chromium/extensions/common/value_counter.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef EXTENSIONS_COMMON_VALUE_COUNTER_H_
#define EXTENSIONS_COMMON_VALUE_COUNTER_H_

#include <vector>

namespace base {
class Value;
}

namespace extensions {

// Keeps a running count of Values, like map<Value, int>. Adding/removing
// values increments/decrements the count associated with a given Value.
//
// Add() and Remove() are linear in the number of Values in the ValueCounter,
// because there is no operator<() defined on Value, so we must iterate to find
// whether a Value is equal to an existing one.
class ValueCounter { … };

}  // namespace extensions

#endif  // EXTENSIONS_COMMON_VALUE_COUNTER_H_