utl/include/utl/meta/integral.h

/*!
 * \file    integral.h
 * \brief   Template meta-programming integral constant
 *
 * 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_integral_h__
#define __utl_meta_integral_h__

#include <utl/impl/version.h>

/*!
 * \ingroup meta
 * \defgroup integral
 * integral constand support header
 */
//! @{

namespace utl {

   //! integral_constant
   template <typename _Tp, _Tp _v>
   struct integral_ {
      using value_type = _Tp;
      using type       = integral_<_Tp, _v>;

      constexpr operator value_type() const {
         return value;
      }
      constexpr value_type operator()() const {
         return value;
      }
      static constexpr _Tp value = _v;
   };

   template<typename _Tp, _Tp _v>
   constexpr _Tp integral_<_Tp, _v>::value;
}
//!@}

#endif /* __utl_meta_integral_h__ */