1 // © Copyright Fernando Luis Cacciola Carballal 2000-2004 |
1 // boost cast.hpp header file ----------------------------------------------// |
2 // Use, modification, and distribution is subject to the Boost Software |
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3 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
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4 // http://www.boost.org/LICENSE_1_0.txt) |
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5 |
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6 // See library home page at http://www.boost.org/libs/numeric/conversion |
3 // (C) Copyright Kevlin Henney and Dave Abrahams 1999. |
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4 // Distributed under the Boost |
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5 // Software License, Version 1.0. (See accompanying file |
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6 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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7 |
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8 // See http://www.boost.org/libs/conversion for Documentation. |
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9 |
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10 // Revision History |
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11 // 23 JUn 05 numeric_cast removed and redirected to the new verion (Fernando Cacciola) |
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12 // 02 Apr 01 Removed BOOST_NO_LIMITS workarounds and included |
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13 // <boost/limits.hpp> instead (the workaround did not |
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14 // actually compile when BOOST_NO_LIMITS was defined in |
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15 // any case, so we loose nothing). (John Maddock) |
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16 // 21 Jan 01 Undid a bug I introduced yesterday. numeric_cast<> never |
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17 // worked with stock GCC; trying to get it to do that broke |
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18 // vc-stlport. |
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19 // 20 Jan 01 Moved BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS to config.hpp. |
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20 // Removed unused BOOST_EXPLICIT_TARGET macro. Moved |
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21 // boost::detail::type to boost/type.hpp. Made it compile with |
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22 // stock gcc again (Dave Abrahams) |
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23 // 29 Nov 00 Remove nested namespace cast, cleanup spacing before Formal |
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24 // Review (Beman Dawes) |
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25 // 19 Oct 00 Fix numeric_cast for floating-point types (Dave Abrahams) |
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26 // 15 Jul 00 Suppress numeric_cast warnings for GCC, Borland and MSVC |
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27 // (Dave Abrahams) |
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28 // 30 Jun 00 More MSVC6 wordarounds. See comments below. (Dave Abrahams) |
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29 // 28 Jun 00 Removed implicit_cast<>. See comment below. (Beman Dawes) |
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30 // 27 Jun 00 More MSVC6 workarounds |
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31 // 15 Jun 00 Add workarounds for MSVC6 |
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32 // 2 Feb 00 Remove bad_numeric_cast ";" syntax error (Doncho Angelov) |
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33 // 26 Jan 00 Add missing throw() to bad_numeric_cast::what(0 (Adam Levar) |
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34 // 29 Dec 99 Change using declarations so usages in other namespaces work |
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35 // correctly (Dave Abrahams) |
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36 // 23 Sep 99 Change polymorphic_downcast assert to also detect M.I. errors |
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37 // as suggested Darin Adler and improved by Valentin Bonnard. |
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38 // 2 Sep 99 Remove controversial asserts, simplify, rename. |
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39 // 30 Aug 99 Move to cast.hpp, replace value_cast with numeric_cast, |
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40 // place in nested namespace. |
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41 // 3 Aug 99 Initial version |
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42 |
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43 #ifndef BOOST_CAST_HPP |
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44 #define BOOST_CAST_HPP |
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45 |
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46 # include <boost/config.hpp> |
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47 # include <boost/assert.hpp> |
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48 # include <typeinfo> |
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49 # include <boost/type.hpp> |
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50 # include <boost/limits.hpp> |
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51 # include <boost/detail/select_type.hpp> |
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52 |
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53 // It has been demonstrated numerous times that MSVC 6.0 fails silently at link |
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54 // time if you use a template function which has template parameters that don't |
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55 // appear in the function's argument list. |
7 // |
56 // |
8 // Contact the author at: fernando_cacciola@hotmail.com |
57 // TODO: Add this to config.hpp? |
9 // |
58 # if defined(BOOST_MSVC) && BOOST_MSVC < 1300 |
10 // |
59 # define BOOST_EXPLICIT_DEFAULT_TARGET , ::boost::type<Target>* = 0 |
11 // Revision History |
60 # else |
12 // |
61 # define BOOST_EXPLICIT_DEFAULT_TARGET |
13 // 19 Nov 2001 Syntatic changes as suggested by Darin Adler (Fernando Cacciola) |
62 # endif |
14 // 08 Nov 2001 Fixes to accommodate MSVC (Fernando Cacciola) |
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15 // 04 Nov 2001 Fixes to accommodate gcc2.92 (Fernando Cacciola) |
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16 // 30 Oct 2001 Some fixes suggested by Daryle Walker (Fernando Cacciola) |
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17 // 25 Oct 2001 Initial boostification (Fernando Cacciola) |
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18 // 23 Jan 2004 Inital add to cvs (post review)s |
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19 // |
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20 #ifndef BOOST_NUMERIC_CONVERSION_CAST_25OCT2001_HPP |
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21 #define BOOST_NUMERIC_CONVERSION_CAST_25OCT2001_HPP |
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22 |
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23 #include <boost/detail/workaround.hpp> |
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24 |
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25 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) |
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26 |
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27 # include<boost/numeric/conversion/detail/old_numeric_cast.hpp> |
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28 |
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29 #else |
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30 |
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31 #include <boost/type.hpp> |
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32 #include <boost/numeric/conversion/converter.hpp> |
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33 |
63 |
34 namespace boost |
64 namespace boost |
35 { |
65 { |
36 template<typename Target, typename Source> |
66 // See the documentation for descriptions of how to choose between |
37 inline |
67 // static_cast<>, dynamic_cast<>, polymorphic_cast<> and polymorphic_downcast<> |
38 Target numeric_cast ( Source arg ) |
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39 { |
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40 typedef boost::numeric::converter<Target,Source> Converter ; |
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41 return Converter::convert(arg); |
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42 } |
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43 |
68 |
44 using numeric::bad_numeric_cast; |
69 // polymorphic_cast --------------------------------------------------------// |
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70 |
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71 // Runtime checked polymorphic downcasts and crosscasts. |
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72 // Suggested in The C++ Programming Language, 3rd Ed, Bjarne Stroustrup, |
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73 // section 15.8 exercise 1, page 425. |
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74 |
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75 template <class Target, class Source> |
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76 inline Target polymorphic_cast(Source* x BOOST_EXPLICIT_DEFAULT_TARGET) |
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77 { |
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78 Target tmp = dynamic_cast<Target>(x); |
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79 if ( tmp == 0 ) throw std::bad_cast(); |
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80 return tmp; |
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81 } |
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82 |
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83 // polymorphic_downcast ----------------------------------------------------// |
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84 |
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85 // BOOST_ASSERT() checked polymorphic downcast. Crosscasts prohibited. |
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86 |
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87 // WARNING: Because this cast uses BOOST_ASSERT(), it violates |
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88 // the One Definition Rule if used in multiple translation units |
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89 // where BOOST_DISABLE_ASSERTS, BOOST_ENABLE_ASSERT_HANDLER |
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90 // NDEBUG are defined inconsistently. |
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91 |
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92 // Contributed by Dave Abrahams |
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93 |
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94 template <class Target, class Source> |
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95 inline Target polymorphic_downcast(Source* x BOOST_EXPLICIT_DEFAULT_TARGET) |
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96 { |
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97 BOOST_ASSERT( dynamic_cast<Target>(x) == x ); // detect logic error |
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98 return static_cast<Target>(x); |
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99 } |
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100 |
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101 # undef BOOST_EXPLICIT_DEFAULT_TARGET |
45 |
102 |
46 } // namespace boost |
103 } // namespace boost |
47 |
104 |
48 #endif |
105 # include <boost/numeric/conversion/cast.hpp> |
49 |
106 |
50 |
107 #endif // BOOST_CAST_HPP |
51 #endif |
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