstEl), EndX(&FirstEl), CapacityX((char*)&FirstEl+Size) {}
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/// isSmall - Return true if this is a smallvector which has not had dynamic
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/// memory allocated for it.
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bool isSmall() const {
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return BeginX == static_cast<const void*>(&FirstEl);
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/// size_in_bytes - This returns size()*sizeof(T).
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size_t size_in_bytes() const {
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return size_t((char*)EndX - (char*)BeginX);
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/// capacity_in_bytes - This returns capacity()*sizeof(T).
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size_t capacity_in_bytes() const {
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return size_t((char*)CapacityX - (char*)BeginX);
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/// grow_pod - This is an implementation of the grow() method which only works
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/// on POD-like datatypes and is out of line to reduce code duplication.
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void grow_pod(size_t MinSizeInBytes, size_t TSize);
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bool empty() const { return BeginX == EndX; }
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template <typename T>
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class SmallVectorTemplateCommon : public SmallVectorBase {
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void setEnd(T *P) { this->EndX = P; }
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SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(Size) {}
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typedef size_t size_type;
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typedef ptrdiff_t difference_type;
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typedef T value_type;
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typedef const T *const_iterator;
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typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
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typedef std::reverse_iterator<iterator> reverse_iterator;
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typedef T &reference;
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typedef const T &const_reference;
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typedef const T *const_pointer;
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// forward iterator creation methods.
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iterator begin() { return (iterator)this->BeginX; }
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const_iterator begin() const { return (const_iterator)this->BeginX; }
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iterator end() { return (iterator)this->EndX; }
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const_iterator end() const { return (const_iterator)this->EndX; }
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iterator capacity_ptr() { return (iterator)this->CapacityX; }
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const_iterator capacity_ptr() const { return (const_iterator)this->CapacityX;}
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// reverse iterator creation methods.
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reverse_iterator rbegin() { return reverse_iterator(end()); }
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const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
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reverse_iterator rend() { return reverse_iterator(begin()); }
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const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
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size_type size() const { return end()-begin(); }
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size_type max_size() const { return size_type(-1) / sizeof(T); }
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/// capacity - Return the total number of elements in the currently allocated
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size_t capacity() const { return capacity_ptr() - begin(); }
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/// data - Return a pointer to the vector's buffer, even if empty().
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pointer data() { return pointer(begin()); }
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/// data - Return a pointer to the vector's buffer, even if empty().
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const_pointer data() const { return const_pointer(begin()); }
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reference operator[](unsigned idx) {
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assert(begin() + idx < end());
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const_reference operator[](unsigned idx) const {
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assert(begin() + idx < end());
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const_reference front() const {
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const_reference back() const {
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/// SmallVectorTemplateBase<isPodLike = false> - This is where we put method
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/// implementations that are designed to work with non-POD-like T's.
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template <typename T, bool isPodLike>
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class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> {
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SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
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static void destroy_range(T *S, T *E) {
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/// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
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/// starting with "Dest", constructing elements into it as needed.
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template<typename It1, typename It2>
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static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
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std::uninitialized_copy(I, E, Dest);
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/// grow - double the size of the allocated memory, guaranteeing space for at
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/// least one more element or MinSize if specified.
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void grow(size_t MinSize = 0);
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// Define this out-of-line to dissuade the C++ compiler from inlining it.
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template <typename T, bool isPodLike>
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void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
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size_t CurCapacity = this->capacity();
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size_t CurSize = this->size();
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size_t NewCapacity = 2*CurCapacity;
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if (NewCapacity < MinSize)
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NewCapacity = MinSize;
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T *NewElts = static_cast<T*>(operator new(NewCapacity*sizeof(T)));
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// Copy the elements over.
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this->uninitialized_copy(this->begin(), this->end(), NewElts);
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// Destroy the original elements.
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destroy_range(this->begin(), this->end());
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// If this wasn't grown from the inline copy, deallocate the old space.
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if (!this->isSmall())
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operator delete(this->begin());
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this->setEnd(NewElts+CurSize);
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this->BeginX = NewElts;
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this->CapacityX = this->begin()+NewCapacity;
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/// SmallVectorTemplateBase<isPodLike = true> - This is where we put method
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/// implementations that are designed to work with POD-like T's.
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template <typename T>
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class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> {
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SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
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// No need to do a destroy loop for POD's.
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static void destroy_range(T *, T *) {}
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/// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
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/// starting with "Dest", constructing elements into it as needed.
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template<typename It1, typename It2>
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static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
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// Use memcpy for PODs: std::uninitialized_copy optimizes to memmove, memcpy
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memcpy(&*Dest, &*I, (E-I)*sizeof(T));
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/// grow - double the size of the allocated memory, guaranteeing space for at
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/// least one more element or MinSize if specified.
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void grow(size_t MinSize = 0) {
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this->grow_pod(MinSize*sizeof(T), sizeof(T));
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/// SmallVectorImpl - This class consists of common code factored out of the
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/// SmallVector class to reduce code duplication based on the SmallVector 'N'
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/// template parameter.
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template <typename T>
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class SmallVectorImpl : public SmallVectorTemplateBase<T, isPodLike<T>::value> {
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typedef SmallVectorTemplateBase<T, isPodLike<T>::value > SuperClass;
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typedef typename SuperClass::iterator iterator;
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typedef typename SuperClass::size_type size_type;
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// Default ctor - Initialize to empty.
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explicit SmallVectorImpl(unsigned N)
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: SmallVectorTemplateBase<T, isPodLike<T>::value>(N*sizeof(T)) {
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// Destroy the constructed elements in the vector.
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this->destroy_range(this->begin(), this->end());
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// If this wasn't grown from the inline copy, deallocate the old space.
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if (!this->isSmall())
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operator delete(this->begin());
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this->destroy_range(this->begin(), this->end());
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this->EndX = this->BeginX;
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void resize(unsigned N) {
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if (N < this->size()) {
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this->destroy_range(this->begin()+N, this->end());
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this->setEnd(this->begin()+N);
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} else if (N > this->size()) {
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if (this->capacity() < N)
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this->construct_range(this->end(), this->begin()+N, T());
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this->setEnd(this->begin()+N);
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void resize(unsigned N, const T &NV) {
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if (N < this->size()) {
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this->destroy_range(this->begin()+N, this->end());
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this->setEnd(this->begin()+N);
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} else if (N > this->size()) {
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if (this->capacity() < N)
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construct_range(this->end(), this->begin()+N, NV);
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this->setEnd(this->begin()+N);
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void reserve(unsigned N) {
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if (this->capacity() < N)
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void push_back(const T &Elt) {
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if (this->EndX < this->CapacityX) {
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new (this->end()) T(Elt);
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this->setEnd(this->end()+1);
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this->setEnd(this->end()-1);
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T Result = this->back();
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void swap(SmallVectorImpl &RHS);
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/// append - Add the specified range to the end of the SmallVector.
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template<typename in_iter>
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void append(in_iter in_start, in_iter in_end) {
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size_type NumInputs = std::distance(in_start, in_end);
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// Grow allocated space if needed.
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if (NumInputs > size_type(this->capacity_ptr()-this->end()))
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this->grow(this->size()+NumInputs);
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// Copy the new elements over.
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// TODO: NEED To compile time dispatch on whether in_iter is a random access
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// iterator to use the fast uninitialized_copy.
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std::uninitialized_copy(in_start, in_end, this->end());
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this->setEnd(this->end() + NumInputs);
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/// append - Add the specified range to the end of the SmallVector.
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void append(size_type NumInputs, const T &Elt) {
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// Grow allocated space if needed.
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if (NumInputs > size_type(this->capacity_ptr()-this->end()))
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this->grow(this->size()+NumInputs);
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// Copy the new elements over.
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std::uninitialized_fill_n(this->end(), NumInputs, Elt);
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this->setEnd(this->end() + NumInputs);
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void assign(unsigned NumElts, const T &Elt) {
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if (this->capacity() < NumElts)
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this->setEnd(this->begin()+NumElts);
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construct_range(this->begin(), this->end(), Elt);
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iterator erase(iterator I) {
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// Shift all elts down one.
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std::copy(I+1, this->end(), I);
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// Drop the last elt.
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iterator erase(iterator S, iterator E) {
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// Shift all elts down.
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iterator I = std::copy(E, this->end(), S);
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// Drop the last elts.
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this->destroy_range(I, this->end());
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iterator insert(iterator I, const T &Elt) {
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if (I == this->end()) { // Important special case for empty vector.
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return this->end()-1;
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if (this->EndX < this->CapacityX) {
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new (this->end()) T(this->back());
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this->setEnd(this->end()+1);
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// Push everything else over.
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std::copy_backward(I, this->end()-1, this->end());
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size_t EltNo = I-this->begin();
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I = this->begin()+EltNo;
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iterator insert(iterator I, size_type NumToInsert, const T &Elt) {
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if (I == this->end()) { // Important special case for empty vector.
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append(NumToInsert, Elt);
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return this->end()-1;
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// Convert iterator to elt# to avoid invalidating iterator when we reserve()
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size_t InsertElt = I - this->begin();
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// Ensure there is enough space.
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reserve(static_cast<unsigned>(this->size() + NumToInsert));
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// Uninvalidate the iterator.
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I = this->begin()+InsertElt;
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// If there are more elements between the insertion point and the end of the
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// range than there are being inserted, we can use a simple approach to
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// insertion. Since we already reserved space, we know that this won't
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// reallocate the vector.
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if (size_t(this->end()-I) >= NumToInsert) {
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T *OldEnd = this->end();
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append(this->end()-NumToInsert, this->end());
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// Copy the existing elements that get replaced.
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std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
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std::fill_n(I, NumToInsert, Elt);
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// Otherwise, we're inserting more elements than exist already, and we're
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// not inserting at the end.
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// Copy over the elements that we're about to overwrite.
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T *OldEnd = this->end();
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this->setEnd(this->end() + NumToInsert);
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size_t NumOverwritten = OldEnd-I;
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this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
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// Replace the overwritten part.
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std::fill_n(I, NumOverwritten, Elt);
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// Insert the non-overwritten middle part.
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std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
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template<typename ItTy>
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iterator insert(iterator I, ItTy From, ItTy To) {
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if (I == this->end()) { // Important special case for empty vector.
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return this->end()-1;
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size_t NumToInsert = std::distance(From, To);
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// Convert iterator to elt# to avoid invalidating iterator when we reserve()
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size_t InsertElt = I - this->begin();
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// Ensure there is enough space.
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reserve(static_cast<unsigned>(this->size() + NumToInsert));
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// Uninvalidate the iterator.
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I = this->begin()+InsertElt;
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// If there are more elements between the insertion point and the end of the
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// range than there are being inserted, we can use a simple approach to
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// insertion. Since we already reserved space, we know that this won't
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// reallocate the vector.
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if (size_t(this->end()-I) >= NumToInsert) {
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T *OldEnd = this->end();
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append(this->end()-NumToInsert, this->end());
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// Copy the existing elements that get replaced.
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std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
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std::copy(From, To, I);
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// Otherwise, we're inserting more elements than exist already, and we're
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// not inserting at the end.
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// Copy over the elements that we're about to overwrite.
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T *OldEnd = this->end();
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this->setEnd(this->end() + NumToInsert);
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size_t NumOverwritten = OldEnd-I;
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this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
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// Replace the overwritten part.
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std::copy(From, From+NumOverwritten, I);
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// Insert the non-overwritten middle part.
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this->uninitialized_copy(From+NumOverwritten, To, OldEnd);
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const SmallVectorImpl
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&operator=(const SmallVectorImpl &RHS);
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bool operator==(const SmallVectorImpl &RHS) const {
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if (this->size() != RHS.size()) return false;
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return std::equal(this->begin(), this->end(), RHS.begin());
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bool operator!=(const SmallVectorImpl &RHS) const {
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return !(*this == RHS);
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bool operator<(const SmallVectorImpl &RHS) const {
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return std::lexicographical_compare(this->begin(), this->end(),
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RHS.begin(), RHS.end());
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/// set_size - Set the array size to \arg N, which the current array must have
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/// enough capacity for.
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/// This does not construct or destroy any elements in the vector.
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/// Clients can use this in conjunction with capacity() to write past the end
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/// of the buffer when they know that more elements are available, and only
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/// update the size later. This avoids the cost of value initializing elements
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/// which will only be overwritten.
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void set_size(unsigned N) {
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assert(N <= this->capacity());
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this->setEnd(this->begin() + N);
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static void construct_range(T *S, T *E, const T &Elt) {
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template <typename T>
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void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) {
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if (this == &RHS) return;
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// We can only avoid copying elements if neither vector is small.
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if (!this->isSmall() && !RHS.isSmall()) {
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std::swap(this->BeginX, RHS.BeginX);
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std::swap(this->EndX, RHS.EndX);
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std::swap(this->CapacityX, RHS.CapacityX);
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if (RHS.size() > this->capacity())
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this->grow(RHS.size());
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if (this->size() > RHS.capacity())
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RHS.grow(this->size());
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// Swap the shared elements.
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size_t NumShared = this->size();
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if (NumShared > RHS.size()) NumShared = RHS.size();
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for (unsigned i = 0; i != static_cast<unsigned>(NumShared); ++i)
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std::swap((*this)[i], RHS[i]);
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// Copy over the extra elts.
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if (this->size() > RHS.size()) {
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size_t EltDiff = this->size() - RHS.size();
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this->uninitialized_copy(this->begin()+NumShared, this->end(), RHS.end());
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RHS.setEnd(RHS.end()+EltDiff);
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this->destroy_range(this->begin()+NumShared, this->end());
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this->setEnd(this->begin()+NumShared);
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} else if (RHS.size() > this->size()) {
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size_t EltDiff = RHS.size() - this->size();
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this->uninitialized_copy(RHS.begin()+NumShared, RHS.end(), this->end());
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this->setEnd(this->end() + EltDiff);
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this->destroy_range(RHS.begin()+NumShared, RHS.end());
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RHS.setEnd(RHS.begin()+NumShared);
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template <typename T>
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const SmallVectorImpl<T> &SmallVectorImpl<T>::
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operator=(const SmallVectorImpl<T> &RHS) {
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// Avoid self-assignment.
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if (this == &RHS) return *this;
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// If we already have sufficient space, assign the common elements, then
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// destroy any excess.
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size_t RHSSize = RHS.size();
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size_t CurSize = this->size();
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if (CurSize >= RHSSize) {
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// Assign common elements.
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NewEnd = std::copy(RHS.begin(), RHS.begin()+RHSSize, this->begin());
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NewEnd = this->begin();
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// Destroy excess elements.
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this->destroy_range(NewEnd, this->end());
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this->setEnd(NewEnd);
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// If we have to grow to have enough elements, destroy the current elements.
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// This allows us to avoid copying them during the grow.
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if (this->capacity() < RHSSize) {
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// Destroy current elements.
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this->destroy_range(this->begin(), this->end());
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this->setEnd(this->begin());
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} else if (CurSize) {
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// Otherwise, use assignment for the already-constructed elements.
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std::copy(RHS.begin(), RHS.begin()+CurSize, this->begin());
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// Copy construct the new elements in place.
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this->uninitialized_copy(RHS.begin()+CurSize, RHS.end(),
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this->begin()+CurSize);
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this->setEnd(this->begin()+RHSSize);
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/// SmallVector - This is a 'vector' (really, a variable-sized array), optimized
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/// for the case when the array is small. It contains some number of elements
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/// in-place, which allows it to avoid heap allocation when the actual number of
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/// elements is below that threshold. This allows normal "small" cases to be
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/// fast without losing generality for large inputs.
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/// Note that this does not attempt to be exception safe.
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template <typename T, unsigned N>
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class SmallVector : public SmallVectorImpl<T> {
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/// InlineElts - These are 'N-1' elements that are stored inline in the body
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/// of the vector. The extra '1' element is stored in SmallVectorImpl.
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typedef typename SmallVectorImpl<T>::U U;
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// MinUs - The number of U's require to cover N T's.
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MinUs = (static_cast<unsigned int>(sizeof(T))*N +
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static_cast<unsigned int>(sizeof(U)) - 1) /
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static_cast<unsigned int>(sizeof(U)),
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// NumInlineEltsElts - The number of elements actually in this array. There
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// is already one in the parent class, and we have to round up to avoid
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// having a zero-element array.
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NumInlineEltsElts = MinUs > 1 ? (MinUs - 1) : 1,
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// NumTsAvailable - The number of T's we actually have space for, which may
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// be more than N due to rounding.
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NumTsAvailable = (NumInlineEltsElts+1)*static_cast<unsigned int>(sizeof(U))/
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static_cast<unsigned int>(sizeof(T))
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U InlineElts[NumInlineEltsElts];
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SmallVector() : SmallVectorImpl<T>(NumTsAvailable) {
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explicit SmallVector(unsigned Size, const T &Value = T())
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: SmallVectorImpl<T>(NumTsAvailable) {
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this->push_back(Value);
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template<typename ItTy>
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SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(NumTsAvailable) {
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SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(NumTsAvailable) {
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SmallVectorImpl<T>::operator=(RHS);
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const SmallVector &operator=(const SmallVector &RHS) {
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SmallVectorImpl<T>::operator=(RHS);
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} // End llvm namespace
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/// Implement std::swap in terms of SmallVector swap.
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swap(llvm::SmallVectorImpl<T> &LHS, llvm::SmallVectorImpl<T> &RHS) {
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/// Implement std::swap in terms of SmallVector swap.
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template<typename T, unsigned N>
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swap(llvm::SmallVector<T, N> &LHS, llvm::SmallVector<T, N> &RHS) {
added
removed
libclamav/c++/llvm/include/llvm/ADT/SmallVector.h
