itkEnableIf.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
 *
 *         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 itkEnableIf_h
#define itkEnableIf_h
 
#include "itkMacro.h"
 
#if !defined(ITK_LEGACY_REMOVE)
 
namespace itk
{
namespace mpl
{
 
template <bool V, typename TType = void>
struct EnableIfC
{};
template <typename TType>
struct EnableIfC<true, TType>
{
  using Type = TType;
};
 
 
template <bool V, typename TType = void>
struct DisableIfC
{};
template <typename TType>
struct DisableIfC<false, TType>
{
  using Type = TType;
};
 
template <class TCondition, class TType = void>
struct EnableIf : public EnableIfC<TCondition::Value, TType>
{};
 
template <class TCondition, class TType = void>
struct DisableIf : public DisableIfC<TCondition::Value, TType>
{};
 
} // namespace mpl
 
// itk::EnableIf(C), DisableIf(C) have move to itk::mpl
// Expect them to be deprecated.
using mpl::EnableIf;
using mpl::DisableIf;
using mpl::EnableIfC;
using mpl::DisableIfC;
 
} // namespace itk
 
#else // ITK_LEGACY_REMOVE
#  error Use C++ 11 std::enable_if directly
#endif
 
#endif // itkEnableIf_h