libaddressinput - reduce number of copies in storage class by 2

base/values.h

 // Copyright (c) 2012 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.
 
 // This file specifies a recursive data storage class called Value intended for
 // storing settings and other persistable data.
 //
 // A Value represents something that can be stored in JSON or passed to/from
 // JavaScript. As such, it is NOT a generalized variant type, since only the
 // types supported by JavaScript/JSON are supported.
@@ skipping 73 matching lines @@
 
   // These methods allow the convenient retrieval of the contents of the Value.
   // If the current object can be converted into the given type, the value is
   // returned through the |out_value| parameter and true is returned;
   // otherwise, false is returned and |out_value| is unchanged.
   virtual bool GetAsBoolean(bool* out_value) const;
   virtual bool GetAsInteger(int* out_value) const;
   virtual bool GetAsDouble(double* out_value) const;
   virtual bool GetAsString(std::string* out_value) const;
   virtual bool GetAsString(string16* out_value) const;
+  virtual bool GetAsString(const StringValue** out_value) const;
   virtual bool GetAsList(ListValue** out_value);
   virtual bool GetAsList(const ListValue** out_value) const;
   virtual bool GetAsDictionary(DictionaryValue** out_value);
   virtual bool GetAsDictionary(const DictionaryValue** out_value) const;
   // Note: Do not add more types. See the file-level comment above for why.
 
   // This creates a deep copy of the entire Value tree, and returns a pointer
   // to the copy.  The caller gets ownership of the copy, of course.
   //
   // Subclasses return their own type directly in their overrides;
@@ skipping 43 matching lines @@
 class BASE_EXPORT StringValue : public Value {
  public:
   // Initializes a StringValue with a UTF-8 narrow character string.
   explicit StringValue(const std::string& in_value);
 
   // Initializes a StringValue with a string16.
   explicit StringValue(const string16& in_value);
 
   virtual ~StringValue();
 
+  // Returns |value_| as a pointer or reference.
+  std::string* GetString();
+  const std::string& GetString() const;
+
   // Overridden from Value:
   virtual bool GetAsString(std::string* out_value) const OVERRIDE;
   virtual bool GetAsString(string16* out_value) const OVERRIDE;
+  virtual bool GetAsString(const StringValue** out_value) const OVERRIDE;
   virtual StringValue* DeepCopy() const OVERRIDE;
   virtual bool Equals(const Value* other) const OVERRIDE;
 
  private:
   std::string value_;
 };
 
 class BASE_EXPORT BinaryValue: public Value {
  public:
   // Creates a BinaryValue with a null buffer and size of 0.
@@ skipping 347 matching lines @@
 }
 
 BASE_EXPORT inline std::ostream& operator<<(std::ostream& out,
                                             const ListValue& value) {
   return out << static_cast<const Value&>(value);
 }
 
 }  // namespace base
 
 #endif  // BASE_VALUES_H_