43   typedef std::map<K, PersistentContainerValue> Impl;  typedef
44   typedef typename Impl::iterator Iterator;
46   static bool Empty(Impl* impl) { return impl->empty(); }  in Empty()
47   static size_t Size(Impl* impl) { return impl->size(); }  in Size()
48   static void Swap(Impl& a, Impl& b) { std::swap(a, b); }  // NOLINT  in Swap()
49   static Iterator Begin(Impl* impl) { return impl->begin(); }  in Begin()
50   static Iterator End(Impl* impl) { return impl->end(); }  in End()
53   static PersistentContainerValue Set(Impl* impl, K key,  in Set()
63   static PersistentContainerValue Get(Impl* impl, K key) {  in Get()
68   static PersistentContainerValue Remove(Impl* impl, K key) {  in Remove()
226       typename Traits::Impl impl;
297   typename Traits::Impl* impl() { return &impl_; }
349   typename Traits::Impl impl_;
535   typedef std::vector<PersistentContainerValue> Impl;
537   static void Append(Impl* impl, PersistentContainerValue value) {
540   static bool IsEmpty(const Impl* impl) {
543   static size_t Size(const Impl* impl) {
546   static PersistentContainerValue Get(const Impl* impl, size_t i) {
549   static void ReserveCapacity(Impl* impl, size_t capacity) {
552   static void Clear(Impl* impl) {
645   typename Traits::Impl impl_;