// (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_CONVERTER_POLICIES_FLC_12NOV2002_HPP #define BOOST_NUMERIC_CONVERSION_CONVERTER_POLICIES_FLC_12NOV2002_HPP #include <typeinfo> // for std::bad_cast #include <boost/config/no_tr1/cmath.hpp> // for std::floor and std::ceil #include <boost/throw_exception.hpp> #include <functional> #include "boost/type_traits/is_arithmetic.hpp" #include "boost/mpl/if.hpp" #include "boost/mpl/integral_c.hpp" namespace boost { namespace numeric { template<class S> struct Trunc { typedef S source_type ; typedef typename mpl::if_< is_arithmetic<S>,S,S const&>::type argument_type ; static source_type nearbyint ( argument_type s ) { #if !defined(BOOST_NO_STDC_NAMESPACE) using std::floor ; using std::ceil ; #endif return s < static_cast<S>(0) ? ceil(s) : floor(s) ; } typedef mpl::integral_c< std::float_round_style, std::round_toward_zero> round_style ; } ; template<class S> struct Floor { typedef S source_type ; typedef typename mpl::if_< is_arithmetic<S>,S,S const&>::type argument_type ; static source_type nearbyint ( argument_type s ) { #if !defined(BOOST_NO_STDC_NAMESPACE) using std::floor ; #endif return floor(s) ; } typedef mpl::integral_c< std::float_round_style, std::round_toward_neg_infinity> round_style ; } ; template<class S> struct Ceil { typedef S source_type ; typedef typename mpl::if_< is_arithmetic<S>,S,S const&>::type argument_type ; static source_type nearbyint ( argument_type s ) { #if !defined(BOOST_NO_STDC_NAMESPACE) using std::ceil ; #endif return ceil(s) ; } typedef mpl::integral_c< std::float_round_style, std::round_toward_infinity> round_style ; } ; template<class S> struct RoundEven { typedef S source_type ; typedef typename mpl::if_< is_arithmetic<S>,S,S const&>::type argument_type ; static source_type nearbyint ( argument_type s ) { // Algorithm contributed by Guillaume Melquiond #if !defined(BOOST_NO_STDC_NAMESPACE) using std::floor ; using std::ceil ; #endif // only works inside the range not at the boundaries S prev = floor(s); S next = ceil(s); S rt = (s - prev) - (next - s); // remainder type S const zero(0.0); S const two(2.0); if ( rt < zero ) return prev; else if ( rt > zero ) return next; else { bool is_prev_even = two * floor(prev / two) == prev ; return ( is_prev_even ? prev : next ) ; } } typedef mpl::integral_c< std::float_round_style, std::round_to_nearest> round_style ; } ; enum range_check_result { cInRange = 0 , cNegOverflow = 1 , cPosOverflow = 2 } ; class bad_numeric_cast : public std::bad_cast { public: virtual const char * what() const throw() { return "bad numeric conversion: overflow"; } }; class negative_overflow : public bad_numeric_cast { public: virtual const char * what() const throw() { return "bad numeric conversion: negative overflow"; } }; class positive_overflow : public bad_numeric_cast { public: virtual const char * what() const throw() { return "bad numeric conversion: positive overflow"; } }; struct def_overflow_handler { void operator() ( range_check_result r ) // throw(negative_overflow,positive_overflow) { #ifndef BOOST_NO_EXCEPTIONS if ( r == cNegOverflow ) throw negative_overflow() ; else if ( r == cPosOverflow ) throw positive_overflow() ; #else if ( r == cNegOverflow ) ::boost::throw_exception(negative_overflow()) ; else if ( r == cPosOverflow ) ::boost::throw_exception(positive_overflow()) ; #endif } } ; struct silent_overflow_handler { void operator() ( range_check_result ) {} // throw() } ; template<class Traits> struct raw_converter { typedef typename Traits::result_type result_type ; typedef typename Traits::argument_type argument_type ; static result_type low_level_convert ( argument_type s ) { return static_cast<result_type>(s) ; } } ; struct UseInternalRangeChecker {} ; } } // namespace boost::numeric #endif