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- // (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 <functional>
- #include <typeinfo> // for std::bad_cast
- #include <boost/config.hpp>
- #include <boost/config/no_tr1/cmath.hpp> // for std::floor and std::ceil
- #include <boost/throw_exception.hpp>
- #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:
- const char * what() const BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE
- { return "bad numeric conversion: overflow"; }
- };
- class negative_overflow : public bad_numeric_cast
- {
- public:
- const char * what() const BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE
- { return "bad numeric conversion: negative overflow"; }
- };
- class positive_overflow : public bad_numeric_cast
- {
- public:
- const char * what() const BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE
- { 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
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