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author | Remko Tronçon <git@el-tramo.be> | 2010-03-28 15:46:49 (GMT) |
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committer | Remko Tronçon <git@el-tramo.be> | 2010-03-28 15:46:49 (GMT) |
commit | f53a1ef582494458301b97bf6e546be52d7ff7e8 (patch) | |
tree | 7571b5cbcbd8a8f1dd1c966c9045b6cb69f0e295 /3rdParty/Boost/src/boost/numeric/conversion/detail/is_subranged.hpp | |
parent | 638345680d72ca6acaf123f2c8c1c391f696e371 (diff) | |
download | swift-f53a1ef582494458301b97bf6e546be52d7ff7e8.zip swift-f53a1ef582494458301b97bf6e546be52d7ff7e8.tar.bz2 |
Moving submodule contents back.
Diffstat (limited to '3rdParty/Boost/src/boost/numeric/conversion/detail/is_subranged.hpp')
-rw-r--r-- | 3rdParty/Boost/src/boost/numeric/conversion/detail/is_subranged.hpp | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/boost/numeric/conversion/detail/is_subranged.hpp b/3rdParty/Boost/src/boost/numeric/conversion/detail/is_subranged.hpp new file mode 100644 index 0000000..b5e7fe8 --- /dev/null +++ b/3rdParty/Boost/src/boost/numeric/conversion/detail/is_subranged.hpp @@ -0,0 +1,234 @@ +// (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_IS_SUBRANGED_FLC_12NOV2002_HPP +#define BOOST_NUMERIC_CONVERSION_DETAIL_IS_SUBRANGED_FLC_12NOV2002_HPP + +#include "boost/config.hpp" +#include "boost/limits.hpp" + +#include "boost/mpl/int.hpp" +#include "boost/mpl/multiplies.hpp" +#include "boost/mpl/less.hpp" +#include "boost/mpl/equal_to.hpp" + +#include "boost/type_traits/is_same.hpp" + +#include "boost/numeric/conversion/detail/meta.hpp" +#include "boost/numeric/conversion/detail/int_float_mixture.hpp" +#include "boost/numeric/conversion/detail/sign_mixture.hpp" +#include "boost/numeric/conversion/detail/udt_builtin_mixture.hpp" + +namespace boost { namespace numeric { namespace convdetail +{ + //--------------------------------------------------------------- + // Implementations of the compile time predicate "T is subranged" + //--------------------------------------------------------------- + + // for integral to integral conversions + template<class T,class S> + struct subranged_Sig2Unsig + { + // Signed to unsigned conversions are 'subranged' because of possible loose + // of negative values. + typedef mpl::true_ type ; + } ; + + // for unsigned integral to signed integral conversions + template<class T,class S> + struct subranged_Unsig2Sig + { + // IMPORTANT NOTE: + // + // This code assumes that signed/unsigned integral values are represented + // such that: + // + // numeric_limits<signed T>::digits + 1 == numeric_limits<unsigned T>::digits + // + // The '+1' is required since numeric_limits<>::digits gives 1 bit less for signed integral types. + // + // This fact is used by the following logic: + // + // if ( (numeric_limits<T>::digits+1) < (2*numeric_limits<S>::digits) ) + // then the conversion is subranged. + // + + typedef mpl::int_< ::std::numeric_limits<S>::digits > S_digits ; + typedef mpl::int_< ::std::numeric_limits<T>::digits > T_digits ; + + // T is signed, so take digits+1 + typedef typename T_digits::next u_T_digits ; + + typedef mpl::int_<2> Two ; + + typedef typename mpl::multiplies<S_digits,Two>::type S_digits_times_2 ; + + typedef typename mpl::less<u_T_digits,S_digits_times_2>::type type ; + } ; + + // for integral to integral conversions of the same sign. + template<class T,class S> + struct subranged_SameSign + { + // An integral conversion of the same sign is subranged if digits(T) < digits(S). + + typedef mpl::int_< ::std::numeric_limits<S>::digits > S_digits ; + typedef mpl::int_< ::std::numeric_limits<T>::digits > T_digits ; + + typedef typename mpl::less<T_digits,S_digits>::type type ; + } ; + + // for integral to float conversions + template<class T,class S> + struct subranged_Int2Float + { + typedef mpl::false_ type ; + } ; + + // for float to integral conversions + template<class T,class S> + struct subranged_Float2Int + { + typedef mpl::true_ type ; + } ; + + // for float to float conversions + template<class T,class S> + struct subranged_Float2Float + { + // If both T and S are floats, + // compare exponent bits and if they match, mantisa bits. + + typedef mpl::int_< ::std::numeric_limits<S>::digits > S_mantisa ; + typedef mpl::int_< ::std::numeric_limits<T>::digits > T_mantisa ; + + typedef mpl::int_< ::std::numeric_limits<S>::max_exponent > S_exponent ; + typedef mpl::int_< ::std::numeric_limits<T>::max_exponent > T_exponent ; + + typedef typename mpl::less<T_exponent,S_exponent>::type T_smaller_exponent ; + + typedef typename mpl::equal_to<T_exponent,S_exponent>::type equal_exponents ; + + typedef mpl::less<T_mantisa,S_mantisa> T_smaller_mantisa ; + + typedef mpl::eval_if<equal_exponents,T_smaller_mantisa,mpl::false_> not_bigger_exponent_case ; + + typedef typename + mpl::eval_if<T_smaller_exponent,mpl::true_,not_bigger_exponent_case>::type + type ; + } ; + + // for Udt to built-in conversions + template<class T,class S> + struct subranged_Udt2BuiltIn + { + typedef mpl::true_ type ; + } ; + + // for built-in to Udt conversions + template<class T,class S> + struct subranged_BuiltIn2Udt + { + typedef mpl::false_ type ; + } ; + + // for Udt to Udt conversions + template<class T,class S> + struct subranged_Udt2Udt + { + typedef mpl::false_ type ; + } ; + + //------------------------------------------------------------------- + // Selectors for the implementations of the subranged predicate + //------------------------------------------------------------------- + + template<class T,class S> + struct get_subranged_Int2Int + { + typedef subranged_SameSign<T,S> Sig2Sig ; + typedef subranged_Sig2Unsig<T,S> Sig2Unsig ; + typedef subranged_Unsig2Sig<T,S> Unsig2Sig ; + typedef Sig2Sig Unsig2Unsig ; + + typedef typename get_sign_mixture<T,S>::type sign_mixture ; + + typedef typename + for_sign_mixture<sign_mixture, Sig2Sig, Sig2Unsig, Unsig2Sig, Unsig2Unsig>::type + type ; + } ; + + template<class T,class S> + struct get_subranged_BuiltIn2BuiltIn + { + typedef get_subranged_Int2Int<T,S> Int2IntQ ; + + typedef subranged_Int2Float <T,S> Int2Float ; + typedef subranged_Float2Int <T,S> Float2Int ; + typedef subranged_Float2Float<T,S> Float2Float ; + + typedef mpl::identity<Int2Float > Int2FloatQ ; + typedef mpl::identity<Float2Int > Float2IntQ ; + typedef mpl::identity<Float2Float> Float2FloatQ ; + + typedef typename get_int_float_mixture<T,S>::type int_float_mixture ; + + typedef for_int_float_mixture<int_float_mixture, Int2IntQ, Int2FloatQ, Float2IntQ, Float2FloatQ> for_ ; + + typedef typename for_::type selected ; + + typedef typename selected::type type ; + } ; + + template<class T,class S> + struct get_subranged + { + typedef get_subranged_BuiltIn2BuiltIn<T,S> BuiltIn2BuiltInQ ; + + typedef subranged_BuiltIn2Udt<T,S> BuiltIn2Udt ; + typedef subranged_Udt2BuiltIn<T,S> Udt2BuiltIn ; + typedef subranged_Udt2Udt<T,S> Udt2Udt ; + + typedef mpl::identity<BuiltIn2Udt> BuiltIn2UdtQ ; + typedef mpl::identity<Udt2BuiltIn> Udt2BuiltInQ ; + typedef mpl::identity<Udt2Udt > Udt2UdtQ ; + + typedef typename get_udt_builtin_mixture<T,S>::type udt_builtin_mixture ; + + typedef typename + for_udt_builtin_mixture<udt_builtin_mixture, BuiltIn2BuiltInQ, BuiltIn2UdtQ, Udt2BuiltInQ, Udt2UdtQ>::type + selected ; + + typedef typename selected::type selected2 ; + + typedef typename selected2::type type ; + } ; + + + //------------------------------------------------------------------- + // Top level implementation selector. + //------------------------------------------------------------------- + template<class T, class S> + struct get_is_subranged + { + typedef get_subranged<T,S> non_trivial_case ; + typedef mpl::identity<mpl::false_> trivial_case ; + + typedef is_same<T,S> is_trivial ; + + typedef typename mpl::if_<is_trivial,trivial_case,non_trivial_case>::type selected ; + + typedef typename selected::type type ; + } ; + +} } } // namespace boost::numeric::convdetail + +#endif + + |