1 | ///////////////////////////////////////////////////////////////////////////////
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2 | /// \file functional.hpp
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3 | ///
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4 | // Copyright 2005 Eric Niebler. 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 | #ifndef BOOST_NUMERIC_FUNCTIONAL_HPP_EAN_08_12_2005
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9 | #define BOOST_NUMERIC_FUNCTIONAL_HPP_EAN_08_12_2005
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10 |
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11 | #include <limits>
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12 | #include <functional>
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13 | #include <boost/static_assert.hpp>
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14 | #include <boost/mpl/if.hpp>
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15 | #include <boost/mpl/and.hpp>
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16 | #include <boost/type_traits/remove_const.hpp>
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17 | #include <boost/type_traits/add_reference.hpp>
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18 | #include <boost/type_traits/is_empty.hpp>
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19 | #include <boost/type_traits/is_integral.hpp>
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20 | #include <boost/type_traits/is_floating_point.hpp>
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21 | #include <boost/utility/enable_if.hpp>
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22 | #include <boost/typeof/typeof.hpp>
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23 | #include <boost/accumulators/numeric/functional_fwd.hpp>
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24 | #include <boost/accumulators/numeric/detail/function1.hpp>
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25 | #include <boost/accumulators/numeric/detail/function2.hpp>
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26 | #include <boost/accumulators/numeric/detail/pod_singleton.hpp>
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27 |
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28 | #ifdef BOOST_NUMERIC_FUNCTIONAL_STD_VECTOR_SUPPORT
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29 | # include <boost/accumulators/numeric/functional/vector.hpp>
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30 | #endif
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31 |
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32 | #ifdef BOOST_NUMERIC_FUNCTIONAL_STD_VALARRAY_SUPPORT
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33 | # include <boost/accumulators/numeric/functional/valarray.hpp>
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34 | #endif
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35 |
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36 | #ifdef BOOST_NUMERIC_FUNCTIONAL_STD_COMPLEX_SUPPORT
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37 | # include <boost/accumulators/numeric/functional/complex.hpp>
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38 | #endif
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39 |
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40 | /// INTERNAL ONLY
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41 | ///
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42 | #define BOOST_NUMERIC_FUNCTIONAL_HPP_INCLUDED
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43 |
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44 | #ifdef BOOST_NUMERIC_FUNCTIONAL_DOXYGEN_INVOKED
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45 | // Hack to make Doxygen show the inheritance relationships
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46 | /// INTERNAL ONLY
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47 | ///
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48 | namespace std
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49 | {
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50 | /// INTERNAL ONLY
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51 | ///
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52 | template<class Arg, class Ret> struct unary_function {};
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53 | /// INTERNAL ONLY
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54 | ///
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55 | template<class Left, class Right, class Ret> struct binary_function {};
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56 | }
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57 | #endif
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58 |
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59 | namespace boost { namespace numeric
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60 | {
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61 | namespace functional
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62 | {
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63 | /// INTERNAL ONLY
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64 | ///
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65 | template<typename A0, typename A1>
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66 | struct are_integral
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67 | : mpl::and_<is_integral<A0>, is_integral<A1> >
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68 | {};
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69 |
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70 | template<typename Left, typename Right>
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71 | struct left_ref
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72 | {
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73 | typedef Left &type;
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74 | };
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75 |
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76 | namespace detail
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77 | {
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78 | template<typename T>
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79 | T &lvalue_of();
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80 | }
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81 | }
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82 |
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83 | // TODO: handle complex weight, valarray, MTL vectors
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84 |
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85 | /// INTERNAL ONLY
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86 | ///
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87 | #define BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(Name, Op) \
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88 | namespace functional \
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89 | { \
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90 | template<typename Arg> \
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91 | struct result_of_ ## Name \
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92 | { \
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93 | BOOST_TYPEOF_NESTED_TYPEDEF_TPL( \
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94 | nested \
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95 | , Op boost::numeric::functional::detail::lvalue_of<Arg>() \
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96 | ) \
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97 | typedef typename nested::type type; \
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98 | }; \
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99 | template<typename Arg, typename EnableIf> \
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100 | struct Name ## _base \
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101 | : std::unary_function< \
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102 | typename remove_const<Arg>::type \
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103 | , typename result_of_ ## Name<Arg>::type \
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104 | > \
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105 | { \
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106 | typename result_of_ ## Name<Arg>::type operator ()(Arg &arg) const \
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107 | { \
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108 | return Op arg; \
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109 | } \
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110 | }; \
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111 | template<typename Arg, typename ArgTag> \
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112 | struct Name \
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113 | : Name ## _base<Arg, void> \
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114 | {}; \
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115 | } \
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116 | namespace op \
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117 | { \
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118 | struct Name \
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119 | : boost::detail::function1<functional::Name<_, functional::tag<_> > > \
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120 | {}; \
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121 | } \
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122 | namespace \
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123 | { \
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124 | op::Name const &Name = boost::detail::pod_singleton<op::Name>::instance; \
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125 | } \
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126 | /**/
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127 |
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128 | /// INTERNAL ONLY
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129 | ///
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130 | #define BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(Name, Op, RetType) \
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131 | namespace functional \
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132 | { \
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133 | template<typename Left, typename Right, typename EnableIf> \
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134 | struct result_of_ ## Name \
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135 | { \
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136 | RetType(Left, Op, Right) \
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137 | }; \
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138 | template<typename Left, typename Right, typename EnableIf> \
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139 | struct Name ## _base \
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140 | : std::binary_function< \
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141 | typename remove_const<Left>::type \
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142 | , typename remove_const<Right>::type \
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143 | , typename result_of_ ## Name<Left, Right>::type \
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144 | > \
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145 | { \
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146 | typename result_of_ ## Name<Left, Right>::type \
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147 | operator ()(Left &left, Right &right) const \
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148 | { \
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149 | return left Op right; \
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150 | } \
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151 | }; \
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152 | template<typename Left, typename Right, typename LeftTag, typename RightTag> \
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153 | struct Name \
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154 | : Name ## _base<Left, Right, void> \
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155 | {}; \
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156 | } \
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157 | namespace op \
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158 | { \
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159 | struct Name \
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160 | : boost::detail::function2< \
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161 | functional::Name<_1, _2, functional::tag<_1>, functional::tag<_2> > \
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162 | > \
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163 | {}; \
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164 | } \
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165 | namespace \
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166 | { \
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167 | op::Name const &Name = boost::detail::pod_singleton<op::Name>::instance; \
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168 | } \
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169 | /**/
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170 |
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171 | /// INTERNAL ONLY
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172 | ///
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173 | #define BOOST_NUMERIC_FUNCTIONAL_DEDUCED(Left, Op, Right) \
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174 | BOOST_TYPEOF_NESTED_TYPEDEF_TPL( \
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175 | nested \
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176 | , boost::numeric::functional::detail::lvalue_of<Left>() Op \
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177 | boost::numeric::functional::detail::lvalue_of<Right>() \
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178 | ) \
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179 | typedef typename nested::type type; \
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180 | /**/
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181 |
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182 | /// INTERNAL ONLY
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183 | ///
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184 | #define BOOST_NUMERIC_FUNCTIONAL_LEFT(Left, Op, Right) \
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185 | typedef Left &type; \
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186 | /**/
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187 |
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188 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(plus, +, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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189 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(minus, -, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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190 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(multiplies, *, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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191 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(divides, /, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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192 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(modulus, %, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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193 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(greater, >, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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194 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(greater_equal, >=, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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195 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(less, <, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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196 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(less_equal, <=, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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197 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(equal_to, ==, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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198 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(not_equal_to, !=, BOOST_NUMERIC_FUNCTIONAL_DEDUCED)
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199 |
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200 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(assign, =, BOOST_NUMERIC_FUNCTIONAL_LEFT)
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201 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(plus_assign, +=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
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202 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(minus_assign, -=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
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203 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(multiplies_assign, *=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
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204 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(divides_assign, /=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
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205 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP(modulus_assign, %=, BOOST_NUMERIC_FUNCTIONAL_LEFT)
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206 |
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207 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(unary_plus, +)
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208 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(unary_minus, -)
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209 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(complement, ~)
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210 | BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP(logical_not, !)
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211 |
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212 | #undef BOOST_NUMERIC_FUNCTIONAL_LEFT
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213 | #undef BOOST_NUMERIC_FUNCTIONAL_DEDUCED
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214 | #undef BOOST_NUMERIC_FUNCTIONAL_DEFINE_UNARY_OP
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215 | #undef BOOST_NUMERIC_FUNCTIONAL_DEFINE_BINARY_OP
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216 |
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217 | namespace functional
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218 | {
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219 | template<typename Left, typename Right, typename EnableIf>
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220 | struct min_assign_base
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221 | : std::binary_function<Left, Right, void>
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222 | {
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223 | void operator ()(Left &left, Right &right) const
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224 | {
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225 | if(numeric::less(right, left))
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226 | {
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227 | left = right;
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228 | }
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229 | }
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230 | };
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231 |
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232 | template<typename Left, typename Right, typename EnableIf>
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233 | struct max_assign_base
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234 | : std::binary_function<Left, Right, void>
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235 | {
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236 | void operator ()(Left &left, Right &right) const
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237 | {
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238 | if(numeric::greater(right, left))
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239 | {
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240 | left = right;
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241 | }
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242 | }
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243 | };
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244 |
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245 | template<typename Left, typename Right, typename EnableIf>
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246 | struct average_base
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247 | : functional::divides<Left, Right>
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248 | {};
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249 |
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250 | // partial specialization that promotes the arguments to double for
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251 | // integral division.
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252 | template<typename Left, typename Right>
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253 | struct average_base<Left, Right, typename enable_if<are_integral<Left, Right> >::type>
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254 | : functional::divides<double const, double const>
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255 | {};
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256 |
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257 | template<typename To, typename From, typename EnableIf>
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258 | struct promote_base
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259 | : std::unary_function<From, To>
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260 | {
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261 | To operator ()(From &from) const
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262 | {
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263 | return from;
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264 | }
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265 | };
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266 |
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267 | template<typename ToFrom>
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268 | struct promote_base<ToFrom, ToFrom, void>
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269 | : std::unary_function<ToFrom, ToFrom>
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270 | {
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271 | ToFrom &operator ()(ToFrom &tofrom)
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272 | {
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273 | return tofrom;
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274 | }
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275 | };
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276 |
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277 | template<typename Arg, typename EnableIf>
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278 | struct as_min_base
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279 | : std::unary_function<Arg, typename remove_const<Arg>::type>
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280 | {
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281 | BOOST_STATIC_ASSERT(std::numeric_limits<typename remove_const<Arg>::type>::is_specialized);
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282 |
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283 | typename remove_const<Arg>::type operator ()(Arg &) const
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284 | {
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285 | return (std::numeric_limits<typename remove_const<Arg>::type>::min)();
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286 | }
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287 | };
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288 |
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289 | template<typename Arg>
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290 | struct as_min_base<Arg, typename enable_if<is_floating_point<Arg> >::type>
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291 | : std::unary_function<Arg, typename remove_const<Arg>::type>
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292 | {
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293 | BOOST_STATIC_ASSERT(std::numeric_limits<typename remove_const<Arg>::type>::is_specialized);
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294 |
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295 | typename remove_const<Arg>::type operator ()(Arg &) const
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296 | {
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297 | return -(std::numeric_limits<typename remove_const<Arg>::type>::max)();
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298 | }
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299 | };
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300 |
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301 | template<typename Arg, typename EnableIf>
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302 | struct as_max_base
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303 | : std::unary_function<Arg, typename remove_const<Arg>::type>
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304 | {
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305 | BOOST_STATIC_ASSERT(std::numeric_limits<typename remove_const<Arg>::type>::is_specialized);
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306 |
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307 | typename remove_const<Arg>::type operator ()(Arg &) const
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308 | {
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309 | return (std::numeric_limits<typename remove_const<Arg>::type>::max)();
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310 | }
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311 | };
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312 |
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313 | template<typename Arg, typename EnableIf>
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314 | struct as_zero_base
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315 | : std::unary_function<Arg, typename remove_const<Arg>::type>
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316 | {
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317 | typename remove_const<Arg>::type operator ()(Arg &) const
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318 | {
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319 | return numeric::zero<typename remove_const<Arg>::type>::value;
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320 | }
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321 | };
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322 |
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323 | template<typename Arg, typename EnableIf>
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324 | struct as_one_base
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325 | : std::unary_function<Arg, typename remove_const<Arg>::type>
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326 | {
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327 | typename remove_const<Arg>::type operator ()(Arg &) const
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328 | {
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329 | return numeric::one<typename remove_const<Arg>::type>::value;
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330 | }
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331 | };
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332 |
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333 | template<typename To, typename From, typename ToTag, typename FromTag>
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334 | struct promote
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335 | : promote_base<To, From, void>
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336 | {};
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337 |
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338 | template<typename Left, typename Right, typename LeftTag, typename RightTag>
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339 | struct min_assign
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340 | : min_assign_base<Left, Right, void>
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341 | {};
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342 |
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343 | template<typename Left, typename Right, typename LeftTag, typename RightTag>
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344 | struct max_assign
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345 | : max_assign_base<Left, Right, void>
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346 | {};
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347 |
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348 | template<typename Left, typename Right, typename LeftTag, typename RightTag>
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349 | struct average
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350 | : average_base<Left, Right, void>
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351 | {};
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352 |
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353 | template<typename Arg, typename Tag>
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354 | struct as_min
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355 | : as_min_base<Arg, void>
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356 | {};
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357 |
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358 | template<typename Arg, typename Tag>
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359 | struct as_max
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360 | : as_max_base<Arg, void>
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361 | {};
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362 |
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363 | template<typename Arg, typename Tag>
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364 | struct as_zero
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365 | : as_zero_base<Arg, void>
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366 | {};
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367 |
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368 | template<typename Arg, typename Tag>
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369 | struct as_one
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370 | : as_one_base<Arg, void>
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371 | {};
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372 | }
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373 |
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374 | namespace op
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375 | {
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376 | template<typename To>
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377 | struct promote
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378 | : boost::detail::function1<functional::promote<To, _, typename functional::tag<To>::type, functional::tag<_> > >
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379 | {};
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380 |
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381 | struct min_assign
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382 | : boost::detail::function2<functional::min_assign<_1, _2, functional::tag<_1>, functional::tag<_2> > >
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383 | {};
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384 |
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385 | struct max_assign
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386 | : boost::detail::function2<functional::max_assign<_1, _2, functional::tag<_1>, functional::tag<_2> > >
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387 | {};
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388 |
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389 | struct average
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390 | : boost::detail::function2<functional::average<_1, _2, functional::tag<_1>, functional::tag<_2> > >
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391 | {};
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392 |
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393 | struct as_min
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394 | : boost::detail::function1<functional::as_min<_, functional::tag<_> > >
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395 | {};
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396 |
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397 | struct as_max
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398 | : boost::detail::function1<functional::as_max<_, functional::tag<_> > >
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399 | {};
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400 |
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401 | struct as_zero
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402 | : boost::detail::function1<functional::as_zero<_, functional::tag<_> > >
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403 | {};
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404 |
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405 | struct as_one
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406 | : boost::detail::function1<functional::as_one<_, functional::tag<_> > >
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407 | {};
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408 | }
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409 |
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410 | namespace
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411 | {
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412 | op::min_assign const &min_assign = boost::detail::pod_singleton<op::min_assign>::instance;
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413 | op::max_assign const &max_assign = boost::detail::pod_singleton<op::max_assign>::instance;
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414 | op::average const &average = boost::detail::pod_singleton<op::average>::instance;
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415 | op::as_min const &as_min = boost::detail::pod_singleton<op::as_min>::instance;
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416 | op::as_max const &as_max = boost::detail::pod_singleton<op::as_max>::instance;
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417 | op::as_zero const &as_zero = boost::detail::pod_singleton<op::as_zero>::instance;
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418 | op::as_one const &as_one = boost::detail::pod_singleton<op::as_one>::instance;
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419 | }
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420 |
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421 | ///////////////////////////////////////////////////////////////////////////////
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422 | // promote
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423 | template<typename To, typename From>
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424 | typename lazy_disable_if<is_const<From>, mpl::if_<is_same<To, From>, To &, To> >::type
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425 | promote(From &from)
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426 | {
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427 | return functional::promote<To, From>()(from);
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428 | }
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429 |
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430 | template<typename To, typename From>
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431 | typename mpl::if_<is_same<To const, From const>, To const &, To const>::type
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432 | promote(From const &from)
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433 | {
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434 | return functional::promote<To const, From const>()(from);
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435 | }
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436 |
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437 | template<typename T>
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438 | struct default_
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439 | {
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440 | typedef default_ type;
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441 | typedef T value_type;
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442 | static T const value;
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443 |
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444 | operator T const & () const
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445 | {
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446 | return default_::value;
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447 | }
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448 | };
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449 |
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450 | template<typename T>
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451 | T const default_<T>::value = T();
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452 |
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453 | template<typename T>
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454 | struct one
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455 | {
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456 | typedef one type;
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457 | typedef T value_type;
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458 | static T const value;
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459 |
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460 | operator T const & () const
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461 | {
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462 | return one::value;
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463 | }
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464 | };
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465 |
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466 | template<typename T>
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467 | T const one<T>::value = T(1);
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468 |
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469 | template<typename T>
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470 | struct zero
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471 | {
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472 | typedef zero type;
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473 | typedef T value_type;
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474 | static T const value;
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475 |
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476 | operator T const & () const
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477 | {
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478 | return zero::value;
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479 | }
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480 | };
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481 |
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482 | template<typename T>
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483 | T const zero<T>::value = T();
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484 |
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485 | template<typename T>
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486 | struct one_or_default
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487 | : mpl::if_<is_empty<T>, default_<T>, one<T> >::type
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488 | {};
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489 |
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490 | template<typename T>
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491 | struct zero_or_default
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492 | : mpl::if_<is_empty<T>, default_<T>, zero<T> >::type
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493 | {};
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494 |
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495 | }} // namespace boost::numeric
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496 |
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497 | #endif
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