/*
 * Copyright (c) 2018 Samsung Electronics Co., Ltd. All Rights Reserved
 *
 * 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 __NEURUN_GRAPH_OPERAND_BACKEND_SET_H__
#define __NEURUN_GRAPH_OPERAND_BACKEND_SET_H__

#include <initializer_list>
#include <unordered_set>

namespace neurun
{
namespace backend
{
class Backend;
} // namespace backend
} // namespace neurun

namespace neurun
{
namespace graph
{
namespace operand
{

class BackendSet
{
public:
  BackendSet() = default;
  BackendSet(std::initializer_list<const backend::Backend *> backends);

public:
  void add(const backend::Backend *backend) { _set.insert(backend); }
  void remove(const backend::Backend *backend) { _set.erase(backend); }
  uint32_t size() const { return static_cast<uint32_t>(_set.size()); }
  bool empty() const { return _set.empty(); }
  bool contains(const backend::Backend *backend) const { return _set.find(backend) != _set.end(); }
  const backend::Backend *getOnlyElement() const;

public:
  BackendSet operator|(const BackendSet &other) const; // Union
  BackendSet operator&(const BackendSet &other) const; // Intersect
  BackendSet operator-(const BackendSet &other) const; // Minus

public:
  std::unordered_set<const backend::Backend *>::const_iterator begin() const
  {
    return _set.begin();
  }
  std::unordered_set<const backend::Backend *>::const_iterator end() const { return _set.end(); }

private:
  std::unordered_set<const backend::Backend *> _set;
};

} // namespace operand
} // namespace graph
} // namespace neurun

#endif // __NEURUN_GRAPH_OPERAND_BACKEND_SET_H__