Remove mojo::WTFMap.

mojo/public/cpp/bindings/wtf_map.h

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef MOJO_PUBLIC_CPP_BINDINGS_WTF_MAP_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_WTF_MAP_H_
-
-#include <stddef.h>
-#include <utility>
-
-#include "base/macros.h"
-#include "mojo/public/cpp/bindings/lib/template_util.h"
-#include "mojo/public/cpp/bindings/lib/wtf_clone_equals_util.h"
-#include "mojo/public/cpp/bindings/type_converter.h"
-#include "third_party/WebKit/Source/wtf/HashMap.h"
-#include "third_party/WebKit/Source/wtf/text/StringHash.h"
-
-namespace mojo {
-
-// Represents a map backed by WTF::HashMap. Comparing with WTF::HashMap,
-// mojo::WTFMap is move-only and can be null.
-//
-// It is easy to convert between WTF::HashMap<K, V> and mojo::WTFMap<K, V>:
-//   - constructor WTFMap(WTF::HashMap<K, V>&&) takes the contents of a
-//     WTF::HashMap<K, V>;
-//   - method PassStorage() passes the underlying WTF::HashMap.
-//
-// NOTE: WTF::HashMap disallows certain key values. For integer types, those are
-// 0 and -1 (max value instead of -1 for unsigned). For string, that is null.
-template <typename Key, typename Value>
-class WTFMap {
- public:
-  using Iterator = typename WTF::HashMap<Key, Value>::iterator;
-  using ConstIterator = typename WTF::HashMap<Key, Value>::const_iterator;
-
-  // Constructs an empty map.
-  WTFMap() : is_null_(false) {}
-  // Constructs a null map.
-  WTFMap(std::nullptr_t null_pointer) : is_null_(true) {}
-
-  ~WTFMap() {}
-
-  WTFMap(WTF::HashMap<Key, Value>&& other)
-      : map_(std::move(other)), is_null_(false) {}
-  WTFMap(WTFMap&& other) : is_null_(true) { Take(&other); }
-
-  WTFMap& operator=(WTF::HashMap<Key, Value>&& other) {
-    is_null_ = false;
-    map_ = std::move(other);
-    return *this;
-  }
-  WTFMap& operator=(WTFMap&& other) {
-    Take(&other);
-    return *this;
-  }
-
-  WTFMap& operator=(std::nullptr_t null_pointer) {
-    is_null_ = true;
-    map_.clear();
-    return *this;
-  }
-
-  static bool IsValidKey(const Key& key) {
-    return WTF::HashMap<Key, Value>::isValidKey(key);
-  }
-
-  // Copies the contents of some other type of map into a new WTFMap using a
-  // TypeConverter.
-  template <typename U>
-  static WTFMap From(const U& other) {
-    return TypeConverter<WTFMap, U>::Convert(other);
-  }
-
-  // Copies the contents of the WTFMap into some other type of map.
-  template <typename U>
-  U To() const {
-    return TypeConverter<U, WTFMap>::Convert(*this);
-  }
-
-  // Indicates whether the map is null (which is distinct from empty).
-  bool is_null() const { return is_null_; }
-
-  // Indicates whether the map is empty (which is distinct from null).
-  bool empty() const { return map_.isEmpty() && !is_null_; }
-
-  // Indicates the number of keys in the map, which will be zero if the map is
-  // null.
-  size_t size() const { return map_.size(); }
-
-  // Inserts a key-value pair into the map. Like WTF::HashMap::add(), this does
-  // not insert |value| if |key| is already a member of the map.
-  void insert(const Key& key, const Value& value) {
-    is_null_ = false;
-    map_.add(key, value);
-  }
-  void insert(const Key& key, Value&& value) {
-    is_null_ = false;
-    map_.add(key, std::move(value));
-  }
-
-  // Returns a reference to the value associated with the specified key,
-  // crashing the process if the key is not present in the map.
-  Value& at(const Key& key) { return map_.find(key)->value; }
-  const Value& at(const Key& key) const { return map_.find(key)->value; }
-
-  // Returns a reference to the value associated with the specified key,
-  // creating a new entry if the key is not already present in the map. A
-  // newly-created value will be value-initialized (meaning that it will be
-  // initialized by the default constructor of the value type, if any, or else
-  // will be zero-initialized).
-  Value& operator[](const Key& key) {
-    is_null_ = false;
-    if (!map_.contains(key))
-      map_.add(key, Value());
-    return at(key);
-  }
-
-  // Sets the map to empty (even if previously it was null).
-  void SetToEmpty() {
-    is_null_ = false;
-    map_.clear();
-  }
-
-  // Returns a const reference to the WTF::HashMap managed by this class. If
-  // this object is null, the return value will be an empty map.
-  const WTF::HashMap<Key, Value>& storage() const { return map_; }
-
-  // Passes the underlying storage and resets this map to null.
-  WTF::HashMap<Key, Value> PassStorage() {
-    is_null_ = true;
-    return std::move(map_);
-  }
-
-  // Swaps the contents of this WTFMap with another WTFMap of the same type
-  // (including nullness).
-  void Swap(WTFMap<Key, Value>* other) {
-    std::swap(is_null_, other->is_null_);
-    map_.swap(other->map_);
-  }
-
-  // Swaps the contents of this WTFMap with an WTF::HashMap containing keys and
-  // values of the same type. Since WTF::HashMap cannot represent the null
-  // state, the WTF::HashMap will be empty if WTFMap is null. The WTFMap will
-  // always be left in a non-null state.
-  void Swap(WTF::HashMap<Key, Value>* other) {
-    is_null_ = false;
-    map_.swap(*other);
-  }
-
-  // Returns a new WTFMap that contains a copy of the contents of this map. If
-  // the key/value type defines a Clone() method, it will be used; otherwise
-  // copy constructor/assignment will be used.
-  //
-  // Please note that calling this method will fail compilation if the key/value
-  // type cannot be cloned (which usually means that it is a Mojo handle type or
-  // a type containing Mojo handles).
-  WTFMap Clone() const {
-    WTFMap result;
-    result.is_null_ = is_null_;
-    result.map_ = internal::Clone(map_);
-    return result;
-  }
-
-  // Indicates whether the contents of this map are equal to those of another
-  // WTFMap (including nullness). If the key/value type defines an Equals()
-  // method, it will be used; otherwise == operator will be used.
-  bool Equals(const WTFMap& other) const {
-    if (is_null() != other.is_null())
-      return false;
-    return internal::Equals(map_, other.map_);
-  }
-
-  ConstIterator begin() const { return map_.begin(); }
-  Iterator begin() { return map_.begin(); }
-
-  ConstIterator end() const { return map_.end(); }
-  Iterator end() { return map_.end(); }
-
-  // Returns the iterator pointing to the entry for |key|, if present, or else
-  // returns end().
-  ConstIterator find(const Key& key) const { return map_.find(key); }
-  Iterator find(const Key& key) { return map_.find(key); }
-
-  explicit operator bool() const { return !is_null_; }
-
- private:
-  void Take(WTFMap* other) {
-    operator=(nullptr);
-    Swap(other);
-  }
-
-  WTF::HashMap<Key, Value> map_;
-  bool is_null_;
-
-  DISALLOW_COPY_AND_ASSIGN(WTFMap);
-};
-
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_WTF_MAP_H_