chromium源码阅读(3)-scoped_vector

相比原生的vecotr行为，scoped_vector只是增加类在析构时delete其元素的行为。

5   // ScopedVector wraps a vector deleting the elements from its16  // destructor.17  template <class T>18  class ScopedVector {19    MOVE_ONLY_TYPE_FOR_CPP_03(ScopedVector, RValue)20  21   public:22    typedef typename std::vector<T*>::allocator_type allocator_type;23    typedef typename std::vector<T*>::size_type size_type;24    typedef typename std::vector<T*>::difference_type difference_type;25    typedef typename std::vector<T*>::pointer pointer;26    typedef typename std::vector<T*>::const_pointer const_pointer;27    typedef typename std::vector<T*>::reference reference;28    typedef typename std::vector<T*>::const_reference const_reference;29    typedef typename std::vector<T*>::value_type value_type;30    typedef typename std::vector<T*>::iterator iterator;31    typedef typename std::vector<T*>::const_iterator const_iterator;32    typedef typename std::vector<T*>::reverse_iterator reverse_iterator;33    typedef typename std::vector<T*>::const_reverse_iterator34        const_reverse_iterator;35  36    ScopedVector() {}37    ~ScopedVector() { clear(); }38    ScopedVector(RValue other) { swap(*other.object); }39  40    ScopedVector& operator=(RValue rhs) {41      swap(*rhs.object);42      return *this;43    }44  45    reference operator[](size_t index) { return v_[index]; }46    const_reference operator[](size_t index) const { return v_[index]; }47  48    bool empty() const { return v_.empty(); }49    size_t size() const { return v_.size(); }50  51    reverse_iterator rbegin() { return v_.rbegin(); }52    const_reverse_iterator rbegin() const { return v_.rbegin(); }53    reverse_iterator rend() { return v_.rend(); }54    const_reverse_iterator rend() const { return v_.rend(); }55  56    iterator begin() { return v_.begin(); }57    const_iterator begin() const { return v_.begin(); }58    iterator end() { return v_.end(); }59    const_iterator end() const { return v_.end(); }60  61    const_reference front() const { return v_.front(); }62    reference front() { return v_.front(); }63    const_reference back() const { return v_.back(); }64    reference back() { return v_.back(); }65  66    void push_back(T* elem) { v_.push_back(elem); }67  68    void pop_back() {69      DCHECK(!empty());70      delete v_.back();71      v_.pop_back();72    }73  74    std::vector<T*>& get() { return v_; }75    const std::vector<T*>& get() const { return v_; }76    void swap(std::vector<T*>& other) { v_.swap(other); }77    void swap(ScopedVector<T>& other) { v_.swap(other.v_); }78    void release(std::vector<T*>* out) {79      out->swap(v_);80      v_.clear();81    }82  83    void reserve(size_t capacity) { v_.reserve(capacity); }84  85    // Resize, deleting elements in the disappearing range if we are shrinking.86    void resize(size_t new_size) {87      if (v_.size() > new_size)88        STLDeleteContainerPointers(v_.begin() + new_size, v_.end());89      v_.resize(new_size);90    }91  92    template<typename InputIterator>93    void assign(InputIterator begin, InputIterator end) {94      v_.assign(begin, end);95    }96  97    void clear() { STLDeleteElements(&v_); }98  99    // Like |clear()|, but doesn't delete any elements.100   void weak_clear() { v_.clear(); }101 102   // Lets the ScopedVector take ownership of |x|.103   iterator insert(iterator position, T* x) {104     return v_.insert(position, x);105   }106 107   // Lets the ScopedVector take ownership of elements in [first,last).108   template<typename InputIterator>109   void insert(iterator position, InputIterator first, InputIterator last) {110     v_.insert(position, first, last);111   }112 113   iterator erase(iterator position) {114     delete *position;115     return v_.erase(position);116   }117 118   iterator erase(iterator first, iterator last) {119     STLDeleteContainerPointers(first, last);120     return v_.erase(first, last);121   }122 123   // Like |erase()|, but doesn't delete the element at |position|.124   iterator weak_erase(iterator position) {125     return v_.erase(position);126   }127 128   // Like |erase()|, but doesn't delete the elements in [first, last).129   iterator weak_erase(iterator first, iterator last) {130     return v_.erase(first, last);131   }132 133  private:134   std::vector<T*> v_;135 };