[857] | 1 | // (C) Copyright John Maddock 2005.
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| 2 | // Use, modification and distribution are subject to the
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| 3 | // Boost Software License, Version 1.0. (See accompanying file
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| 4 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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| 5 |
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| 6 | #ifndef BOOST_TYPE_TRAITS_INTEGRAL_CONSTANT_HPP
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| 7 | #define BOOST_TYPE_TRAITS_INTEGRAL_CONSTANT_HPP
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| 8 |
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| 9 | #include <boost/config.hpp>
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| 10 | #include <boost/mpl/bool.hpp>
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| 11 | #include <boost/mpl/integral_c.hpp>
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| 12 |
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| 13 | namespace boost{
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| 14 |
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| 15 | #if defined(BOOST_NO_DEPENDENT_TYPES_IN_TEMPLATE_VALUE_PARAMETERS) || defined(__BORLANDC__)
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| 16 | template <class T, int val>
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| 17 | #else
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| 18 | template <class T, T val>
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| 19 | #endif
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| 20 | struct integral_constant : public mpl::integral_c<T, val>
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| 21 | {
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| 22 | //BOOST_STATIC_CONSTANT(T, value = val);
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| 23 | //typedef T value_type;
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| 24 | typedef integral_constant<T,val> type;
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| 25 |
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| 26 | #if 0
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| 27 | //
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| 28 | // everything that follows now, is MPL-compatibility code:
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| 29 | //
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| 30 | typedef ::boost::mpl::integral_c_tag tag;
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| 31 |
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| 32 | // have to #ifdef here: some compilers don't like the 'val + 1' form (MSVC),
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| 33 | // while some other don't like 'value + 1' (Borland), and some don't like
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| 34 | // either
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| 35 | #if BOOST_WORKAROUND(__EDG_VERSION__, <= 243)
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| 36 | private:
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| 37 | BOOST_STATIC_CONSTANT(T, next_value = BOOST_MPL_AUX_STATIC_CAST(T, (val + 1)));
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| 38 | BOOST_STATIC_CONSTANT(T, prior_value = BOOST_MPL_AUX_STATIC_CAST(T, (val - 1)));
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| 39 | public:
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| 40 | typedef integral_constant<T,next_value> next;
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| 41 | typedef integral_constant<T,prior_value> prior;
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| 42 | #elif BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x561)) \
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| 43 | || BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(502)) \
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| 44 | || BOOST_WORKAROUND(__HP_aCC, BOOST_TESTED_AT(53800))
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| 45 | typedef integral_constant<T, ( BOOST_MPL_AUX_STATIC_CAST(T, (val + 1)) )> next;
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| 46 | typedef integral_constant<T, ( BOOST_MPL_AUX_STATIC_CAST(T, (val - 1)) )> prior;
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| 47 | #else
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| 48 | typedef integral_constant<T, ( BOOST_MPL_AUX_STATIC_CAST(T, (value + 1)) )> next;
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| 49 | typedef integral_constant<T, ( BOOST_MPL_AUX_STATIC_CAST(T, (value - 1)) )> prior;
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| 50 | #endif
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| 51 |
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| 52 | // enables uniform function call syntax for families of overloaded
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| 53 | // functions that return objects of both arithmetic ('int', 'long',
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| 54 | // 'double', etc.) and wrapped integral types (for an example, see
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| 55 | // "mpl/example/power.cpp")
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| 56 | operator T() const { return static_cast<T>(this->value); }
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| 57 | #endif
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| 58 | };
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| 59 |
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| 60 | template<> struct integral_constant<bool,true> : public mpl::true_
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| 61 | {
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| 62 | #if BOOST_WORKAROUND(BOOST_MSVC, <= 1200)
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| 63 | typedef mpl::true_ base_;
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| 64 | using base_::value;
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| 65 | #endif
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| 66 | typedef integral_constant<bool,true> type;
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| 67 | };
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| 68 | template<> struct integral_constant<bool,false> : public mpl::false_
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| 69 | {
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| 70 | #if BOOST_WORKAROUND(BOOST_MSVC, <= 1200)
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| 71 | typedef mpl::false_ base_;
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| 72 | using base_::value;
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| 73 | #endif
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| 74 | typedef integral_constant<bool,false> type;
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| 75 | };
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| 76 |
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| 77 | typedef integral_constant<bool,true> true_type;
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| 78 | typedef integral_constant<bool,false> false_type;
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| 79 |
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| 80 | }
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| 81 |
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| 82 | #endif
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