enum_set.h

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/*
 * Copyright 2013 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http:///www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef PAGESPEED_KERNEL_BASE_ENUM_SET_H_
#define PAGESPEED_KERNEL_BASE_ENUM_SET_H_

#include <bitset>
#include <cstddef>

namespace net_instaweb {

template<typename EnumType, size_t NumEnums> class EnumSet {
 public:
  bool IsSet(EnumType value) const {
    return bits_.test(static_cast<size_t>(value));
  }

  bool Insert(EnumType value) {
    bool result = !IsSet(value);
    insert(value);
    return result;
  }

  void insert(EnumType value) {
    bits_.set(static_cast<size_t>(value));
  }

  bool Erase(EnumType value) {
    bool result = IsSet(value);
    bits_.reset(static_cast<size_t>(value));
    return result;
  }

  bool Merge(const EnumSet& src) {
    EnumSet save(*this);
    bits_ |= src.bits_;
    return bits_ != save.bits_;
  }

  bool MergeInverted(const EnumSet& src) {
    EnumSet save(*this);
    bits_ |= ~src.bits_;
    return bits_ != save.bits_;
  }

  void EraseSet(const EnumSet& src) {
    bits_ &= ~src.bits_;
  }

  void SetAll() {
    bits_.set();
  }

  void clear() { bits_.reset(); }
  size_t size() const { return bits_.count(); }
  bool empty() const { return bits_.none(); }

  bool operator==(const EnumSet& that) const {
    return bits_ == that.bits_;
  }

 private:
  typedef std::bitset<NumEnums> BitSet;
  BitSet bits_;

};

}  

#endif