ScopedDeleter.hpp

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 QUICKSTEP_UTILITY_SCOPED_DELETER_HPP_
#define QUICKSTEP_UTILITY_SCOPED_DELETER_HPP_

#include <utility>
#include <vector>

#include "utility/Macros.hpp"

namespace quickstep {

/** \addtogroup Utility
 *  @{
 */

/**
 * @brief RAII helper object that holds pointers to new-allocated objects of
 *        any class and deletes them when it goes out of scope.
 **/
class ScopedDeleter {
 public:
  /**
   * @brief Constructor.
   **/
  ScopedDeleter() {
  }

  /**
   * @brief Destructor. Deletes any objects held by this ScopedDeleter.
   **/
  ~ScopedDeleter() {
    deleteAll();
  }

  /**
   * @brief Add an object to the pool of objects to be deleted by this
   *        ScopedDeleter.
   *
   * @param object A pointer to an object that will be deleted when this
   *        ScopedDeleter goes out of scope. Must be allocated with new and
   *        should not be deleted by any other code.
   **/
  template <typename T>
  inline void addObject(T *object) {
    objects_.emplace_back(&DeleteObject<T>, object);
  }

  /**
   * @brief Create an object and add it to the pool of objects to be deleted by
   *        this ScopedDeleter.
   *
   * @param arguments Forwarded varadic arguments for constructing the object.
   **/
  template <typename T, typename ...ArgTypes>
  inline T* createObject(ArgTypes &&...arguments) {
    T* object = new T(std::forward<ArgTypes>(arguments)...);
    objects_.emplace_back(&DeleteObject<T>, object);
    return object;
  }

  /**
   * @brief Delete all objects held by this ScopedDeleter without destroying
   *        it.
   **/
  void deleteAll() {
    for (std::pair<DeleterFunction, void*> &item : objects_) {
      (*item.first)(item.second);
    }

    objects_.clear();
  }

 private:
  typedef void (*DeleterFunction)(void*);

  template <typename T>
  static void DeleteObject(void *object) {
    delete static_cast<T*>(object);
  }

  std::vector<std::pair<DeleterFunction, void*>> objects_;

  DISALLOW_COPY_AND_ASSIGN(ScopedDeleter);
};

/** @} */

}  // namespace quickstep

#endif  // QUICKSTEP_UTILITY_SCOPED_DELETER_HPP_