text: /*
   *  Copyright 2018 NVIDIA Corporation
   *
   *  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.
   */
  
  /*! \file void_t.h
   *  \brief C++17's `void_t`.
   */
  
  #pragma once
  
  #include <thrust/detail/config.h>
  
  #if THRUST_CPP_DIALECT >= 2017
  #  include <type_traits>
  #endif
  
  namespace thrust
  {
  
  #if THRUST_CPP_DIALECT >= 2011
  
  template <typename...> struct voider { using type = void; };
  
  #if THRUST_CPP_DIALECT >= 2017
  using std::void_t;
  #else
  template <typename... Ts> using void_t = typename voider<Ts...>::type;
  #endif
  
  #else // Older than C++11.
  
  template <
    typename = void
  , typename = void
  , typename = void
  , typename = void
  , typename = void
  , typename = void
  , typename = void
  , typename = void
  , typename = void
  , typename = void
  >
  struct voider
  {
    typedef void type;
  };
  
  #endif
  
  } // end namespace thrust
  