williamr@2: //  © Copyright Fernando Luis Cacciola Carballal 2000-2004
williamr@2: //  Use, modification, and distribution is subject to the Boost Software
williamr@2: //  License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
williamr@2: //  http://www.boost.org/LICENSE_1_0.txt)
williamr@2: 
williamr@2: //  See library home page at http://www.boost.org/libs/numeric/conversion
williamr@2: //
williamr@2: // Contact the author at: fernando_cacciola@hotmail.com
williamr@2: //
williamr@2: #ifndef BOOST_NUMERIC_CONVERSION_DETAIL_CONVERTER_FLC_12NOV2002_HPP
williamr@2: #define BOOST_NUMERIC_CONVERSION_DETAIL_CONVERTER_FLC_12NOV2002_HPP
williamr@2: 
williamr@2: #include <functional>
williamr@2: 
williamr@2: #include "boost/numeric/conversion/detail/meta.hpp"
williamr@2: #include "boost/numeric/conversion/detail/conversion_traits.hpp"
williamr@2: #include "boost/numeric/conversion/bounds.hpp"
williamr@2: 
williamr@2: #include "boost/type_traits/is_same.hpp"
williamr@2: 
williamr@2: #include "boost/mpl/integral_c.hpp"
williamr@2: 
williamr@2: namespace boost { namespace numeric { namespace convdetail
williamr@2: {
williamr@2:   // Integral Constants representing rounding modes
williamr@2:   typedef mpl::integral_c<std::float_round_style, std::round_toward_zero>         round2zero_c ;
williamr@2:   typedef mpl::integral_c<std::float_round_style, std::round_to_nearest>          round2nearest_c ;
williamr@2:   typedef mpl::integral_c<std::float_round_style, std::round_toward_infinity>     round2inf_c ;
williamr@2:   typedef mpl::integral_c<std::float_round_style, std::round_toward_neg_infinity> round2neg_inf_c ;
williamr@2: 
williamr@2:   // Metafunction:
williamr@2:   //
williamr@2:   //   for_round_style<RoundStyle,RoundToZero,RoundToNearest,RoundToInf,RoundToNegInf>::type
williamr@2:   //
williamr@2:   // {RoundStyle} Integral Constant specifying a round style as declared above.
williamr@2:   // {RoundToZero,RoundToNearest,RoundToInf,RoundToNegInf} arbitrary types.
williamr@2:   //
williamr@2:   // Selects one of the 4 types according to the value of RoundStyle.
williamr@2:   //
williamr@2:   template<class RoundStyle,class RoundToZero,class RoundToNearest,class RoundToInf,class RoundToNegInf>
williamr@2:   struct for_round_style
williamr@2:   {
williamr@2:     typedef ct_switch4<RoundStyle
williamr@2:                        , round2zero_c, round2nearest_c, round2inf_c // round2neg_inf_c
williamr@2:                        , RoundToZero , RoundToNearest , RoundToInf , RoundToNegInf
williamr@2:                       > selector ;
williamr@2: 
williamr@2:     typedef typename selector::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: //--------------------------------------------------------------------------
williamr@2: //                             Range Checking Logic.
williamr@2: //
williamr@2: // The range checking logic is built up by combining 1 or 2 predicates.
williamr@2: // Each predicate is encapsulated in a template class and exposes
williamr@2: // the static member function 'apply'.
williamr@2: //
williamr@2: //--------------------------------------------------------------------------
williamr@2: 
williamr@2: 
williamr@2:   // Because a particular logic can combine either 1 or two predicates, the following
williamr@2:   // tags are used to allow the predicate applier to receive 2 preds, but optimize away
williamr@2:   // one of them if it is 'non-applicable'
williamr@2:   struct non_applicable { typedef mpl::false_ do_apply ; } ;
williamr@2:   struct applicable     { typedef mpl::true_  do_apply ; } ;
williamr@2: 
williamr@2: 
williamr@2:   //--------------------------------------------------------------------------
williamr@2:   //
williamr@2:   //                      Range Checking Logic implementations.
williamr@2:   //
williamr@2:   // The following classes, collectivelly named 'Predicates', are instantiated within
williamr@2:   // the corresponding range checkers.
williamr@2:   // Their static member function 'apply' is called to perform the actual range checking logic.
williamr@2:   //--------------------------------------------------------------------------
williamr@2: 
williamr@2:     // s < Lowest(T) ? cNegOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct LT_LoT : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::target_type T ;
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s < static_cast<S>(bounds<T>::lowest()) ? cNegOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     // s < 0 ? cNegOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct LT_Zero : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s < static_cast<S>(0) ? cNegOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     // s <= Lowest(T)-1 ? cNegOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct LE_PrevLoT : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::target_type T ;
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s <= static_cast<S>(bounds<T>::lowest()) - static_cast<S>(1.0)
williamr@2:                  ? cNegOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     // s < Lowest(T)-0.5 ? cNegOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct LT_HalfPrevLoT : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::target_type T ;
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s < static_cast<S>(bounds<T>::lowest()) - static_cast<S>(0.5)
williamr@2:                  ? cNegOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     // s > Highest(T) ? cPosOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct GT_HiT : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::target_type T ;
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s > static_cast<S>(bounds<T>::highest())
williamr@2:                  ? cPosOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     // s >= Lowest(T) + 1 ? cPosOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct GE_SuccHiT : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::target_type T ;
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s >= static_cast<S>(bounds<T>::highest()) + static_cast<S>(1.0)
williamr@2:                  ? cPosOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     // s >= Lowest(T) + 0.5 ? cPosgOverflow : cInRange
williamr@2:     //
williamr@2:     template<class Traits>
williamr@2:     struct GT_HalfSuccHiT : applicable
williamr@2:     {
williamr@2:       typedef typename Traits::target_type T ;
williamr@2:       typedef typename Traits::source_type S ;
williamr@2:       typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         return s >= static_cast<S>(bounds<T>::highest()) + static_cast<S>(0.5)
williamr@2:                  ? cPosOverflow : cInRange ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2: 
williamr@2:   //--------------------------------------------------------------------------
williamr@2:   //
williamr@2:   // Predicate Combiner.
williamr@2:   //
williamr@2:   // This helper classes are used to possibly combine the range checking logic
williamr@2:   // individually performed by the predicates
williamr@2:   //
williamr@2:   //--------------------------------------------------------------------------
williamr@2: 
williamr@2: 
williamr@2:     // Applies both predicates: first 'PredA', and if it equals 'cInRange', 'PredB'
williamr@2:     template<class PredA, class PredB>
williamr@2:     struct applyBoth
williamr@2:     {
williamr@2:       typedef typename PredA::argument_type argument_type ;
williamr@2: 
williamr@2:       static range_check_result apply ( argument_type s )
williamr@2:       {
williamr@2:         range_check_result r = PredA::apply(s) ;
williamr@2:         if ( r == cInRange )
williamr@2:           r = PredB::apply(s);
williamr@2:         return r ;
williamr@2:       }
williamr@2:     } ;
williamr@2: 
williamr@2:     template<class PredA, class PredB>
williamr@2:     struct combine
williamr@2:     {
williamr@2:       typedef applyBoth<PredA,PredB> Both ;
williamr@2:       typedef void                   NNone ; // 'None' is defined as a macro in (/usr/X11R6/include/X11/X.h)
williamr@2: 
williamr@2:       typedef typename PredA::do_apply do_applyA ;
williamr@2:       typedef typename PredB::do_apply do_applyB ;
williamr@2: 
williamr@2:       typedef typename for_both<do_applyA, do_applyB, Both, PredA, PredB, NNone>::type type ;
williamr@2:     } ;
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: //--------------------------------------------------------------------------
williamr@2: //                             Range Checker classes.
williamr@2: //
williamr@2: // The following classes are VISIBLE base classes of the user-level converter<> class.
williamr@2: // They supply the optimized 'out_of_range()' and 'validate_range()' static member functions
williamr@2: // visible in the user interface.
williamr@2: //
williamr@2: //--------------------------------------------------------------------------
williamr@2: 
williamr@2:   // Dummy range checker.
williamr@2:   template<class Traits>
williamr@2:   struct dummy_range_checker
williamr@2:   {
williamr@2:     typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:     static range_check_result out_of_range ( argument_type ) { return cInRange ; }
williamr@2:     static void validate_range ( argument_type ) {}
williamr@2:   } ;
williamr@2: 
williamr@2:   // Generic range checker.
williamr@2:   //
williamr@2:   // All the range checking logic for all possible combinations of source and target
williamr@2:   // can be arranged in terms of one or two predicates, which test overflow on both neg/pos 'sides'
williamr@2:   // of the ranges.
williamr@2:   //
williamr@2:   // These predicates are given here as IsNegOverflow and IsPosOverflow.
williamr@2:   //
williamr@2:   template<class Traits, class IsNegOverflow, class IsPosOverflow, class OverflowHandler>
williamr@2:   struct generic_range_checker
williamr@2:   {
williamr@2:     typedef OverflowHandler overflow_handler ;
williamr@2: 
williamr@2:     typedef typename Traits::argument_type argument_type ;
williamr@2: 
williamr@2:     static range_check_result out_of_range ( argument_type s )
williamr@2:     {
williamr@2:       typedef typename combine<IsNegOverflow,IsPosOverflow>::type Predicate ;
williamr@2: 
williamr@2:       return Predicate::apply(s);
williamr@2:     }
williamr@2: 
williamr@2:     static void validate_range ( argument_type s )
williamr@2:       { OverflowHandler()( out_of_range(s) ) ; }
williamr@2:   } ;
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: //--------------------------------------------------------------------------
williamr@2: //
williamr@2: // Selectors for the optimized Range Checker class.
williamr@2: //
williamr@2: //--------------------------------------------------------------------------
williamr@2: 
williamr@2:   template<class Traits,class OverflowHandler>
williamr@2:   struct GetRC_Sig2Sig_or_Unsig2Unsig
williamr@2:   {
williamr@2:     typedef dummy_range_checker<Traits> Dummy ;
williamr@2: 
williamr@2:     typedef LT_LoT<Traits> Pred1 ;
williamr@2:     typedef GT_HiT<Traits> Pred2 ;
williamr@2: 
williamr@2:     typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> Normal ;
williamr@2: 
williamr@2:     typedef typename Traits::subranged subranged ;
williamr@2: 
williamr@2:     typedef typename mpl::if_<subranged,Normal,Dummy>::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits, class OverflowHandler>
williamr@2:   struct GetRC_Sig2Unsig
williamr@2:   {
williamr@2:     typedef LT_Zero<Traits> Pred1 ;
williamr@2:     typedef GT_HiT <Traits> Pred2 ;
williamr@2: 
williamr@2:     typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> ChoiceA ;
williamr@2: 
williamr@2:     typedef generic_range_checker<Traits,Pred1,non_applicable,OverflowHandler> ChoiceB ;
williamr@2: 
williamr@2:     typedef typename Traits::target_type T ;
williamr@2:     typedef typename Traits::source_type S ;
williamr@2: 
williamr@2:     typedef typename subranged_Unsig2Sig<S,T>::type oposite_subranged ;
williamr@2: 
williamr@2:     typedef typename mpl::not_<oposite_subranged>::type positively_subranged ;
williamr@2: 
williamr@2:     typedef typename mpl::if_<positively_subranged,ChoiceA,ChoiceB>::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits, class OverflowHandler>
williamr@2:   struct GetRC_Unsig2Sig
williamr@2:   {
williamr@2:     typedef GT_HiT<Traits> Pred1 ;
williamr@2: 
williamr@2:     typedef generic_range_checker<Traits,non_applicable,Pred1,OverflowHandler> type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits,class OverflowHandler>
williamr@2:   struct GetRC_Int2Int
williamr@2:   {
williamr@2:     typedef GetRC_Sig2Sig_or_Unsig2Unsig<Traits,OverflowHandler> Sig2SigQ     ;
williamr@2:     typedef GetRC_Sig2Unsig             <Traits,OverflowHandler> Sig2UnsigQ   ;
williamr@2:     typedef GetRC_Unsig2Sig             <Traits,OverflowHandler> Unsig2SigQ   ;
williamr@2:     typedef Sig2SigQ                                             Unsig2UnsigQ ;
williamr@2: 
williamr@2:     typedef typename Traits::sign_mixture sign_mixture ;
williamr@2: 
williamr@2:     typedef typename
williamr@2:       for_sign_mixture<sign_mixture,Sig2SigQ,Sig2UnsigQ,Unsig2SigQ,Unsig2UnsigQ>::type
williamr@2:         selector ;
williamr@2: 
williamr@2:     typedef typename selector::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits>
williamr@2:   struct GetRC_Int2Float
williamr@2:   {
williamr@2:     typedef dummy_range_checker<Traits> type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits, class OverflowHandler, class Float2IntRounder>
williamr@2:   struct GetRC_Float2Int
williamr@2:   {
williamr@2:     typedef LE_PrevLoT    <Traits> Pred1 ;
williamr@2:     typedef GE_SuccHiT    <Traits> Pred2 ;
williamr@2:     typedef LT_HalfPrevLoT<Traits> Pred3 ;
williamr@2:     typedef GT_HalfSuccHiT<Traits> Pred4 ;
williamr@2:     typedef GT_HiT        <Traits> Pred5 ;
williamr@2:     typedef LT_LoT        <Traits> Pred6 ;
williamr@2: 
williamr@2:     typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> ToZero    ;
williamr@2:     typedef generic_range_checker<Traits,Pred3,Pred4,OverflowHandler> ToNearest ;
williamr@2:     typedef generic_range_checker<Traits,Pred1,Pred5,OverflowHandler> ToInf     ;
williamr@2:     typedef generic_range_checker<Traits,Pred6,Pred2,OverflowHandler> ToNegInf  ;
williamr@2: 
williamr@2:     typedef typename Float2IntRounder::round_style round_style ;
williamr@2: 
williamr@2:     typedef typename for_round_style<round_style,ToZero,ToNearest,ToInf,ToNegInf>::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits, class OverflowHandler>
williamr@2:   struct GetRC_Float2Float
williamr@2:   {
williamr@2:     typedef dummy_range_checker<Traits> Dummy ;
williamr@2: 
williamr@2:     typedef LT_LoT<Traits> Pred1 ;
williamr@2:     typedef GT_HiT<Traits> Pred2 ;
williamr@2: 
williamr@2:     typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> Normal ;
williamr@2: 
williamr@2:     typedef typename Traits::subranged subranged ;
williamr@2: 
williamr@2:     typedef typename mpl::if_<subranged,Normal,Dummy>::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits, class OverflowHandler, class Float2IntRounder>
williamr@2:   struct GetRC_BuiltIn2BuiltIn
williamr@2:   {
williamr@2:     typedef GetRC_Int2Int<Traits,OverflowHandler>                    Int2IntQ ;
williamr@2:     typedef GetRC_Int2Float<Traits>                                  Int2FloatQ ;
williamr@2:     typedef GetRC_Float2Int<Traits,OverflowHandler,Float2IntRounder> Float2IntQ ;
williamr@2:     typedef GetRC_Float2Float<Traits,OverflowHandler>                Float2FloatQ ;
williamr@2: 
williamr@2:     typedef typename Traits::int_float_mixture int_float_mixture ;
williamr@2: 
williamr@2:     typedef typename for_int_float_mixture<int_float_mixture, Int2IntQ, Int2FloatQ, Float2IntQ, Float2FloatQ>::type selector ;
williamr@2: 
williamr@2:     typedef typename selector::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template<class Traits, class OverflowHandler, class Float2IntRounder>
williamr@2:   struct GetRC
williamr@2:   {
williamr@2:     typedef GetRC_BuiltIn2BuiltIn<Traits,OverflowHandler,Float2IntRounder> BuiltIn2BuiltInQ ;
williamr@2: 
williamr@2:     typedef dummy_range_checker<Traits> Dummy ;
williamr@2: 
williamr@2:     typedef mpl::identity<Dummy> DummyQ ;
williamr@2: 
williamr@2:     typedef typename Traits::udt_builtin_mixture udt_builtin_mixture ;
williamr@2: 
williamr@2:     typedef typename for_udt_builtin_mixture<udt_builtin_mixture,BuiltIn2BuiltInQ,DummyQ,DummyQ,DummyQ>::type selector ;
williamr@2: 
williamr@2:     typedef typename selector::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: //--------------------------------------------------------------------------
williamr@2: //                             Converter classes.
williamr@2: //
williamr@2: // The following classes are VISIBLE base classes of the user-level converter<> class.
williamr@2: // They supply the optimized 'nearbyint()' and 'convert()' static member functions
williamr@2: // visible in the user interface.
williamr@2: //
williamr@2: //--------------------------------------------------------------------------
williamr@2: 
williamr@2:   //
williamr@2:   // Trivial Converter : used when (cv-unqualified) T == (cv-unqualified)  S
williamr@2:   //
williamr@2:   template<class Traits>
williamr@2:   struct trivial_converter_impl : public std::unary_function<  BOOST_DEDUCED_TYPENAME Traits::argument_type
williamr@2:                                                               ,BOOST_DEDUCED_TYPENAME Traits::result_type
williamr@2:                                                             >
williamr@2:                                  ,public dummy_range_checker<Traits>
williamr@2:   {
williamr@2:     typedef Traits traits ;
williamr@2: 
williamr@2:     typedef typename Traits::source_type   source_type   ;
williamr@2:     typedef typename Traits::argument_type argument_type ;
williamr@2:     typedef typename Traits::result_type   result_type   ;
williamr@2: 
williamr@2:     static result_type low_level_convert ( argument_type s ) { return s ; }
williamr@2:     static source_type nearbyint         ( argument_type s ) { return s ; }
williamr@2:     static result_type convert           ( argument_type s ) { return s ; }
williamr@2:   } ;
williamr@2: 
williamr@2: 
williamr@2:   //
williamr@2:   // Rounding Converter : used for float to integral conversions.
williamr@2:   //
williamr@2:   template<class Traits,class RangeChecker,class RawConverter,class Float2IntRounder>
williamr@2:   struct rounding_converter : public std::unary_function<  BOOST_DEDUCED_TYPENAME Traits::argument_type
williamr@2:                                                           ,BOOST_DEDUCED_TYPENAME Traits::result_type
williamr@2:                                                         >
williamr@2:                              ,public RangeChecker
williamr@2:                              ,public Float2IntRounder
williamr@2:                              ,public RawConverter
williamr@2:   {
williamr@2:     typedef RangeChecker     RangeCheckerBase ;
williamr@2:     typedef Float2IntRounder Float2IntRounderBase ;
williamr@2:     typedef RawConverter     RawConverterBase ;
williamr@2: 
williamr@2:     typedef Traits traits ;
williamr@2: 
williamr@2:     typedef typename Traits::source_type   source_type   ;
williamr@2:     typedef typename Traits::argument_type argument_type ;
williamr@2:     typedef typename Traits::result_type   result_type   ;
williamr@2: 
williamr@2:     static result_type convert ( argument_type s )
williamr@2:     {
williamr@2:       RangeCheckerBase::validate_range(s);
williamr@2:       source_type s1 = Float2IntRounderBase::nearbyint(s);
williamr@2:       return RawConverterBase::low_level_convert(s1);
williamr@2:     }
williamr@2:   } ;
williamr@2: 
williamr@2: 
williamr@2:   //
williamr@2:   // Non-Rounding Converter : used for all other conversions.
williamr@2:   //
williamr@2:   template<class Traits,class RangeChecker,class RawConverter>
williamr@2:   struct non_rounding_converter : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type
williamr@2:                                                              ,BOOST_DEDUCED_TYPENAME Traits::result_type
williamr@2:                                                            >
williamr@2:                                  ,public RangeChecker
williamr@2:                                  ,public RawConverter
williamr@2:   {
williamr@2:     typedef RangeChecker RangeCheckerBase ;
williamr@2:     typedef RawConverter RawConverterBase ;
williamr@2: 
williamr@2:     typedef Traits traits ;
williamr@2: 
williamr@2:     typedef typename Traits::source_type   source_type   ;
williamr@2:     typedef typename Traits::argument_type argument_type ;
williamr@2:     typedef typename Traits::result_type   result_type   ;
williamr@2: 
williamr@2:     static source_type nearbyint ( argument_type s ) { return s ; }
williamr@2: 
williamr@2:     static result_type convert ( argument_type s )
williamr@2:     {
williamr@2:       RangeCheckerBase::validate_range(s);
williamr@2:       return RawConverterBase::low_level_convert(s);
williamr@2:     }
williamr@2:   } ;
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: 
williamr@2: //--------------------------------------------------------------------------
williamr@2: //
williamr@2: // Selectors for the optimized Converter class.
williamr@2: //
williamr@2: //--------------------------------------------------------------------------
williamr@2: 
williamr@2:   template<class Traits,class OverflowHandler,class Float2IntRounder,class RawConverter, class UserRangeChecker>
williamr@2:   struct get_non_trivial_converter
williamr@2:   {
williamr@2:     typedef GetRC<Traits,OverflowHandler,Float2IntRounder> InternalRangeCheckerQ ;
williamr@2: 
williamr@2:     typedef is_same<UserRangeChecker,UseInternalRangeChecker> use_internal_RC ;
williamr@2: 
williamr@2:     typedef mpl::identity<UserRangeChecker> UserRangeCheckerQ ;
williamr@2: 
williamr@2:     typedef typename
williamr@2:       mpl::eval_if<use_internal_RC,InternalRangeCheckerQ,UserRangeCheckerQ>::type
williamr@2:         RangeChecker ;
williamr@2: 
williamr@2:     typedef non_rounding_converter<Traits,RangeChecker,RawConverter>              NonRounding ;
williamr@2:     typedef rounding_converter<Traits,RangeChecker,RawConverter,Float2IntRounder> Rounding ;
williamr@2: 
williamr@2:     typedef mpl::identity<NonRounding> NonRoundingQ ;
williamr@2:     typedef mpl::identity<Rounding>    RoundingQ    ;
williamr@2: 
williamr@2:     typedef typename Traits::int_float_mixture int_float_mixture ;
williamr@2: 
williamr@2:     typedef typename
williamr@2:       for_int_float_mixture<int_float_mixture, NonRoundingQ, NonRoundingQ, RoundingQ, NonRoundingQ>::type
williamr@2:         selector ;
williamr@2: 
williamr@2:     typedef typename selector::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2:   template< class Traits
williamr@2:            ,class OverflowHandler
williamr@2:            ,class Float2IntRounder
williamr@2:            ,class RawConverter
williamr@2:            ,class UserRangeChecker
williamr@2:           >
williamr@2:   struct get_converter_impl
williamr@2:   {
williamr@2: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT( 0x0561 ) )
williamr@2:     // bcc55 prefers sometimes template parameters to be explicit local types.
williamr@2:     // (notice that is is illegal to reuse the names like this)
williamr@2:     typedef Traits           Traits ;
williamr@2:     typedef OverflowHandler  OverflowHandler ;
williamr@2:     typedef Float2IntRounder Float2IntRounder ;
williamr@2:     typedef RawConverter     RawConverter ;
williamr@2:     typedef UserRangeChecker UserRangeChecker ;
williamr@2: #endif
williamr@2: 
williamr@2:     typedef trivial_converter_impl<Traits> Trivial ;
williamr@2:     typedef mpl::identity        <Trivial> TrivialQ ;
williamr@2: 
williamr@2:     typedef get_non_trivial_converter< Traits
williamr@2:                                       ,OverflowHandler
williamr@2:                                       ,Float2IntRounder
williamr@2:                                       ,RawConverter
williamr@2:                                       ,UserRangeChecker
williamr@2:                                      > NonTrivialQ ;
williamr@2: 
williamr@2:     typedef typename Traits::trivial trivial ;
williamr@2: 
williamr@2:     typedef typename mpl::eval_if<trivial,TrivialQ,NonTrivialQ>::type type ;
williamr@2:   } ;
williamr@2: 
williamr@2: } } } // namespace boost::numeric::convdetail
williamr@2: 
williamr@2: #endif
williamr@2: 
williamr@2: