RulesRegistry for declarative APIs.

chrome/browser/extensions/api/declarative/rule_identifier.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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULE_IDENTIFIER_H__
+#define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULE_IDENTIFIER_H__
+#pragma once
+
+#include <string>
+
+namespace extensions {
+
+// A globally unique rule identifier
+class RuleIdentifier {
+ public:
+  RuleIdentifier(const std::string& extension_id,
+                 const std::string& event_name,
+                 const std::string& rule_id);
+  RuleIdentifier(const RuleIdentifier& other);
+  ~RuleIdentifier();
+
+  const std::string& extension_id() const { return extension_id_; }
+  const std::string& event_name() const { return event_name_; }
+  const std::string& rule_id() const { return rule_id_; }
+
+  bool operator<(const RuleIdentifier& other) const;

[not at google - send to devlin, 2012/02/02 11:59:16]

why do you need to overload < ?

[Aaron Boodman, 2012/02/02 16:28:51]

It is so that RuleIdentifier can be used with std::set.

[battre, 2012/02/02 19:12:36]

To store these elements in a std::set.

[not at google - send to devlin, 2012/02/03 13:06:20]

I see.

I'm idly wondering whether it's possible to use strings as IDs rather than these
structs; like

std::string id = extention_id + "/" + event_name + "/" + rule_id;

but just idly, I haven't looked at the uses of this in much detail.

+  RuleIdentifier& operator=(const RuleIdentifier& other);

[not at google - send to devlin, 2012/02/02 11:59:16]

i don't think you need to override this.

[Aaron Boodman, 2012/02/02 16:28:51]

Not sure about this one. Maybe some other STL container.

[battre, 2012/02/02 19:12:36]

I think the style guide is not exactly clear, but I read
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Copy_C...
as "we want both an no implicit assignment operator"

+ private:
+  std::string extension_id_;
+  std::string event_name_;
+  std::string rule_id_;
+};
+
+}  // extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULE_IDENTIFIER_H__