//  © Copyright Fernando Luis Cacciola Carballal 2000-2004

//  Use, modification, and distribution is subject to the Boost Software

//  License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

//  http://www.boost.org/LICENSE_1_0.txt)

//  See library home page at http://www.boost.org/libs/numeric/conversion

//

// Contact the author at: fernando_cacciola@hotmail.com

// 

#ifndef BOOST_NUMERIC_CONVERSION_DETAIL_SIGN_MIXTURE_FLC_12NOV2002_HPP

#define BOOST_NUMERIC_CONVERSION_DETAIL_SIGN_MIXTURE_FLC_12NOV2002_HPP

#include "boost/config.hpp"

#include "boost/limits.hpp"

#include "boost/numeric/conversion/sign_mixture_enum.hpp"

#include "boost/numeric/conversion/detail/meta.hpp"

#include "boost/mpl/integral_c.hpp"

namespace boost { namespace numeric { namespace convdetail

{

  // Integral Constants for 'SignMixture'

  typedef mpl::integral_c<sign_mixture_enum, unsigned_to_unsigned> unsig2unsig_c ;

  typedef mpl::integral_c<sign_mixture_enum, signed_to_signed>     sig2sig_c ;

  typedef mpl::integral_c<sign_mixture_enum, signed_to_unsigned>   sig2unsig_c ;

  typedef mpl::integral_c<sign_mixture_enum, unsigned_to_signed>   unsig2sig_c ;

  // Metafunction:

  //

  //   get_sign_mixture<T,S>::type

  //

  // Selects the appropriate SignMixture Integral Constant for the combination T,S.

  //

  template<class T,class S>

  struct get_sign_mixture

  {

    typedef mpl::bool_< ::std::numeric_limits<S>::is_signed > S_signed ;

    typedef mpl::bool_< ::std::numeric_limits<T>::is_signed > T_signed ;

    typedef typename

      for_both<S_signed, T_signed, sig2sig_c, sig2unsig_c, unsig2sig_c, unsig2unsig_c>::type

        type ;

  } ;

  // Metafunction:

  //

  //   for_sign_mixture<SignMixture,Sig2Sig,Sig2Unsig,Unsig2Sig,Unsig2Unsig>::type

  //

  // {SignMixture} is one of the Integral Constants for SignMixture, declared above.

  // {Sig2Sig,Sig2Unsig,Unsig2Sig,Unsig2Unsig} are aribtrary types. (not metafunctions)

  //

  // According to the value of 'SignMixture', selects the corresponding type.

  //

  template<class SignMixture, class Sig2Sig, class Sig2Unsig, class Unsig2Sig, class Unsig2Unsig>

  struct for_sign_mixture

  {

    typedef typename

      ct_switch4<SignMixture

                 , sig2sig_c, sig2unsig_c, unsig2sig_c  // default

                 , Sig2Sig  , Sig2Unsig  , Unsig2Sig  , Unsig2Unsig

                >::type

        type ;

  } ;

} } } // namespace boost::numeric::convdetail

#endif

//

///////////////////////////////////////////////////////////////////////////////////////////////