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authorGravatar temporal <temporal@630680e5-0e50-0410-840e-4b1c322b438d>2008-07-10 02:12:20 +0000
committerGravatar temporal <temporal@630680e5-0e50-0410-840e-4b1c322b438d>2008-07-10 02:12:20 +0000
commit40ee551715c3a784ea6132dbf604b0e665ca2def (patch)
tree6e3ea9674be5b0f59106f88f3afa1313854beebf /src/google/protobuf/repeated_field.h
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+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.
+// http://code.google.com/p/protobuf/
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Author: kenton@google.com (Kenton Varda)
+// Based on original Protocol Buffers design by
+// Sanjay Ghemawat, Jeff Dean, and others.
+//
+// RepeatedField and RepeatedPtrField are used by generated protocol message
+// classes to manipulate repeated fields. These classes are very similar to
+// STL's vector, but include a number of optimizations found to be useful
+// specifically in the case of Protocol Buffers. RepeatedPtrField is
+// particularly different from STL vector as it manages ownership of the
+// pointers that it contains.
+//
+// Typically, clients should not need to access RepeatedField objects directly,
+// but should instead use the accessor functions generated automatically by the
+// protocol compiler.
+
+#ifndef GOOGLE_PROTOBUF_REPEATED_FIELD_H__
+#define GOOGLE_PROTOBUF_REPEATED_FIELD_H__
+
+#include <string>
+#include <iterator>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/message.h>
+
+
+namespace google {
+namespace protobuf {
+
+namespace internal {
+
+// DO NOT USE GenericRepeatedField; it should be considered a private detail
+// of RepeatedField/RepeatedPtrField that may be removed in the future.
+// GeneratedMessageReflection needs to manipulate repeated fields in a
+// generic way, so we have them implement this interface. This should ONLY
+// be used by GeneratedMessageReflection. This would normally be very bad
+// design but GeneratedMessageReflection is a big efficiency hack anyway.
+//
+// TODO(kenton): Implement something like Jeff's ProtoVoidPtrArray change.
+// Then, get rid of GenericRepeatedField.
+class LIBPROTOBUF_EXPORT GenericRepeatedField {
+ public:
+ inline GenericRepeatedField() {}
+ virtual ~GenericRepeatedField();
+
+ private:
+ // We only want GeneratedMessageReflection to see and use these, so we
+ // make them private. Yes, it is valid C++ for a subclass to implement
+ // a virtual method which is private in the superclass. Crazy, huh?
+ friend class GeneratedMessageReflection;
+
+ virtual const void* GenericGet(int index) const = 0;
+ virtual void* GenericMutable(int index) = 0;
+ virtual void* GenericAdd() = 0;
+ virtual void GenericClear() = 0;
+ virtual int GenericSize() const = 0;
+
+ GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(GenericRepeatedField);
+};
+
+} // namespace internal
+
+// RepeatedField is used to represent repeated fields of a primitive type (in
+// other words, everything except strings and nested Messages). Most users will
+// not ever use a RepeatedField directly; they will use the get-by-index,
+// set-by-index, and add accessors that are generated for all repeated fields.
+template <typename Element>
+class RepeatedField : public internal::GenericRepeatedField {
+ public:
+ RepeatedField();
+ ~RepeatedField();
+
+ int size() const;
+
+ Element Get(int index) const;
+ Element* Mutable(int index);
+ void Set(int index, Element value);
+ void Add(Element value);
+ // Remove the last element in the array.
+ // We don't provide a way to remove any element other than the last
+ // because it invites inefficient use, such as O(n^2) filtering loops
+ // that should have been O(n). If you want to remove an element other
+ // than the last, the best way to do it is to re-arrange the elements
+ // so that the one you want removed is at the end, then call RemoveLast().
+ void RemoveLast();
+ void Clear();
+ void MergeFrom(const RepeatedField& other);
+
+ // Reserve space to expand the field to at least the given size. If the
+ // array is grown, it will always be at least doubled in size.
+ void Reserve(int new_size);
+
+ // Gets the underlying array. This pointer is possibly invalidated by
+ // any add or remove operation.
+ Element* mutable_data();
+ const Element* data() const;
+
+ // Swap entire contents with "other".
+ void Swap(RepeatedField* other);
+
+ // STL-like iterator support
+ typedef Element* iterator;
+ typedef const Element* const_iterator;
+
+ iterator begin();
+ const_iterator begin() const;
+ iterator end();
+ const_iterator end() const;
+
+ private: // See GenericRepeatedField for why this is private.
+ // implements GenericRepeatedField ---------------------------------
+ const void* GenericGet(int index) const;
+ void* GenericMutable(int index);
+ void* GenericAdd();
+ void GenericClear();
+ int GenericSize() const;
+
+ private:
+ GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedField);
+
+ static const int kInitialSize = 4;
+
+ Element* elements_;
+ int current_size_;
+ int total_size_;
+
+ Element initial_space_[kInitialSize];
+};
+
+namespace internal {
+template <typename It> class RepeatedPtrIterator;
+} // namespace internal
+
+// RepeatedPtrField is like RepeatedField, but used for repeated strings or
+// Messages.
+template <typename Element>
+class RepeatedPtrField : public internal::GenericRepeatedField {
+ public:
+ RepeatedPtrField();
+
+ // This constructor is only defined for RepeatedPtrField<Message>.
+ // When a RepeatedPtrField is created using this constructor,
+ // prototype->New() will be called to allocate new elements, rather than
+ // just using the "new" operator. This is useful for the implementation
+ // of DynamicMessage, but is not used by normal generated messages.
+ explicit RepeatedPtrField(const Message* prototype);
+
+ ~RepeatedPtrField();
+
+ // Returns the prototype if one was passed to the constructor.
+ const Message* prototype() const;
+
+ int size() const;
+
+ const Element& Get(int index) const;
+ Element* Mutable(int index);
+ Element* Add();
+ void RemoveLast(); // Remove the last element in the array.
+ void Clear();
+ void MergeFrom(const RepeatedPtrField& other);
+
+ // Reserve space to expand the field to at least the given size. This only
+ // resizes the pointer array; it doesn't allocate any objects. If the
+ // array is grown, it will always be at least doubled in size.
+ void Reserve(int new_size);
+
+ // Gets the underlying array. This pointer is possibly invalidated by
+ // any add or remove operation.
+ Element** mutable_data();
+ const Element* const* data() const;
+
+ // Swap entire contents with "other".
+ void Swap(RepeatedPtrField* other);
+
+ // STL-like iterator support
+ typedef internal::RepeatedPtrIterator<Element**> iterator;
+ typedef internal::RepeatedPtrIterator<const Element* const*> const_iterator;
+
+ iterator begin();
+ const_iterator begin() const;
+ iterator end();
+ const_iterator end() const;
+
+ // Advanced memory management --------------------------------------
+ // When hardcore memory management becomes necessary -- as it often
+ // does here at Google -- the following methods may be useful.
+
+ // Add an already-allocated object, passing ownership to the
+ // RepeatedPtrField.
+ void AddAllocated(Element* value);
+ // Remove the last element and return it, passing ownership to the
+ // caller.
+ // Requires: size() > 0
+ Element* ReleaseLast();
+
+ // When elements are removed by calls to RemoveLast() or Clear(), they
+ // are not actually freed. Instead, they are cleared and kept so that
+ // they can be reused later. This can save lots of CPU time when
+ // repeatedly reusing a protocol message for similar purposes.
+ //
+ // Really, extremely hardcore programs may actually want to manipulate
+ // these objects to better-optimize memory management. These methods
+ // allow that.
+
+ // Get the number of cleared objects that are currently being kept
+ // around for reuse.
+ int ClearedCount();
+ // Add an element to the pool of cleared objects, passing ownership to
+ // the RepeatedPtrField. The element must be cleared prior to calling
+ // this method.
+ void AddCleared(Element* value);
+ // Remove a single element from the cleared pool and return it, passing
+ // ownership to the caller. The element is guaranteed to be cleared.
+ // Requires: ClearedCount() > 0
+ Element* ReleaseCleared();
+
+ private: // See GenericRepeatedField for why this is private.
+ // implements GenericRepeatedField ---------------------------------
+ const void* GenericGet(int index) const;
+ void* GenericMutable(int index);
+ void* GenericAdd();
+ void GenericClear();
+ int GenericSize() const;
+
+ private:
+ GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedPtrField);
+
+ static const int kInitialSize = 4;
+
+ // prototype_ is used for RepeatedPtrField<Message> only (see constructor).
+ const Message* prototype_;
+
+ Element** elements_;
+ int current_size_;
+ int allocated_size_;
+ int total_size_;
+
+ Element* initial_space_[kInitialSize];
+
+ Element* NewElement();
+};
+
+// implementation ====================================================
+
+template <typename Element>
+inline RepeatedField<Element>::RepeatedField()
+ : elements_(initial_space_),
+ current_size_(0),
+ total_size_(kInitialSize) {
+}
+
+template <typename Element>
+RepeatedField<Element>::~RepeatedField() {
+ if (elements_ != initial_space_) {
+ delete [] elements_;
+ }
+}
+
+template <typename Element>
+inline int RepeatedField<Element>::size() const {
+ return current_size_;
+}
+
+
+template <typename Element>
+inline Element RepeatedField<Element>::Get(int index) const {
+ GOOGLE_DCHECK_LT(index, size());
+ return elements_[index];
+}
+
+template <typename Element>
+inline Element* RepeatedField<Element>::Mutable(int index) {
+ GOOGLE_DCHECK_LT(index, size());
+ return elements_ + index;
+}
+
+template <typename Element>
+inline void RepeatedField<Element>::Set(int index, Element value) {
+ GOOGLE_DCHECK_LT(index, size());
+ elements_[index] = value;
+}
+
+template <typename Element>
+inline void RepeatedField<Element>::Add(Element value) {
+ if (current_size_ == total_size_) Reserve(total_size_ + 1);
+ elements_[current_size_++] = value;
+}
+
+template <typename Element>
+inline void RepeatedField<Element>::RemoveLast() {
+ GOOGLE_DCHECK_GT(current_size_, 0);
+ --current_size_;
+}
+
+template <typename Element>
+inline void RepeatedField<Element>::Clear() {
+ current_size_ = 0;
+}
+
+template <typename Element>
+void RepeatedField<Element>::MergeFrom(const RepeatedField& other) {
+ Reserve(current_size_ + other.current_size_);
+ memcpy(elements_ + current_size_, other.elements_,
+ sizeof(Element) * other.current_size_);
+ current_size_ += other.current_size_;
+}
+
+template <typename Element>
+inline Element* RepeatedField<Element>::mutable_data() {
+ return elements_;
+}
+
+template <typename Element>
+inline const Element* RepeatedField<Element>::data() const {
+ return elements_;
+}
+
+
+template <typename Element>
+void RepeatedField<Element>::Swap(RepeatedField* other) {
+ Element* swap_elements = elements_;
+ int swap_current_size = current_size_;
+ int swap_total_size = total_size_;
+ // We may not be using initial_space_ but it's not worth checking. Just
+ // copy it anyway.
+ Element swap_initial_space[kInitialSize];
+ memcpy(swap_initial_space, initial_space_, sizeof(initial_space_));
+
+ elements_ = other->elements_;
+ current_size_ = other->current_size_;
+ total_size_ = other->total_size_;
+ memcpy(initial_space_, other->initial_space_, sizeof(initial_space_));
+
+ other->elements_ = swap_elements;
+ other->current_size_ = swap_current_size;
+ other->total_size_ = swap_total_size;
+ memcpy(other->initial_space_, swap_initial_space, sizeof(swap_initial_space));
+
+ if (elements_ == other->initial_space_) {
+ elements_ = initial_space_;
+ }
+ if (other->elements_ == initial_space_) {
+ other->elements_ = other->initial_space_;
+ }
+}
+
+template <typename Element>
+inline typename RepeatedField<Element>::iterator
+RepeatedField<Element>::begin() {
+ return elements_;
+}
+template <typename Element>
+inline typename RepeatedField<Element>::const_iterator
+RepeatedField<Element>::begin() const {
+ return elements_;
+}
+template <typename Element>
+inline typename RepeatedField<Element>::iterator
+RepeatedField<Element>::end() {
+ return elements_ + current_size_;
+}
+template <typename Element>
+inline typename RepeatedField<Element>::const_iterator
+RepeatedField<Element>::end() const {
+ return elements_ + current_size_;
+}
+
+
+template <typename Element>
+const void* RepeatedField<Element>::GenericGet(int index) const {
+ GOOGLE_DCHECK_LT(index, size());
+ return elements_ + index;
+}
+
+template <typename Element>
+void* RepeatedField<Element>::GenericMutable(int index) {
+ return Mutable(index);
+}
+
+template <typename Element>
+void* RepeatedField<Element>::GenericAdd() {
+ Add(Element());
+ return Mutable(current_size_ - 1);
+}
+
+template <typename Element>
+void RepeatedField<Element>::GenericClear() {
+ Clear();
+}
+
+template <typename Element>
+int RepeatedField<Element>::GenericSize() const {
+ return size();
+}
+
+template <typename Element>
+inline void RepeatedField<Element>::Reserve(int new_size) {
+ if (total_size_ >= new_size) return;
+
+ Element* old_elements = elements_;
+ total_size_ = max(total_size_ * 2, new_size);
+ elements_ = new Element[total_size_];
+ memcpy(elements_, old_elements, current_size_ * sizeof(elements_[0]));
+ if (old_elements != initial_space_) {
+ delete [] old_elements;
+ }
+}
+
+// -------------------------------------------------------------------
+
+template <typename Element>
+inline RepeatedPtrField<Element>::RepeatedPtrField()
+ : prototype_(NULL),
+ elements_(initial_space_),
+ current_size_(0),
+ allocated_size_(0),
+ total_size_(kInitialSize) {
+}
+
+template <>
+inline RepeatedPtrField<Message>::RepeatedPtrField(const Message* prototype)
+ : prototype_(prototype),
+ elements_(initial_space_),
+ current_size_(0),
+ allocated_size_(0),
+ total_size_(kInitialSize) {
+}
+
+template <typename Element>
+RepeatedPtrField<Element>::~RepeatedPtrField() {
+ for (int i = 0; i < allocated_size_; i++) {
+ delete elements_[i];
+ }
+ if (elements_ != initial_space_) {
+ delete [] elements_;
+ }
+}
+
+template <>
+inline const Message* RepeatedPtrField<Message>::prototype() const {
+ return prototype_;
+}
+
+
+template <typename Element>
+inline int RepeatedPtrField<Element>::size() const {
+ return current_size_;
+}
+
+
+template <typename Element>
+inline const Element& RepeatedPtrField<Element>::Get(int index) const {
+ GOOGLE_DCHECK_LT(index, size());
+ return *elements_[index];
+}
+
+template <typename Element>
+inline Element* RepeatedPtrField<Element>::Mutable(int index) {
+ GOOGLE_DCHECK_LT(index, size());
+ return elements_[index];
+}
+
+template <typename Element>
+inline Element* RepeatedPtrField<Element>::Add() {
+ if (current_size_ < allocated_size_) return elements_[current_size_++];
+ if (allocated_size_ == total_size_) Reserve(total_size_ + 1);
+ ++allocated_size_;
+ return elements_[current_size_++] = NewElement();
+}
+
+template <typename Element>
+inline void RepeatedPtrField<Element>::RemoveLast() {
+ GOOGLE_DCHECK_GT(current_size_, 0);
+ elements_[--current_size_]->Clear();
+}
+
+template <>
+inline void RepeatedPtrField<string>::RemoveLast() {
+ GOOGLE_DCHECK_GT(current_size_, 0);
+ elements_[--current_size_]->clear();
+}
+
+template <typename Element>
+void RepeatedPtrField<Element>::Clear() {
+ for (int i = 0; i < current_size_; i++) {
+ elements_[i]->Clear();
+ }
+ current_size_ = 0;
+}
+
+// Specialization defined in repeated_field.cc.
+template <>
+void LIBPROTOBUF_EXPORT RepeatedPtrField<string>::Clear();
+
+template <typename Element>
+void RepeatedPtrField<Element>::MergeFrom(const RepeatedPtrField& other) {
+ Reserve(current_size_ + other.current_size_);
+ for (int i = 0; i < other.current_size_; i++) {
+ Add()->MergeFrom(other.Get(i));
+ }
+}
+
+template <>
+inline void RepeatedPtrField<string>::MergeFrom(const RepeatedPtrField& other) {
+ Reserve(current_size_ + other.current_size_);
+ for (int i = 0; i < other.current_size_; i++) {
+ Add()->assign(other.Get(i));
+ }
+}
+
+
+template <typename Element>
+inline Element** RepeatedPtrField<Element>::mutable_data() {
+ return elements_;
+}
+
+template <typename Element>
+inline const Element* const* RepeatedPtrField<Element>::data() const {
+ return elements_;
+}
+
+
+template <typename Element>
+void RepeatedPtrField<Element>::Swap(RepeatedPtrField* other) {
+ Element** swap_elements = elements_;
+ int swap_current_size = current_size_;
+ int swap_allocated_size = allocated_size_;
+ int swap_total_size = total_size_;
+ // We may not be using initial_space_ but it's not worth checking. Just
+ // copy it anyway.
+ Element* swap_initial_space[kInitialSize];
+ memcpy(swap_initial_space, initial_space_, sizeof(initial_space_));
+
+ elements_ = other->elements_;
+ current_size_ = other->current_size_;
+ allocated_size_ = other->allocated_size_;
+ total_size_ = other->total_size_;
+ memcpy(initial_space_, other->initial_space_, sizeof(initial_space_));
+
+ other->elements_ = swap_elements;
+ other->current_size_ = swap_current_size;
+ other->allocated_size_ = swap_allocated_size;
+ other->total_size_ = swap_total_size;
+ memcpy(other->initial_space_, swap_initial_space, sizeof(swap_initial_space));
+
+ if (elements_ == other->initial_space_) {
+ elements_ = initial_space_;
+ }
+ if (other->elements_ == initial_space_) {
+ other->elements_ = other->initial_space_;
+ }
+}
+
+
+template <typename Element>
+inline void RepeatedPtrField<Element>::AddAllocated(Element* value) {
+ if (allocated_size_ == total_size_) Reserve(total_size_ + 1);
+ // We don't care about the order of cleared elements, so if there's one
+ // in the way, just move it to the back of the array.
+ if (current_size_ < allocated_size_) {
+ elements_[allocated_size_] = elements_[current_size_];
+ }
+ ++allocated_size_;
+ elements_[current_size_++] = value;
+}
+
+template <typename Element>
+inline Element* RepeatedPtrField<Element>::ReleaseLast() {
+ GOOGLE_DCHECK_GT(current_size_, 0);
+ Element* result = elements_[--current_size_];
+ --allocated_size_;
+ if (current_size_ < allocated_size_) {
+ // There are cleared elements on the end; replace the removed element
+ // with the last allocated element.
+ elements_[current_size_] = elements_[allocated_size_];
+ }
+ return result;
+}
+
+
+template <typename Element>
+inline int RepeatedPtrField<Element>::ClearedCount() {
+ return allocated_size_ - current_size_;
+}
+
+template <typename Element>
+inline void RepeatedPtrField<Element>::AddCleared(Element* value) {
+ if (allocated_size_ == total_size_) Reserve(total_size_ + 1);
+ elements_[allocated_size_++] = value;
+}
+
+template <typename Element>
+inline Element* RepeatedPtrField<Element>::ReleaseCleared() {
+ GOOGLE_DCHECK_GT(allocated_size_, current_size_);
+ return elements_[--allocated_size_];
+}
+
+
+template <typename Element>
+const void* RepeatedPtrField<Element>::GenericGet(int index) const {
+ return &Get(index);
+}
+
+template <typename Element>
+void* RepeatedPtrField<Element>::GenericMutable(int index) {
+ return Mutable(index);
+}
+
+template <typename Element>
+void* RepeatedPtrField<Element>::GenericAdd() {
+ return Add();
+}
+
+template <typename Element>
+void RepeatedPtrField<Element>::GenericClear() {
+ Clear();
+}
+
+template <typename Element>
+int RepeatedPtrField<Element>::GenericSize() const {
+ return size();
+}
+
+
+template <typename Element>
+inline void RepeatedPtrField<Element>::Reserve(int new_size) {
+ if (total_size_ >= new_size) return;
+
+ Element** old_elements = elements_;
+ total_size_ = max(total_size_ * 2, new_size);
+ elements_ = new Element*[total_size_];
+ memcpy(elements_, old_elements, allocated_size_ * sizeof(elements_[0]));
+ if (old_elements != initial_space_) {
+ delete [] old_elements;
+ }
+}
+
+template <typename Element>
+inline Element* RepeatedPtrField<Element>::NewElement() {
+ return new Element;
+}
+
+// RepeatedPtrField<Message> is alowed but requires a prototype since Message
+// is abstract.
+template <>
+inline Message* RepeatedPtrField<Message>::NewElement() {
+ return prototype_->New();
+}
+
+// -------------------------------------------------------------------
+
+namespace internal {
+
+// STL-like iterator implementation for RepeatedPtrField. You should not
+// refer to this class directly; use RepeatedPtrField<T>::iterator instead.
+//
+// The iterator for RepeatedPtrField<T>, RepeatedPtrIterator<T**>, is
+// very similar to iterator_ptr<> in util/gtl/iterator_adaptors-inl.h,
+// but adds random-access operators and is slightly more specialized
+// for using T** as its base type. I didn't re-use the other class to
+// avoid an extra dependency.
+//
+// This code stolen from net/proto/proto-array-internal.h by Jeffrey Yasskin
+// (jyasskin@google.com).
+template<typename It>
+class RepeatedPtrIterator
+ : public std::iterator<
+ std::random_access_iterator_tag,
+ typename internal::remove_pointer<
+ typename internal::remove_pointer<It>::type>::type> {
+ public:
+ typedef RepeatedPtrIterator<It> iterator;
+ typedef typename iterator::reference reference;
+ typedef typename iterator::pointer pointer;
+ typedef typename iterator::difference_type difference_type;
+
+ RepeatedPtrIterator() : it_(NULL) {}
+ explicit RepeatedPtrIterator(const It& it) : it_(it) {}
+
+ // Allow "upcasting" from RepeatedPtrIterator<T**> to
+ // RepeatedPtrIterator<const T*const*>.
+ template<typename OtherIt>
+ RepeatedPtrIterator(const RepeatedPtrIterator<OtherIt>& other)
+ : it_(other.base()) {}
+
+ // Provide access to the wrapped iterator.
+ const It& base() const { return it_; }
+
+ // dereferenceable
+ reference operator*() const { return **it_; }
+ pointer operator->() const { return &(operator*()); }
+
+ // {inc,dec}rementable
+ iterator& operator++() { ++it_; return *this; }
+ iterator operator++(int) { return iterator(it_++); }
+ iterator& operator--() { --it_; return *this; }
+ iterator operator--(int) { return iterator(it_--); }
+
+ // equality_comparable
+ bool operator==(const iterator& x) const { return it_ == x.it_; }
+ bool operator!=(const iterator& x) const { return it_ != x.it_; }
+
+ // less_than_comparable
+ bool operator<(const iterator& x) const { return it_ < x.it_; }
+ bool operator<=(const iterator& x) const { return it_ <= x.it_; }
+ bool operator>(const iterator& x) const { return it_ > x.it_; }
+ bool operator>=(const iterator& x) const { return it_ >= x.it_; }
+
+ // addable, subtractable
+ iterator& operator+=(difference_type d) {
+ it_ += d;
+ return *this;
+ }
+ friend iterator operator+(iterator it, difference_type d) {
+ it += d;
+ return it;
+ }
+ friend iterator operator+(difference_type d, iterator it) {
+ it += d;
+ return it;
+ }
+ iterator& operator-=(difference_type d) {
+ it_ -= d;
+ return *this;
+ }
+ friend iterator operator-(iterator it, difference_type d) {
+ it -= d;
+ return it;
+ }
+
+ // indexable
+ reference operator[](difference_type d) const { return *(*this + d); }
+
+ // random access iterator
+ difference_type operator-(const iterator& x) const { return it_ - x.it_; }
+
+ private:
+ // The internal iterator.
+ It it_;
+};
+
+} // namespace internal
+
+template <typename Element>
+inline typename RepeatedPtrField<Element>::iterator
+RepeatedPtrField<Element>::begin() {
+ return iterator(elements_);
+}
+template <typename Element>
+inline typename RepeatedPtrField<Element>::const_iterator
+RepeatedPtrField<Element>::begin() const {
+ return iterator(elements_);
+}
+template <typename Element>
+inline typename RepeatedPtrField<Element>::iterator
+RepeatedPtrField<Element>::end() {
+ return iterator(elements_ + current_size_);
+}
+template <typename Element>
+inline typename RepeatedPtrField<Element>::const_iterator
+RepeatedPtrField<Element>::end() const {
+ return iterator(elements_ + current_size_);
+}
+
+} // namespace protobuf
+
+} // namespace google
+#endif // GOOGLE_PROTOBUF_REPEATED_FIELD_H__