itkMakeUniqueForOverwrite.h

Go to the documentation of this file.

/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  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
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  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 itkMakeUniqueForOverwrite_h
#define itkMakeUniqueForOverwrite_h
 
#include <memory> // For unique_ptr.
 
#if __cplusplus < 202002L
 
#  include <type_traits> // For remove_extent_t, false_type, etc.
 
namespace itk
{
 
// Namespace of implementation details (not part of the public ITK interface).
namespace MakeUniqueForOverwriteImplDetail
{
 
// `is_unbounded_array` implementation for C++14/C++17. From C++20, `std::is_unbounded_array` is preferred.
template <typename>
struct is_unbounded_array : std::false_type
{};
 
template <typename T>
struct is_unbounded_array<T[]> : std::true_type
{};
 
} // namespace MakeUniqueForOverwriteImplDetail
 
 
     // Create a buffer that may be used to store the specified number of elements.
     auto buffer = make_unique_for_overwrite<ElementType[]>(numberOfElements);
   \endcode
 *
 */
template <typename TUnboundedArray>
auto
make_unique_for_overwrite(const size_t numberOfElements)
{
  // The template argument must be something like `ElementType[]`, having an empty pair of square brackets.
  static_assert(MakeUniqueForOverwriteImplDetail::is_unbounded_array<TUnboundedArray>::value,
                "The specified template argument must be an unbounded array type!");
  return std::unique_ptr<TUnboundedArray>(new std::remove_extent_t<TUnboundedArray>[numberOfElements]);
}
 
} // namespace itk
 
#else
 
namespace itk
{
using ::std::make_unique_for_overwrite;
}
 
#endif
 
#endif // itkMakeUniqueForOverwrite_h