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1 // boost integer.hpp header file -------------------------------------------// |
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2 |
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3 // Copyright Beman Dawes and Daryle Walker 1999. Distributed under the Boost |
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4 // Software License, Version 1.0. (See accompanying file |
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5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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6 |
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7 // See http://www.boost.org/libs/integer for documentation. |
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8 |
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9 // Revision History |
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10 // 22 Sep 01 Added value-based integer templates. (Daryle Walker) |
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11 // 01 Apr 01 Modified to use new <boost/limits.hpp> header. (John Maddock) |
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12 // 30 Jul 00 Add typename syntax fix (Jens Maurer) |
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13 // 28 Aug 99 Initial version |
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14 |
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15 #ifndef BOOST_INTEGER_HPP |
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16 #define BOOST_INTEGER_HPP |
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17 |
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18 #include <boost/integer_fwd.hpp> // self include |
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19 |
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20 #include <boost/integer_traits.hpp> // for boost::integer_traits |
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21 #include <boost/limits.hpp> // for std::numeric_limits |
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22 |
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23 namespace boost |
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24 { |
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25 |
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26 // Helper templates ------------------------------------------------------// |
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27 |
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28 // fast integers from least integers |
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29 // int_fast_t<> works correctly for unsigned too, in spite of the name. |
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30 template< typename LeastInt > |
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31 struct int_fast_t { typedef LeastInt fast; }; // imps may specialize |
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32 |
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33 // convert category to type |
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34 template< int Category > struct int_least_helper {}; // default is empty |
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35 |
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36 // specializatons: 1=long, 2=int, 3=short, 4=signed char, |
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37 // 6=unsigned long, 7=unsigned int, 8=unsigned short, 9=unsigned long |
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38 // no specializations for 0 and 5: requests for a type > long are in error |
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39 template<> struct int_least_helper<1> { typedef long least; }; |
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40 template<> struct int_least_helper<2> { typedef int least; }; |
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41 template<> struct int_least_helper<3> { typedef short least; }; |
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42 template<> struct int_least_helper<4> { typedef signed char least; }; |
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43 template<> struct int_least_helper<6> { typedef unsigned long least; }; |
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44 template<> struct int_least_helper<7> { typedef unsigned int least; }; |
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45 template<> struct int_least_helper<8> { typedef unsigned short least; }; |
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46 template<> struct int_least_helper<9> { typedef unsigned char least; }; |
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47 |
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48 // integer templates specifying number of bits ---------------------------// |
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49 |
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50 // signed |
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51 template< int Bits > // bits (including sign) required |
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52 struct int_t |
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53 { |
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54 typedef typename int_least_helper |
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55 < |
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56 (Bits-1 <= std::numeric_limits<long>::digits) + |
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57 (Bits-1 <= std::numeric_limits<int>::digits) + |
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58 (Bits-1 <= std::numeric_limits<short>::digits) + |
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59 (Bits-1 <= std::numeric_limits<signed char>::digits) |
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60 >::least least; |
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61 typedef typename int_fast_t<least>::fast fast; |
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62 }; |
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63 |
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64 // unsigned |
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65 template< int Bits > // bits required |
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66 struct uint_t |
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67 { |
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68 typedef typename int_least_helper |
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69 < |
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70 5 + |
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71 (Bits <= std::numeric_limits<unsigned long>::digits) + |
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72 (Bits <= std::numeric_limits<unsigned int>::digits) + |
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73 (Bits <= std::numeric_limits<unsigned short>::digits) + |
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74 (Bits <= std::numeric_limits<unsigned char>::digits) |
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75 >::least least; |
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76 typedef typename int_fast_t<least>::fast fast; |
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77 // int_fast_t<> works correctly for unsigned too, in spite of the name. |
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78 }; |
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79 |
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80 // integer templates specifying extreme value ----------------------------// |
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81 |
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82 // signed |
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83 template< long MaxValue > // maximum value to require support |
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84 struct int_max_value_t |
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85 { |
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86 typedef typename int_least_helper |
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87 < |
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88 (MaxValue <= integer_traits<long>::const_max) + |
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89 (MaxValue <= integer_traits<int>::const_max) + |
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90 (MaxValue <= integer_traits<short>::const_max) + |
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91 (MaxValue <= integer_traits<signed char>::const_max) |
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92 >::least least; |
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93 typedef typename int_fast_t<least>::fast fast; |
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94 }; |
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95 |
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96 template< long MinValue > // minimum value to require support |
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97 struct int_min_value_t |
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98 { |
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99 typedef typename int_least_helper |
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100 < |
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101 (MinValue >= integer_traits<long>::const_min) + |
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102 (MinValue >= integer_traits<int>::const_min) + |
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103 (MinValue >= integer_traits<short>::const_min) + |
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104 (MinValue >= integer_traits<signed char>::const_min) |
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105 >::least least; |
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106 typedef typename int_fast_t<least>::fast fast; |
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107 }; |
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108 |
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109 // unsigned |
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110 template< unsigned long Value > // maximum value to require support |
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111 struct uint_value_t |
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112 { |
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113 typedef typename int_least_helper |
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114 < |
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115 5 + |
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116 (Value <= integer_traits<unsigned long>::const_max) + |
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117 (Value <= integer_traits<unsigned int>::const_max) + |
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118 (Value <= integer_traits<unsigned short>::const_max) + |
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119 (Value <= integer_traits<unsigned char>::const_max) |
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120 >::least least; |
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121 typedef typename int_fast_t<least>::fast fast; |
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122 }; |
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123 |
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124 |
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125 } // namespace boost |
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126 |
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127 #endif // BOOST_INTEGER_HPP |