/*!
 * \file    operators.h
 * \brief   Template meta-programming integral constant arithmetic
 *
 * 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_arithmetic_h__
#define __utl_meta_arithmetic_h__

#include <utl/core/impl.h>
#include <utl/meta/logical.h>

/*!
 * \ingroup meta
 * \defgroup integral operators
 * Type arithmetic and operators
 */
//! @{

namespace utl {
namespace meta {

    /*!
     * Math operations
     * requires IntegralConstant(_Tp)
     */
   //! @{

   //! Negation
   template <typename _Tp>
   using negate = integral_constant<decltype(-_Tp()), -_Tp()>;
   //! Addition
   template <typename _Tp1, typename _Tp2>
   using add = integral_constant<
                  decltype(_Tp1() + _Tp2()),
                  _Tp1() + _Tp2()
               >;
   //! Multiplication
   template <typename _Tp1, typename _Tp2>
   using mult = integral_constant<
                   decltype(_Tp2() * _Tp2()),
                   _Tp1() * _Tp2()
                >;
   //! Division
   template <typename _Tp1, typename _Tp2>
   using divide = integral_constant<
                     decltype(_Tp2() / _Tp2()),
                     _Tp1() / _Tp2()
                  >;
    //! Modulo
    template <typename _Tp1, typename _Tp2>
    using modulo = integral_constant<
                      decltype(_Tp1() % _Tp2()),
                      _Tp1() % _Tp2()
                   >;
   //! Substruction
   template <typename _Tp1, typename _Tp2>
   using sub = add<_Tp1, negate<_Tp2>>;

   //! Increase
   template <typename _Tp>
   using inc = add<_Tp, int_<1>>;

   //! decrease
   template <typename _Tp>
   using dec = add<_Tp, int_<-1>>;

   //! @}

   /*!
    * Comparison operations
    * requires IntegralConstant(_Tp)
    */
   //! @{

   //! \return a true-valued Integral Constant if _Tp1 and _Tp2 are equal.
   template <typename _Tp1, typename _Tp2>   using comp_eq = bool_<_Tp1() == _Tp2()>;
   //! \return a true-valued Integral Constant if _Tp1 is less than _Tp2.
   template <typename _Tp1, typename _Tp2>   using comp_lt = bool_<(_Tp1() < _Tp2())>;

   //! Not equal
   template <typename _Tp1, typename _Tp2>   using comp_ne = not_<comp_eq<_Tp1, _Tp2>>;
   //! Greater than
   template <typename _Tp1, typename _Tp2>   using comp_gt = comp_lt <_Tp2, _Tp1>;
   //! Less or equal
   template <typename _Tp1, typename _Tp2>   using comp_le = not_<comp_lt<_Tp2, _Tp1>>;
   //! Greater or equal
   template <typename _Tp1, typename _Tp2>   using comp_ge = not_<comp_lt<_Tp1, _Tp2>>;
  //! @}

   /*!
    * Bitwise operations
    * requires IntegralConstant(_Tp)
    */
   //! @{

   //! \return bitwise not (~) operation of its argument.
   template <typename _T>  using bitnot_ = integral_c<typename _T::value_type, (typename _T::value_type)(~_T())>;
   //! \return bitwise and (&) operation of its arguments
   template <typename _Tp1, typename _Tp2>
   using bitand_ = integral_c<decltype(_Tp1() & _Tp2()), _Tp1() & _Tp2()>;
   //! \return bitwise or (|) operation of its arguments.
   template <typename _Tp1, typename _Tp2>
   using bitor_ = integral_c<decltype(_Tp1() | _Tp2()), _Tp1() | _Tp2()>;

   //! \return bitwise xor (^) operation of its arguments.
   template <typename _Tp1, typename _Tp2>
   using bitxor_ = integral_c<decltype(_Tp1() ^ _Tp2()), _Tp1() ^ _Tp2()>;
   //! \return the result of bitwise shift left (<<) operation on _Tp.
   template <typename _Tp, typename shift>
   using shift_left = integral_c<typename _Tp::value_type, (typename _Tp::value_type)(_Tp() << shift())>;
   //! \return the result of bitwise shift right (>>) operation on _Tp.
   template <typename _Tp, typename shift>
   using shift_right = integral_c<typename _Tp::value_type, (typename _Tp::value_type)(_Tp() >> shift())>;
   //! @}
}}
//!@}

#endif /* __utl_meta_integral_h__ */