glimp/polymorphic_downcast.h

/*
 * Copyright 2023 The Cobalt Authors. All Rights Reserved.
 * Copyright 2014 Google Inc. 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 GLIMP_POLYMORPHIC_DOWNCAST_H_
#define GLIMP_POLYMORPHIC_DOWNCAST_H_

#include "starboard/common/log.h"

namespace nb {

// This function is designed to model the behavior of polymorphic_downcast from
// http://www.boost.org/doc/libs/1_56_0/libs/conversion/cast.htm

template <typename Derived, typename Base>
Derived polymorphic_downcast(Base base) {
#if defined(COBALT_BUILD_TYPE_DEBUG) || defined(COBALT_BUILD_TYPE_DEVEL)
  SB_DCHECK(dynamic_cast<Derived>(base) == base);
#endif
  return static_cast<Derived>(base);
}

}  // namespace nb

#endif  // GLIMP_POLYMORPHIC_DOWNCAST_H_