text: // Protocol Buffers - Google's data interchange format
  // Copyright 2008 Google Inc.  All rights reserved.
  // https://developers.google.com/protocol-buffers/
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #ifndef GOOGLE_PROTOBUF_IMPLICIT_WEAK_MESSAGE_H__
  #define GOOGLE_PROTOBUF_IMPLICIT_WEAK_MESSAGE_H__
  
  #include <string>
  
  #include <google/protobuf/io/coded_stream.h>
  #include <google/protobuf/arena.h>
  #include <google/protobuf/message_lite.h>
  #include <google/protobuf/repeated_field.h>
  
  #ifdef SWIG
  #error "You cannot SWIG proto headers"
  #endif
  
  #include <google/protobuf/port_def.inc>
  
  // This file is logically internal-only and should only be used by protobuf
  // generated code.
  
  namespace google {
  namespace protobuf {
  namespace internal {
  
  // An implementation of MessageLite that treats all data as unknown. This type
  // acts as a placeholder for an implicit weak field in the case where the true
  // message type does not get linked into the binary.
  class PROTOBUF_EXPORT ImplicitWeakMessage : public MessageLite {
   public:
    ImplicitWeakMessage() {}
    explicit ImplicitWeakMessage(Arena* arena) : MessageLite(arena) {}
  
    static const ImplicitWeakMessage* default_instance();
  
    std::string GetTypeName() const override { return ""; }
  
    MessageLite* New(Arena* arena) const override {
      return Arena::CreateMessage<ImplicitWeakMessage>(arena);
    }
  
    void Clear() override { data_.clear(); }
  
    bool IsInitialized() const override { return true; }
  
    void CheckTypeAndMergeFrom(const MessageLite& other) override {
      data_.append(static_cast<const ImplicitWeakMessage&>(other).data_);
    }
  
    const char* _InternalParse(const char* ptr, ParseContext* ctx) final;
  
    size_t ByteSizeLong() const override { return data_.size(); }
  
    uint8_t* _InternalSerialize(uint8_t* target,
                                io::EpsCopyOutputStream* stream) const final {
      return stream->WriteRaw(data_.data(), static_cast<int>(data_.size()),
                              target);
    }
  
    int GetCachedSize() const override { return static_cast<int>(data_.size()); }
  
    typedef void InternalArenaConstructable_;
  
   private:
    std::string data_;
    GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(ImplicitWeakMessage);
  };
  
  // A type handler for use with implicit weak repeated message fields.
  template <typename ImplicitWeakType>
  class ImplicitWeakTypeHandler {
   public:
    typedef MessageLite Type;
    static constexpr bool Moveable = false;
  
    static inline MessageLite* NewFromPrototype(const MessageLite* prototype,
                                                Arena* arena = nullptr) {
      return prototype->New(arena);
    }
  
    static inline void Delete(MessageLite* value, Arena* arena) {
      if (arena == nullptr) {
        delete value;
      }
    }
    static inline Arena* GetArena(MessageLite* value) {
      return value->GetArena();
    }
    static inline void Clear(MessageLite* value) { value->Clear(); }
    static void Merge(const MessageLite& from, MessageLite* to) {
      to->CheckTypeAndMergeFrom(from);
    }
  };
  
  }  // namespace internal
  
  template <typename T>
  struct WeakRepeatedPtrField {
    using TypeHandler = internal::ImplicitWeakTypeHandler<T>;
    constexpr WeakRepeatedPtrField() : weak() {}
    explicit WeakRepeatedPtrField(Arena* arena) : weak(arena) {}
    ~WeakRepeatedPtrField() { weak.template Destroy<TypeHandler>(); }
  
    typedef internal::RepeatedPtrIterator<MessageLite> iterator;
    typedef internal::RepeatedPtrIterator<const MessageLite> const_iterator;
    typedef internal::RepeatedPtrOverPtrsIterator<MessageLite*, void*>
        pointer_iterator;
    typedef internal::RepeatedPtrOverPtrsIterator<const MessageLite* const,
                                                  const void* const>
        const_pointer_iterator;
  
    iterator begin() { return iterator(base().raw_data()); }
    const_iterator begin() const { return iterator(base().raw_data()); }
    const_iterator cbegin() const { return begin(); }
    iterator end() { return begin() + base().size(); }
    const_iterator end() const { return begin() + base().size(); }
    const_iterator cend() const { return end(); }
    pointer_iterator pointer_begin() {
      return pointer_iterator(base().raw_mutable_data());
    }
    const_pointer_iterator pointer_begin() const {
      return const_pointer_iterator(base().raw_mutable_data());
    }
    pointer_iterator pointer_end() {
      return pointer_iterator(base().raw_mutable_data() + base().size());
    }
    const_pointer_iterator pointer_end() const {
      return const_pointer_iterator(base().raw_mutable_data() + base().size());
    }
  
    MessageLite* AddWeak(const MessageLite* prototype) {
      return base().AddWeak(prototype);
    }
    T* Add() { return weak.Add(); }
    void Clear() { base().template Clear<TypeHandler>(); }
    void MergeFrom(const WeakRepeatedPtrField& other) {
      base().template MergeFrom<TypeHandler>(other.base());
    }
    void InternalSwap(WeakRepeatedPtrField* other) {
      base().InternalSwap(&other->base());
    }
  
    const internal::RepeatedPtrFieldBase& base() const { return weak; }
    internal::RepeatedPtrFieldBase& base() { return weak; }
    // Union disables running the destructor. Which would create a strong link.
    // Instead we explicitly destroy the underlying base through the virtual
    // destructor.
    union {
      RepeatedPtrField<T> weak;
    };
  };
  
  }  // namespace protobuf
  }  // namespace google
  
  #include <google/protobuf/port_undef.inc>
  
  #endif  // GOOGLE_PROTOBUF_IMPLICIT_WEAK_MESSAGE_H__
  