utl/include/utl/meta/void.h

/*!
 * \file    void.h
 * \brief   void_t meta-function
 *
 * Copyright (C) 2018 Christos Choutouridis
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __utl_meta_void_h__
#define __utl_meta_void_h__

#include <utl/core/impl.h>

/*!
 * \ingroup meta
 * \defgroup void
 */
//! @{

namespace utl {
namespace meta {

   /*!
    * void_t meta-function that maps a sequence of any types to the type void
    */
   //! @{
   #if defined(UTL_WORKAROUND_CWG_1558)
      template<typename... _Ts>
      struct void_ {
         using type = void;
      };
      //! void_t type alias
      template<typename... _Ts>
      using void_t = type_of<void_<_Ts...>>;
   #else
      //! void_ type alias
      template <typename...> using void_  = void;
      //! void_t type alias
      template <typename...> using void_t = void;
   #endif
   //! @}
}}
//!@}

#endif /* __utl_meta_void_h__ */