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Diffstat (limited to '3rdParty/Boost/boost/numeric/conversion/detail/converter.hpp')
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1 files changed, 602 insertions, 0 deletions
diff --git a/3rdParty/Boost/boost/numeric/conversion/detail/converter.hpp b/3rdParty/Boost/boost/numeric/conversion/detail/converter.hpp new file mode 100644 index 0000000..10550f8 --- /dev/null +++ b/3rdParty/Boost/boost/numeric/conversion/detail/converter.hpp @@ -0,0 +1,602 @@ +// (c) 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_CONVERTER_FLC_12NOV2002_HPP +#define BOOST_NUMERIC_CONVERSION_DETAIL_CONVERTER_FLC_12NOV2002_HPP + +#include <functional> + +#include "boost/numeric/conversion/detail/meta.hpp" +#include "boost/numeric/conversion/detail/conversion_traits.hpp" +#include "boost/numeric/conversion/bounds.hpp" + +#include "boost/type_traits/is_same.hpp" + +#include "boost/mpl/integral_c.hpp" + +namespace boost { namespace numeric { namespace convdetail +{ + // Integral Constants representing rounding modes + typedef mpl::integral_c<std::float_round_style, std::round_toward_zero> round2zero_c ; + typedef mpl::integral_c<std::float_round_style, std::round_to_nearest> round2nearest_c ; + typedef mpl::integral_c<std::float_round_style, std::round_toward_infinity> round2inf_c ; + typedef mpl::integral_c<std::float_round_style, std::round_toward_neg_infinity> round2neg_inf_c ; + + // Metafunction: + // + // for_round_style<RoundStyle,RoundToZero,RoundToNearest,RoundToInf,RoundToNegInf>::type + // + // {RoundStyle} Integral Constant specifying a round style as declared above. + // {RoundToZero,RoundToNearest,RoundToInf,RoundToNegInf} arbitrary types. + // + // Selects one of the 4 types according to the value of RoundStyle. + // + template<class RoundStyle,class RoundToZero,class RoundToNearest,class RoundToInf,class RoundToNegInf> + struct for_round_style + { + typedef ct_switch4<RoundStyle + , round2zero_c, round2nearest_c, round2inf_c // round2neg_inf_c + , RoundToZero , RoundToNearest , RoundToInf , RoundToNegInf + > selector ; + + typedef typename selector::type type ; + } ; + + + + + + + + + + + + + + + + + + +//-------------------------------------------------------------------------- +// Range Checking Logic. +// +// The range checking logic is built up by combining 1 or 2 predicates. +// Each predicate is encapsulated in a template class and exposes +// the static member function 'apply'. +// +//-------------------------------------------------------------------------- + + + // Because a particular logic can combine either 1 or two predicates, the following + // tags are used to allow the predicate applier to receive 2 preds, but optimize away + // one of them if it is 'non-applicable' + struct non_applicable { typedef mpl::false_ do_apply ; } ; + struct applicable { typedef mpl::true_ do_apply ; } ; + + + //-------------------------------------------------------------------------- + // + // Range Checking Logic implementations. + // + // The following classes, collectivelly named 'Predicates', are instantiated within + // the corresponding range checkers. + // Their static member function 'apply' is called to perform the actual range checking logic. + //-------------------------------------------------------------------------- + + // s < Lowest(T) ? cNegOverflow : cInRange + // + template<class Traits> + struct LT_LoT : applicable + { + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s < static_cast<S>(bounds<T>::lowest()) ? cNegOverflow : cInRange ; + } + } ; + + // s < 0 ? cNegOverflow : cInRange + // + template<class Traits> + struct LT_Zero : applicable + { + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s < static_cast<S>(0) ? cNegOverflow : cInRange ; + } + } ; + + // s <= Lowest(T)-1 ? cNegOverflow : cInRange + // + template<class Traits> + struct LE_PrevLoT : applicable + { + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s <= static_cast<S>(bounds<T>::lowest()) - static_cast<S>(1.0) + ? cNegOverflow : cInRange ; + } + } ; + + // s < Lowest(T)-0.5 ? cNegOverflow : cInRange + // + template<class Traits> + struct LT_HalfPrevLoT : applicable + { + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s < static_cast<S>(bounds<T>::lowest()) - static_cast<S>(0.5) + ? cNegOverflow : cInRange ; + } + } ; + + // s > Highest(T) ? cPosOverflow : cInRange + // + template<class Traits> + struct GT_HiT : applicable + { + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s > static_cast<S>(bounds<T>::highest()) + ? cPosOverflow : cInRange ; + } + } ; + + // s >= Lowest(T) + 1 ? cPosOverflow : cInRange + // + template<class Traits> + struct GE_SuccHiT : applicable + { + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s >= static_cast<S>(bounds<T>::highest()) + static_cast<S>(1.0) + ? cPosOverflow : cInRange ; + } + } ; + + // s >= Lowest(T) + 0.5 ? cPosgOverflow : cInRange + // + template<class Traits> + struct GT_HalfSuccHiT : applicable + { + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + typedef typename Traits::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + return s >= static_cast<S>(bounds<T>::highest()) + static_cast<S>(0.5) + ? cPosOverflow : cInRange ; + } + } ; + + + //-------------------------------------------------------------------------- + // + // Predicate Combiner. + // + // This helper classes are used to possibly combine the range checking logic + // individually performed by the predicates + // + //-------------------------------------------------------------------------- + + + // Applies both predicates: first 'PredA', and if it equals 'cInRange', 'PredB' + template<class PredA, class PredB> + struct applyBoth + { + typedef typename PredA::argument_type argument_type ; + + static range_check_result apply ( argument_type s ) + { + range_check_result r = PredA::apply(s) ; + if ( r == cInRange ) + r = PredB::apply(s); + return r ; + } + } ; + + template<class PredA, class PredB> + struct combine + { + typedef applyBoth<PredA,PredB> Both ; + typedef void NNone ; // 'None' is defined as a macro in (/usr/X11R6/include/X11/X.h) + + typedef typename PredA::do_apply do_applyA ; + typedef typename PredB::do_apply do_applyB ; + + typedef typename for_both<do_applyA, do_applyB, Both, PredA, PredB, NNone>::type type ; + } ; + + + + + + + + + + + + +//-------------------------------------------------------------------------- +// Range Checker classes. +// +// The following classes are VISIBLE base classes of the user-level converter<> class. +// They supply the optimized 'out_of_range()' and 'validate_range()' static member functions +// visible in the user interface. +// +//-------------------------------------------------------------------------- + + // Dummy range checker. + template<class Traits> + struct dummy_range_checker + { + typedef typename Traits::argument_type argument_type ; + + static range_check_result out_of_range ( argument_type ) { return cInRange ; } + static void validate_range ( argument_type ) {} + } ; + + // Generic range checker. + // + // All the range checking logic for all possible combinations of source and target + // can be arranged in terms of one or two predicates, which test overflow on both neg/pos 'sides' + // of the ranges. + // + // These predicates are given here as IsNegOverflow and IsPosOverflow. + // + template<class Traits, class IsNegOverflow, class IsPosOverflow, class OverflowHandler> + struct generic_range_checker + { + typedef OverflowHandler overflow_handler ; + + typedef typename Traits::argument_type argument_type ; + + static range_check_result out_of_range ( argument_type s ) + { + typedef typename combine<IsNegOverflow,IsPosOverflow>::type Predicate ; + + return Predicate::apply(s); + } + + static void validate_range ( argument_type s ) + { OverflowHandler()( out_of_range(s) ) ; } + } ; + + + +//-------------------------------------------------------------------------- +// +// Selectors for the optimized Range Checker class. +// +//-------------------------------------------------------------------------- + + template<class Traits,class OverflowHandler> + struct GetRC_Sig2Sig_or_Unsig2Unsig + { + typedef dummy_range_checker<Traits> Dummy ; + + typedef LT_LoT<Traits> Pred1 ; + typedef GT_HiT<Traits> Pred2 ; + + typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> Normal ; + + typedef typename Traits::subranged subranged ; + + typedef typename mpl::if_<subranged,Normal,Dummy>::type type ; + } ; + + template<class Traits, class OverflowHandler> + struct GetRC_Sig2Unsig + { + typedef LT_Zero<Traits> Pred1 ; + typedef GT_HiT <Traits> Pred2 ; + + typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> ChoiceA ; + + typedef generic_range_checker<Traits,Pred1,non_applicable,OverflowHandler> ChoiceB ; + + typedef typename Traits::target_type T ; + typedef typename Traits::source_type S ; + + typedef typename subranged_Unsig2Sig<S,T>::type oposite_subranged ; + + typedef typename mpl::not_<oposite_subranged>::type positively_subranged ; + + typedef typename mpl::if_<positively_subranged,ChoiceA,ChoiceB>::type type ; + } ; + + template<class Traits, class OverflowHandler> + struct GetRC_Unsig2Sig + { + typedef GT_HiT<Traits> Pred1 ; + + typedef generic_range_checker<Traits,non_applicable,Pred1,OverflowHandler> type ; + } ; + + template<class Traits,class OverflowHandler> + struct GetRC_Int2Int + { + typedef GetRC_Sig2Sig_or_Unsig2Unsig<Traits,OverflowHandler> Sig2SigQ ; + typedef GetRC_Sig2Unsig <Traits,OverflowHandler> Sig2UnsigQ ; + typedef GetRC_Unsig2Sig <Traits,OverflowHandler> Unsig2SigQ ; + typedef Sig2SigQ Unsig2UnsigQ ; + + typedef typename Traits::sign_mixture sign_mixture ; + + typedef typename + for_sign_mixture<sign_mixture,Sig2SigQ,Sig2UnsigQ,Unsig2SigQ,Unsig2UnsigQ>::type + selector ; + + typedef typename selector::type type ; + } ; + + template<class Traits> + struct GetRC_Int2Float + { + typedef dummy_range_checker<Traits> type ; + } ; + + template<class Traits, class OverflowHandler, class Float2IntRounder> + struct GetRC_Float2Int + { + typedef LE_PrevLoT <Traits> Pred1 ; + typedef GE_SuccHiT <Traits> Pred2 ; + typedef LT_HalfPrevLoT<Traits> Pred3 ; + typedef GT_HalfSuccHiT<Traits> Pred4 ; + typedef GT_HiT <Traits> Pred5 ; + typedef LT_LoT <Traits> Pred6 ; + + typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> ToZero ; + typedef generic_range_checker<Traits,Pred3,Pred4,OverflowHandler> ToNearest ; + typedef generic_range_checker<Traits,Pred1,Pred5,OverflowHandler> ToInf ; + typedef generic_range_checker<Traits,Pred6,Pred2,OverflowHandler> ToNegInf ; + + typedef typename Float2IntRounder::round_style round_style ; + + typedef typename for_round_style<round_style,ToZero,ToNearest,ToInf,ToNegInf>::type type ; + } ; + + template<class Traits, class OverflowHandler> + struct GetRC_Float2Float + { + typedef dummy_range_checker<Traits> Dummy ; + + typedef LT_LoT<Traits> Pred1 ; + typedef GT_HiT<Traits> Pred2 ; + + typedef generic_range_checker<Traits,Pred1,Pred2,OverflowHandler> Normal ; + + typedef typename Traits::subranged subranged ; + + typedef typename mpl::if_<subranged,Normal,Dummy>::type type ; + } ; + + template<class Traits, class OverflowHandler, class Float2IntRounder> + struct GetRC_BuiltIn2BuiltIn + { + typedef GetRC_Int2Int<Traits,OverflowHandler> Int2IntQ ; + typedef GetRC_Int2Float<Traits> Int2FloatQ ; + typedef GetRC_Float2Int<Traits,OverflowHandler,Float2IntRounder> Float2IntQ ; + typedef GetRC_Float2Float<Traits,OverflowHandler> Float2FloatQ ; + + typedef typename Traits::int_float_mixture int_float_mixture ; + + typedef typename for_int_float_mixture<int_float_mixture, Int2IntQ, Int2FloatQ, Float2IntQ, Float2FloatQ>::type selector ; + + typedef typename selector::type type ; + } ; + + template<class Traits, class OverflowHandler, class Float2IntRounder> + struct GetRC + { + typedef GetRC_BuiltIn2BuiltIn<Traits,OverflowHandler,Float2IntRounder> BuiltIn2BuiltInQ ; + + typedef dummy_range_checker<Traits> Dummy ; + + typedef mpl::identity<Dummy> DummyQ ; + + typedef typename Traits::udt_builtin_mixture udt_builtin_mixture ; + + typedef typename for_udt_builtin_mixture<udt_builtin_mixture,BuiltIn2BuiltInQ,DummyQ,DummyQ,DummyQ>::type selector ; + + typedef typename selector::type type ; + } ; + + + + +//-------------------------------------------------------------------------- +// Converter classes. +// +// The following classes are VISIBLE base classes of the user-level converter<> class. +// They supply the optimized 'nearbyint()' and 'convert()' static member functions +// visible in the user interface. +// +//-------------------------------------------------------------------------- + + // + // Trivial Converter : used when (cv-unqualified) T == (cv-unqualified) S + // + template<class Traits> + struct trivial_converter_impl : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type + ,BOOST_DEDUCED_TYPENAME Traits::result_type + > + ,public dummy_range_checker<Traits> + { + typedef Traits traits ; + + typedef typename Traits::source_type source_type ; + typedef typename Traits::argument_type argument_type ; + typedef typename Traits::result_type result_type ; + + static result_type low_level_convert ( argument_type s ) { return s ; } + static source_type nearbyint ( argument_type s ) { return s ; } + static result_type convert ( argument_type s ) { return s ; } + } ; + + + // + // Rounding Converter : used for float to integral conversions. + // + template<class Traits,class RangeChecker,class RawConverter,class Float2IntRounder> + struct rounding_converter : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type + ,BOOST_DEDUCED_TYPENAME Traits::result_type + > + ,public RangeChecker + ,public Float2IntRounder + ,public RawConverter + { + typedef RangeChecker RangeCheckerBase ; + typedef Float2IntRounder Float2IntRounderBase ; + typedef RawConverter RawConverterBase ; + + typedef Traits traits ; + + typedef typename Traits::source_type source_type ; + typedef typename Traits::argument_type argument_type ; + typedef typename Traits::result_type result_type ; + + static result_type convert ( argument_type s ) + { + RangeCheckerBase::validate_range(s); + source_type s1 = Float2IntRounderBase::nearbyint(s); + return RawConverterBase::low_level_convert(s1); + } + } ; + + + // + // Non-Rounding Converter : used for all other conversions. + // + template<class Traits,class RangeChecker,class RawConverter> + struct non_rounding_converter : public std::unary_function< BOOST_DEDUCED_TYPENAME Traits::argument_type + ,BOOST_DEDUCED_TYPENAME Traits::result_type + > + ,public RangeChecker + ,public RawConverter + { + typedef RangeChecker RangeCheckerBase ; + typedef RawConverter RawConverterBase ; + + typedef Traits traits ; + + typedef typename Traits::source_type source_type ; + typedef typename Traits::argument_type argument_type ; + typedef typename Traits::result_type result_type ; + + static source_type nearbyint ( argument_type s ) { return s ; } + + static result_type convert ( argument_type s ) + { + RangeCheckerBase::validate_range(s); + return RawConverterBase::low_level_convert(s); + } + } ; + + + + +//-------------------------------------------------------------------------- +// +// Selectors for the optimized Converter class. +// +//-------------------------------------------------------------------------- + + template<class Traits,class OverflowHandler,class Float2IntRounder,class RawConverter, class UserRangeChecker> + struct get_non_trivial_converter + { + typedef GetRC<Traits,OverflowHandler,Float2IntRounder> InternalRangeCheckerQ ; + + typedef is_same<UserRangeChecker,UseInternalRangeChecker> use_internal_RC ; + + typedef mpl::identity<UserRangeChecker> UserRangeCheckerQ ; + + typedef typename + mpl::eval_if<use_internal_RC,InternalRangeCheckerQ,UserRangeCheckerQ>::type + RangeChecker ; + + typedef non_rounding_converter<Traits,RangeChecker,RawConverter> NonRounding ; + typedef rounding_converter<Traits,RangeChecker,RawConverter,Float2IntRounder> Rounding ; + + typedef mpl::identity<NonRounding> NonRoundingQ ; + typedef mpl::identity<Rounding> RoundingQ ; + + typedef typename Traits::int_float_mixture int_float_mixture ; + + typedef typename + for_int_float_mixture<int_float_mixture, NonRoundingQ, NonRoundingQ, RoundingQ, NonRoundingQ>::type + selector ; + + typedef typename selector::type type ; + } ; + + template< class Traits + ,class OverflowHandler + ,class Float2IntRounder + ,class RawConverter + ,class UserRangeChecker + > + struct get_converter_impl + { +#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT( 0x0561 ) ) + // bcc55 prefers sometimes template parameters to be explicit local types. + // (notice that is is illegal to reuse the names like this) + typedef Traits Traits ; + typedef OverflowHandler OverflowHandler ; + typedef Float2IntRounder Float2IntRounder ; + typedef RawConverter RawConverter ; + typedef UserRangeChecker UserRangeChecker ; +#endif + + typedef trivial_converter_impl<Traits> Trivial ; + typedef mpl::identity <Trivial> TrivialQ ; + + typedef get_non_trivial_converter< Traits + ,OverflowHandler + ,Float2IntRounder + ,RawConverter + ,UserRangeChecker + > NonTrivialQ ; + + typedef typename Traits::trivial trivial ; + + typedef typename mpl::eval_if<trivial,TrivialQ,NonTrivialQ>::type type ; + } ; + +} } } // namespace boost::numeric::convdetail + +#endif + + |