1 // (c) Copyright Fernando Luis Cacciola Carballal 2000-2004 2 // Use, modification, and distribution is subject to the Boost Software 3 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at 4 // http://www.boost.org/LICENSE_1_0.txt) 5 6 // See library home page at http://www.boost.org/libs/numeric/conversion 7 // 8 // Contact the author at: fernando_cacciola@hotmail.com 9 // 10 #ifndef BOOST_NUMERIC_CONVERSION_DETAIL_SIGN_MIXTURE_FLC_12NOV2002_HPP 11 #define BOOST_NUMERIC_CONVERSION_DETAIL_SIGN_MIXTURE_FLC_12NOV2002_HPP 12 13 #include "boost/config.hpp" 14 #include "boost/limits.hpp" 15 16 #include "boost/numeric/conversion/sign_mixture_enum.hpp" 17 #include "boost/numeric/conversion/detail/meta.hpp" 18 19 #include "boost/mpl/integral_c.hpp" 20 21 namespace boost { namespace numeric { namespace convdetail 22 { 23 // Integral Constants for 'SignMixture' 24 typedef mpl::integral_c<sign_mixture_enum, unsigned_to_unsigned> unsig2unsig_c ; 25 typedef mpl::integral_c<sign_mixture_enum, signed_to_signed> sig2sig_c ; 26 typedef mpl::integral_c<sign_mixture_enum, signed_to_unsigned> sig2unsig_c ; 27 typedef mpl::integral_c<sign_mixture_enum, unsigned_to_signed> unsig2sig_c ; 28 29 // Metafunction: 30 // 31 // get_sign_mixture<T,S>::type 32 // 33 // Selects the appropriate SignMixture Integral Constant for the combination T,S. 34 // 35 template<class T,class S> 36 struct get_sign_mixture 37 { 38 typedef mpl::bool_< ::std::numeric_limits<S>::is_signed > S_signed ; 39 typedef mpl::bool_< ::std::numeric_limits<T>::is_signed > T_signed ; 40 41 typedef typename 42 for_both<S_signed, T_signed, sig2sig_c, sig2unsig_c, unsig2sig_c, unsig2unsig_c>::type 43 type ; 44 } ; 45 46 // Metafunction: 47 // 48 // for_sign_mixture<SignMixture,Sig2Sig,Sig2Unsig,Unsig2Sig,Unsig2Unsig>::type 49 // 50 // {SignMixture} is one of the Integral Constants for SignMixture, declared above. 51 // {Sig2Sig,Sig2Unsig,Unsig2Sig,Unsig2Unsig} are aribtrary types. (not metafunctions) 52 // 53 // According to the value of 'SignMixture', selects the corresponding type. 54 // 55 template<class SignMixture, class Sig2Sig, class Sig2Unsig, class Unsig2Sig, class Unsig2Unsig> 56 struct for_sign_mixture 57 { 58 typedef typename 59 ct_switch4<SignMixture 60 , sig2sig_c, sig2unsig_c, unsig2sig_c // default 61 , Sig2Sig , Sig2Unsig , Unsig2Sig , Unsig2Unsig 62 >::type 63 type ; 64 } ; 65 66 } } } // namespace boost::numeric::convdetail 67 68 #endif 69 // 70 /////////////////////////////////////////////////////////////////////////////////////////////// 71 72 73