sitkConditional.h

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/*=========================================================================
 *
 *  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
 *
 *         http://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 sitkConditional_h
#define sitkConditional_h
 
#include <type_traits>
 
namespace itk::simple
{
 
/* \brief An object for selecting an integer value at compile-time.
 *
 *
 * If VCode is true, then the member Value will be TIfTrue, otherwise
 * the member Value  will be equivalent to TIfFalse.
 *
 * This class also contains a typedef for ValueType, which is an the
 * selected integral constant as a type.
 */
template <bool VCond, int TIfTrue, int TIfFalse>
struct ConditionalValue
{
private:
  using Self = ConditionalValue;
  typedef
    typename std::conditional<VCond, std::integral_constant<int, TIfTrue>, std::integral_constant<int, TIfFalse>>::type
      ConditionalType;
 
public:
  using Type = typename ConditionalType::type;
  using ValueType = typename ConditionalType::value_type;
 
  static const ValueType Value = ConditionalType::value;
};
 
 
} // namespace itk::simple
 
#endif // sitkConditional_h