text: // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
  // Licensed under the MIT License:
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  
  #pragma once
  
  #if defined(__GNUC__) && !KJ_HEADER_WARNINGS
  #pragma GCC system_header
  #endif
  
  #include "array.h"
  
  namespace kj {
  
  template <typename T>
  class Vector {
    // Similar to std::vector, but based on KJ framework.
    //
    // This implementation always uses move constructors when growing the backing array.  If the
    // move constructor throws, the Vector is left in an inconsistent state.  This is acceptable
    // under KJ exception theory which assumes that exceptions leave things in inconsistent states.
  
    // TODO(someday): Allow specifying a custom allocator.
  
  public:
    inline Vector() = default;
    inline explicit Vector(size_t capacity): builder(heapArrayBuilder<T>(capacity)) {}
    inline Vector(Array<T>&& array): builder(kj::mv(array)) {}
  
    inline operator ArrayPtr<T>() { return builder; }
    inline operator ArrayPtr<const T>() const { return builder; }
    inline ArrayPtr<T> asPtr() { return builder.asPtr(); }
    inline ArrayPtr<const T> asPtr() const { return builder.asPtr(); }
  
    inline size_t size() const { return builder.size(); }
    inline bool empty() const { return size() == 0; }
    inline size_t capacity() const { return builder.capacity(); }
    inline T& operator[](size_t index) { return builder[index]; }
    inline const T& operator[](size_t index) const { return builder[index]; }
  
    inline const T* begin() const { return builder.begin(); }
    inline const T* end() const { return builder.end(); }
    inline const T& front() const { return builder.front(); }
    inline const T& back() const { return builder.back(); }
    inline T* begin() { return builder.begin(); }
    inline T* end() { return builder.end(); }
    inline T& front() { return builder.front(); }
    inline T& back() { return builder.back(); }
  
    inline Array<T> releaseAsArray() {
      // TODO(perf):  Avoid a copy/move by allowing Array<T> to point to incomplete space?
      if (!builder.isFull()) {
        setCapacity(size());
      }
      return builder.finish();
    }
  
    template <typename U>
    inline bool operator==(const U& other) const { return asPtr() == other; }
    template <typename U>
    inline bool operator!=(const U& other) const { return asPtr() != other; }
  
    inline ArrayPtr<T> slice(size_t start, size_t end) {
      return asPtr().slice(start, end);
    }
    inline ArrayPtr<const T> slice(size_t start, size_t end) const {
      return asPtr().slice(start, end);
    }
  
    template <typename... Params>
    inline T& add(Params&&... params) {
      if (builder.isFull()) grow();
      return builder.add(kj::fwd<Params>(params)...);
    }
  
    template <typename Iterator>
    inline void addAll(Iterator begin, Iterator end) {
      size_t needed = builder.size() + (end - begin);
      if (needed > builder.capacity()) grow(needed);
      builder.addAll(begin, end);
    }
  
    template <typename Container>
    inline void addAll(Container&& container) {
      addAll(container.begin(), container.end());
    }
  
    inline void removeLast() {
      builder.removeLast();
    }
  
    inline void resize(size_t size) {
      if (size > builder.capacity()) grow(size);
      builder.resize(size);
    }
  
    inline void operator=(decltype(nullptr)) {
      builder = nullptr;
    }
  
    inline void clear() {
      builder.clear();
    }
  
    inline void truncate(size_t size) {
      builder.truncate(size);
    }
  
    inline void reserve(size_t size) {
      if (size > builder.capacity()) {
        setCapacity(size);
      }
    }
  
  private:
    ArrayBuilder<T> builder;
  
    void grow(size_t minCapacity = 0) {
      setCapacity(kj::max(minCapacity, capacity() == 0 ? 4 : capacity() * 2));
    }
    void setCapacity(size_t newSize) {
      if (builder.size() > newSize) {
        builder.truncate(newSize);
      }
      ArrayBuilder<T> newBuilder = heapArrayBuilder<T>(newSize);
      newBuilder.addAll(kj::mv(builder));
      builder = kj::mv(newBuilder);
    }
  };
  
  template <typename T>
  inline auto KJ_STRINGIFY(const Vector<T>& v) -> decltype(toCharSequence(v.asPtr())) {
    return toCharSequence(v.asPtr());
  }
  
  }  // namespace kj
  