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- // boost cast.hpp header file ----------------------------------------------//
- // (C) Copyright Kevlin Henney and Dave Abrahams 1999.
- // Distributed under 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 http://www.boost.org/libs/conversion for Documentation.
- // Revision History
- // 02 Jun 14 Remove VC6 workarounds.
- // 16 Jul 11 Bugfixes for VC6.
- // 23 JUN 05 Code extracted from /boost/cast.hpp into this new header.
- // Keeps this legacy version of numeric_cast<> for old compilers
- // wich can't compile the new version in /boost/numeric/conversion/cast.hpp
- // (Fernando Cacciola)
- // 02 Apr 01 Removed BOOST_NO_LIMITS workarounds and included
- // <boost/limits.hpp> instead (the workaround did not
- // actually compile when BOOST_NO_LIMITS was defined in
- // any case, so we loose nothing). (John Maddock)
- // 21 Jan 01 Undid a bug I introduced yesterday. numeric_cast<> never
- // worked with stock GCC; trying to get it to do that broke
- // vc-stlport.
- // 20 Jan 01 Moved BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS to config.hpp.
- // Removed unused BOOST_EXPLICIT_TARGET macro. Moved
- // boost::detail::type to boost/type.hpp. Made it compile with
- // stock gcc again (Dave Abrahams)
- // 29 Nov 00 Remove nested namespace cast, cleanup spacing before Formal
- // Review (Beman Dawes)
- // 19 Oct 00 Fix numeric_cast for floating-point types (Dave Abrahams)
- // 15 Jul 00 Suppress numeric_cast warnings for GCC, Borland and MSVC
- // (Dave Abrahams)
- // 30 Jun 00 More MSVC6 wordarounds. See comments below. (Dave Abrahams)
- // 28 Jun 00 Removed implicit_cast<>. See comment below. (Beman Dawes)
- // 27 Jun 00 More MSVC6 workarounds
- // 15 Jun 00 Add workarounds for MSVC6
- // 2 Feb 00 Remove bad_numeric_cast ";" syntax error (Doncho Angelov)
- // 26 Jan 00 Add missing throw() to bad_numeric_cast::what(0 (Adam Levar)
- // 29 Dec 99 Change using declarations so usages in other namespaces work
- // correctly (Dave Abrahams)
- // 23 Sep 99 Change polymorphic_downcast assert to also detect M.I. errors
- // as suggested Darin Adler and improved by Valentin Bonnard.
- // 2 Sep 99 Remove controversial asserts, simplify, rename.
- // 30 Aug 99 Move to cast.hpp, replace value_cast with numeric_cast,
- // place in nested namespace.
- // 3 Aug 99 Initial version
- #ifndef BOOST_OLD_NUMERIC_CAST_HPP
- #define BOOST_OLD_NUMERIC_CAST_HPP
- # include <boost/config.hpp>
- # include <cassert>
- # include <typeinfo>
- # include <boost/type.hpp>
- # include <boost/limits.hpp>
- # include <boost/numeric/conversion/converter_policies.hpp>
- namespace boost
- {
- using numeric::bad_numeric_cast;
- // LEGACY numeric_cast [only for some old broken compilers] --------------------------------------//
- // Contributed by Kevlin Henney
- // numeric_cast ------------------------------------------------------------//
- #if !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) || defined(BOOST_SGI_CPP_LIMITS)
- namespace detail
- {
- template <class T>
- struct signed_numeric_limits : std::numeric_limits<T>
- {
- static inline T min BOOST_PREVENT_MACRO_SUBSTITUTION ()
- {
- return (std::numeric_limits<T>::min)() >= 0
- // unary minus causes integral promotion, thus the static_cast<>
- ? static_cast<T>(-(std::numeric_limits<T>::max)())
- : (std::numeric_limits<T>::min)();
- };
- };
- // Move to namespace boost in utility.hpp?
- template <class T, bool specialized>
- struct fixed_numeric_limits_base
- : public if_true< std::numeric_limits<T>::is_signed >
- ::BOOST_NESTED_TEMPLATE then< signed_numeric_limits<T>,
- std::numeric_limits<T>
- >::type
- {};
- template <class T>
- struct fixed_numeric_limits
- : fixed_numeric_limits_base<T,(std::numeric_limits<T>::is_specialized)>
- {};
- # ifdef BOOST_HAS_LONG_LONG
- // cover implementations which supply no specialization for long
- // long / unsigned long long. Not intended to be full
- // numeric_limits replacements, but good enough for numeric_cast<>
- template <>
- struct fixed_numeric_limits_base< ::boost::long_long_type, false>
- {
- BOOST_STATIC_CONSTANT(bool, is_specialized = true);
- BOOST_STATIC_CONSTANT(bool, is_signed = true);
- static ::boost::long_long_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
- {
- # ifdef LONGLONG_MAX
- return LONGLONG_MAX;
- # else
- return 9223372036854775807LL; // hope this is portable
- # endif
- }
- static ::boost::long_long_type min BOOST_PREVENT_MACRO_SUBSTITUTION ()
- {
- # ifdef LONGLONG_MIN
- return LONGLONG_MIN;
- # else
- return -( 9223372036854775807LL )-1; // hope this is portable
- # endif
- }
- };
- template <>
- struct fixed_numeric_limits_base< ::boost::ulong_long_type, false>
- {
- BOOST_STATIC_CONSTANT(bool, is_specialized = true);
- BOOST_STATIC_CONSTANT(bool, is_signed = false);
- static ::boost::ulong_long_type max BOOST_PREVENT_MACRO_SUBSTITUTION ()
- {
- # ifdef ULONGLONG_MAX
- return ULONGLONG_MAX;
- # else
- return 0xffffffffffffffffULL; // hope this is portable
- # endif
- }
- static ::boost::ulong_long_type min BOOST_PREVENT_MACRO_SUBSTITUTION () { return 0; }
- };
- # endif
- } // namespace detail
- // less_than_type_min -
- // x_is_signed should be numeric_limits<X>::is_signed
- // y_is_signed should be numeric_limits<Y>::is_signed
- // y_min should be numeric_limits<Y>::min()
- //
- // check(x, y_min) returns true iff x < y_min without invoking comparisons
- // between signed and unsigned values.
- //
- // "poor man's partial specialization" is in use here.
- template <bool x_is_signed, bool y_is_signed>
- struct less_than_type_min
- {
- template <class X, class Y>
- static bool check(X x, Y y_min)
- { return x < y_min; }
- };
- template <>
- struct less_than_type_min<false, true>
- {
- template <class X, class Y>
- static bool check(X, Y)
- { return false; }
- };
- template <>
- struct less_than_type_min<true, false>
- {
- template <class X, class Y>
- static bool check(X x, Y)
- { return x < 0; }
- };
- // greater_than_type_max -
- // same_sign should be:
- // numeric_limits<X>::is_signed == numeric_limits<Y>::is_signed
- // y_max should be numeric_limits<Y>::max()
- //
- // check(x, y_max) returns true iff x > y_max without invoking comparisons
- // between signed and unsigned values.
- //
- // "poor man's partial specialization" is in use here.
- template <bool same_sign, bool x_is_signed>
- struct greater_than_type_max;
- template<>
- struct greater_than_type_max<true, true>
- {
- template <class X, class Y>
- static inline bool check(X x, Y y_max)
- { return x > y_max; }
- };
- template <>
- struct greater_than_type_max<false, true>
- {
- // What does the standard say about this? I think it's right, and it
- // will work with every compiler I know of.
- template <class X, class Y>
- static inline bool check(X x, Y)
- { return x >= 0 && static_cast<X>(static_cast<Y>(x)) != x; }
- };
- template<>
- struct greater_than_type_max<true, false>
- {
- template <class X, class Y>
- static inline bool check(X x, Y y_max)
- { return x > y_max; }
- };
- template <>
- struct greater_than_type_max<false, false>
- {
- // What does the standard say about this? I think it's right, and it
- // will work with every compiler I know of.
- template <class X, class Y>
- static inline bool check(X x, Y)
- { return static_cast<X>(static_cast<Y>(x)) != x; }
- };
- #else // use #pragma hacks if available
- namespace detail
- {
- # if BOOST_MSVC
- # pragma warning(push)
- # pragma warning(disable : 4018)
- # pragma warning(disable : 4146)
- #elif defined(BOOST_BORLANDC)
- # pragma option push -w-8041
- # endif
- // Move to namespace boost in utility.hpp?
- template <class T>
- struct fixed_numeric_limits : public std::numeric_limits<T>
- {
- static inline T min BOOST_PREVENT_MACRO_SUBSTITUTION ()
- {
- return std::numeric_limits<T>::is_signed && (std::numeric_limits<T>::min)() >= 0
- ? T(-(std::numeric_limits<T>::max)()) : (std::numeric_limits<T>::min)();
- }
- };
- # if BOOST_MSVC
- # pragma warning(pop)
- #elif defined(BOOST_BORLANDC)
- # pragma option pop
- # endif
- } // namespace detail
- #endif
- template<typename Target, typename Source>
- inline Target numeric_cast(Source arg)
- {
- // typedefs abbreviating respective trait classes
- typedef detail::fixed_numeric_limits<Source> arg_traits;
- typedef detail::fixed_numeric_limits<Target> result_traits;
- #if defined(BOOST_STRICT_CONFIG) \
- || (!defined(__HP_aCC) || __HP_aCC > 33900) \
- && (!defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) \
- || defined(BOOST_SGI_CPP_LIMITS))
- // typedefs that act as compile time assertions
- // (to be replaced by boost compile time assertions
- // as and when they become available and are stable)
- typedef bool argument_must_be_numeric[arg_traits::is_specialized];
- typedef bool result_must_be_numeric[result_traits::is_specialized];
- const bool arg_is_signed = arg_traits::is_signed;
- const bool result_is_signed = result_traits::is_signed;
- const bool same_sign = arg_is_signed == result_is_signed;
- if (less_than_type_min<arg_is_signed, result_is_signed>::check(arg, (result_traits::min)())
- || greater_than_type_max<same_sign, arg_is_signed>::check(arg, (result_traits::max)())
- )
- #else // We need to use #pragma hacks if available
- # if BOOST_MSVC
- # pragma warning(push)
- # pragma warning(disable : 4018)
- #elif defined(BOOST_BORLANDC)
- #pragma option push -w-8012
- # endif
- if ((arg < 0 && !result_traits::is_signed) // loss of negative range
- || (arg_traits::is_signed && arg < (result_traits::min)()) // underflow
- || arg > (result_traits::max)()) // overflow
- # if BOOST_MSVC
- # pragma warning(pop)
- #elif defined(BOOST_BORLANDC)
- #pragma option pop
- # endif
- #endif
- {
- throw bad_numeric_cast();
- }
- return static_cast<Target>(arg);
- } // numeric_cast
- } // namespace boost
- #endif // BOOST_OLD_NUMERIC_CAST_HPP
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