[857] | 1 | // operator_return_type_traits.hpp -- Boost Lambda Library ------------------
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| 2 |
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| 3 | // Copyright (C) 1999, 2000 Jaakko Järvi (jaakko.jarvi@cs.utu.fi)
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| 4 | //
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| 5 | // Distributed under the Boost Software License, Version 1.0. (See
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| 6 | // accompanying file LICENSE_1_0.txt or copy at
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| 7 | // http://www.boost.org/LICENSE_1_0.txt)
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| 8 | //
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| 9 | // For more information, see www.boost.org
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| 10 |
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| 11 | #ifndef BOOST_LAMBDA_OPERATOR_RETURN_TYPE_TRAITS_HPP
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| 12 | #define BOOST_LAMBDA_OPERATOR_RETURN_TYPE_TRAITS_HPP
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| 13 |
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| 14 | #include "boost/lambda/detail/is_instance_of.hpp"
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| 15 | #include "boost/type_traits/same_traits.hpp"
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| 16 |
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| 17 | #include "boost/indirect_reference.hpp"
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| 18 |
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| 19 | #include <cstddef> // needed for the ptrdiff_t
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| 20 | #include <iosfwd> // for istream and ostream
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| 21 |
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| 22 | #include <iterator> // needed for operator&
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| 23 |
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| 24 | namespace boost {
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| 25 | namespace lambda {
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| 26 | namespace detail {
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| 27 |
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| 28 | // -- general helper templates for type deduction ------------------
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| 29 |
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| 30 | // Much of the type deduction code for standard arithmetic types from Gary Powell
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| 31 |
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| 32 | template <class A> struct promote_code { static const int value = -1; };
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| 33 | // this means that a code is not defined for A
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| 34 |
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| 35 | // -- the next 5 types are needed in if_then_else_return
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| 36 | // the promotion order is not important, but they must have distinct values.
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| 37 | template <> struct promote_code<bool> { static const int value = 10; };
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| 38 | template <> struct promote_code<char> { static const int value = 20; };
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| 39 | template <> struct promote_code<unsigned char> { static const int value = 30; };
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| 40 | template <> struct promote_code<signed char> { static const int value = 40; };
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| 41 | template <> struct promote_code<short int> { static const int value = 50; };
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| 42 | // ----------
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| 43 |
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| 44 | template <> struct promote_code<int> { static const int value = 100; };
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| 45 | template <> struct promote_code<unsigned int> { static const int value = 200; };
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| 46 | template <> struct promote_code<long> { static const int value = 300; };
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| 47 | template <> struct promote_code<unsigned long> { static const int value = 400; };
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| 48 |
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| 49 | template <> struct promote_code<float> { static const int value = 500; };
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| 50 | template <> struct promote_code<double> { static const int value = 600; };
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| 51 | template <> struct promote_code<long double> { static const int value = 700; };
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| 52 |
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| 53 | // TODO: wchar_t
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| 54 |
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| 55 | // forward delcaration of complex.
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| 56 |
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| 57 | } // namespace detail
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| 58 | } // namespace lambda
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| 59 | } // namespace boost
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| 60 |
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| 61 | namespace std {
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| 62 | template<class T> class complex;
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| 63 | }
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| 64 |
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| 65 | namespace boost {
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| 66 | namespace lambda {
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| 67 | namespace detail {
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| 68 |
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| 69 | template <> struct promote_code< std::complex<float> > { static const int value = 800; };
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| 70 | template <> struct promote_code< std::complex<double> > { static const int value = 900; };
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| 71 | template <> struct promote_code< std::complex<long double> > { static const int value = 1000; };
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| 72 |
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| 73 | // -- int promotion -------------------------------------------
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| 74 | template <class T> struct promote_to_int { typedef T type; };
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| 75 |
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| 76 | template <> struct promote_to_int<bool> { typedef int type; };
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| 77 | template <> struct promote_to_int<char> { typedef int type; };
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| 78 | template <> struct promote_to_int<unsigned char> { typedef int type; };
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| 79 | template <> struct promote_to_int<signed char> { typedef int type; };
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| 80 | template <> struct promote_to_int<short int> { typedef int type; };
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| 81 |
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| 82 | // The unsigned short int promotion rule is this:
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| 83 | // unsigned short int to signed int if a signed int can hold all values
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| 84 | // of unsigned short int, otherwise go to unsigned int.
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| 85 | template <> struct promote_to_int<unsigned short int>
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| 86 | {
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| 87 | typedef
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| 88 | detail::IF<sizeof(int) <= sizeof(unsigned short int),
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| 89 | // I had the logic reversed but ">" messes up the parsing.
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| 90 | unsigned int,
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| 91 | int>::RET type;
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| 92 | };
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| 93 |
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| 94 |
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| 95 | // TODO: think, should there be default behaviour for non-standard types?
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| 96 |
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| 97 | } // namespace detail
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| 98 |
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| 99 | // ------------------------------------------
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| 100 | // Unary actions ----------------------------
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| 101 | // ------------------------------------------
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| 102 |
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| 103 | template<class Act, class A>
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| 104 | struct plain_return_type_1 {
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| 105 | typedef detail::unspecified type;
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| 106 | };
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| 107 |
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| 108 |
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| 109 |
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| 110 | template<class Act, class A>
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| 111 | struct plain_return_type_1<unary_arithmetic_action<Act>, A> {
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| 112 | typedef A type;
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| 113 | };
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| 114 |
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| 115 | template<class Act, class A>
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| 116 | struct return_type_1<unary_arithmetic_action<Act>, A> {
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| 117 | typedef
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| 118 | typename plain_return_type_1<
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| 119 | unary_arithmetic_action<Act>,
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| 120 | typename detail::remove_reference_and_cv<A>::type
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| 121 | >::type type;
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| 122 | };
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| 123 |
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| 124 |
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| 125 | template<class A>
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| 126 | struct plain_return_type_1<bitwise_action<not_action>, A> {
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| 127 | typedef A type;
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| 128 | };
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| 129 |
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| 130 | // bitwise not, operator~()
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| 131 | template<class A> struct return_type_1<bitwise_action<not_action>, A> {
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| 132 | typedef
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| 133 | typename plain_return_type_1<
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| 134 | bitwise_action<not_action>,
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| 135 | typename detail::remove_reference_and_cv<A>::type
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| 136 | >::type type;
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| 137 | };
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| 138 |
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| 139 |
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| 140 | // prefix increment and decrement operators return
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| 141 | // their argument by default as a non-const reference
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| 142 | template<class Act, class A>
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| 143 | struct plain_return_type_1<pre_increment_decrement_action<Act>, A> {
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| 144 | typedef A& type;
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| 145 | };
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| 146 |
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| 147 | template<class Act, class A>
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| 148 | struct return_type_1<pre_increment_decrement_action<Act>, A> {
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| 149 | typedef
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| 150 | typename plain_return_type_1<
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| 151 | pre_increment_decrement_action<Act>,
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| 152 | typename detail::remove_reference_and_cv<A>::type
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| 153 | >::type type;
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| 154 | };
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| 155 |
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| 156 | // post decrement just returns the same plain type.
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| 157 | template<class Act, class A>
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| 158 | struct plain_return_type_1<post_increment_decrement_action<Act>, A> {
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| 159 | typedef A type;
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| 160 | };
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| 161 |
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| 162 | template<class Act, class A>
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| 163 | struct return_type_1<post_increment_decrement_action<Act>, A>
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| 164 | {
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| 165 | typedef
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| 166 | typename plain_return_type_1<
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| 167 | post_increment_decrement_action<Act>,
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| 168 | typename detail::remove_reference_and_cv<A>::type
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| 169 | >::type type;
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| 170 | };
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| 171 |
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| 172 | // logical not, operator!()
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| 173 | template<class A>
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| 174 | struct plain_return_type_1<logical_action<not_action>, A> {
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| 175 | typedef bool type;
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| 176 | };
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| 177 |
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| 178 | template<class A>
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| 179 | struct return_type_1<logical_action<not_action>, A> {
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| 180 | typedef
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| 181 | typename plain_return_type_1<
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| 182 | logical_action<not_action>,
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| 183 | typename detail::remove_reference_and_cv<A>::type
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| 184 | >::type type;
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| 185 | };
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| 186 |
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| 187 | // address of action ---------------------------------------
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| 188 |
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| 189 |
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| 190 | template<class A>
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| 191 | struct return_type_1<other_action<addressof_action>, A> {
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| 192 | typedef
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| 193 | typename plain_return_type_1<
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| 194 | other_action<addressof_action>,
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| 195 | typename detail::remove_reference_and_cv<A>::type
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| 196 | >::type type1;
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| 197 |
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| 198 | // If no user defined specialization for A, then return the
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| 199 | // cv qualified pointer to A
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| 200 | typedef typename detail::IF<
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| 201 | boost::is_same<type1, detail::unspecified>::value,
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| 202 | typename boost::remove_reference<A>::type*,
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| 203 | type1
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| 204 | >::RET type;
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| 205 | };
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| 206 |
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| 207 | // contentsof action ------------------------------------
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| 208 |
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| 209 | // TODO: this deduction may lead to fail directly,
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| 210 | // (if A has no specialization for iterator_traits and has no
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| 211 | // typedef A::reference.
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| 212 | // There is no easy way around this, cause there doesn't seem to be a way
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| 213 | // to test whether a class is an iterator or not.
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| 214 |
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| 215 | // The default works with std::iterators.
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| 216 |
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| 217 | namespace detail {
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| 218 |
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| 219 | // A is a nonreference type
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| 220 | template <class A> struct contentsof_type {
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| 221 | typedef typename boost::indirect_reference<A>::type type;
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| 222 | };
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| 223 |
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| 224 | // this is since the nullary () in lambda_functor is always instantiated
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| 225 | template <> struct contentsof_type<null_type> {
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| 226 | typedef detail::unspecified type;
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| 227 | };
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| 228 |
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| 229 |
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| 230 | template <class A> struct contentsof_type<const A> {
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| 231 | typedef typename contentsof_type<A>::type type1;
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| 232 | // return a reference to the underlying const type
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| 233 | // the IF is because the A::reference in the primary template could
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| 234 | // be some class type rather than a real reference, hence
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| 235 | // we do not want to make it a reference here either
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| 236 | typedef typename detail::IF<
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| 237 | is_reference<type1>::value,
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| 238 | const typename boost::remove_reference<type1>::type &,
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| 239 | const type1
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| 240 | >::RET type;
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| 241 | };
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| 242 |
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| 243 | template <class A> struct contentsof_type<volatile A> {
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| 244 | typedef typename contentsof_type<A>::type type1;
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| 245 | typedef typename detail::IF<
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| 246 | is_reference<type1>::value,
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| 247 | volatile typename boost::remove_reference<type1>::type &,
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| 248 | volatile type1
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| 249 | >::RET type;
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| 250 | };
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| 251 |
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| 252 | template <class A> struct contentsof_type<const volatile A> {
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| 253 | typedef typename contentsof_type<A>::type type1;
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| 254 | typedef typename detail::IF<
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| 255 | is_reference<type1>::value,
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| 256 | const volatile typename boost::remove_reference<type1>::type &,
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| 257 | const volatile type1
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| 258 | >::RET type;
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| 259 | };
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| 260 |
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| 261 | // standard iterator traits should take care of the pointer types
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| 262 | // but just to be on the safe side, we have the specializations here:
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| 263 | // these work even if A is cv-qualified.
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| 264 | template <class A> struct contentsof_type<A*> {
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| 265 | typedef A& type;
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| 266 | };
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| 267 | template <class A> struct contentsof_type<A* const> {
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| 268 | typedef A& type;
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| 269 | };
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| 270 | template <class A> struct contentsof_type<A* volatile> {
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| 271 | typedef A& type;
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| 272 | };
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| 273 | template <class A> struct contentsof_type<A* const volatile> {
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| 274 | typedef A& type;
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| 275 | };
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| 276 |
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| 277 | template<class A, int N> struct contentsof_type<A[N]> {
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| 278 | typedef A& type;
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| 279 | };
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| 280 | template<class A, int N> struct contentsof_type<const A[N]> {
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| 281 | typedef const A& type;
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| 282 | };
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| 283 | template<class A, int N> struct contentsof_type<volatile A[N]> {
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| 284 | typedef volatile A& type;
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| 285 | };
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| 286 | template<class A, int N> struct contentsof_type<const volatile A[N]> {
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| 287 | typedef const volatile A& type;
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| 288 | };
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| 289 |
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| 290 |
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| 291 |
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| 292 |
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| 293 |
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| 294 | } // end detail
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| 295 |
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| 296 | template<class A>
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| 297 | struct return_type_1<other_action<contentsof_action>, A> {
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| 298 |
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| 299 | typedef
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| 300 | typename plain_return_type_1<
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| 301 | other_action<contentsof_action>,
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| 302 | typename detail::remove_reference_and_cv<A>::type
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| 303 | >::type type1;
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| 304 |
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| 305 | // If no user defined specialization for A, then return the
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| 306 | // cv qualified pointer to A
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| 307 | typedef typename
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| 308 | detail::IF_type<
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| 309 | boost::is_same<type1, detail::unspecified>::value,
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| 310 | detail::contentsof_type<
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| 311 | typename boost::remove_reference<A>::type
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| 312 | >,
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| 313 | detail::identity_mapping<type1>
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| 314 | >::type type;
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| 315 | };
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| 316 |
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| 317 |
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| 318 | // ------------------------------------------------------------------
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| 319 | // binary actions ---------------------------------------------------
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| 320 | // ------------------------------------------------------------------
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| 321 |
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| 322 | // here the default case is: no user defined versions:
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| 323 | template <class Act, class A, class B>
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| 324 | struct plain_return_type_2 {
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| 325 | typedef detail::unspecified type;
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| 326 | };
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| 327 |
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| 328 | namespace detail {
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| 329 |
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| 330 | // error classes
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| 331 | class illegal_pointer_arithmetic{};
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| 332 |
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| 333 | // pointer arithmetic type deductions ----------------------
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| 334 | // value = false means that this is not a pointer arithmetic case
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| 335 | // value = true means, that this can be a pointer arithmetic case, but not necessarily is
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| 336 | // This means, that for user defined operators for pointer types, say for some operator+(X, *Y),
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| 337 | // the deductions must be coded at an earliel level (return_type_2).
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| 338 |
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| 339 | template<class Act, class A, class B>
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| 340 | struct pointer_arithmetic_traits { static const bool value = false; };
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| 341 |
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| 342 | template<class A, class B>
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| 343 | struct pointer_arithmetic_traits<plus_action, A, B> {
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| 344 |
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| 345 | typedef typename
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| 346 | array_to_pointer<typename boost::remove_reference<A>::type>::type AP;
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| 347 | typedef typename
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| 348 | array_to_pointer<typename boost::remove_reference<B>::type>::type BP;
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| 349 |
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| 350 | static const bool is_pointer_A = boost::is_pointer<AP>::value;
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| 351 | static const bool is_pointer_B = boost::is_pointer<BP>::value;
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| 352 |
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| 353 | static const bool value = is_pointer_A || is_pointer_B;
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| 354 |
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| 355 | // can't add two pointers.
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| 356 | // note, that we do not check wether the other type is valid for
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| 357 | // addition with a pointer.
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| 358 | // the compiler will catch it in the apply function
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| 359 |
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| 360 | typedef typename
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| 361 | detail::IF<
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| 362 | is_pointer_A && is_pointer_B,
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| 363 | detail::return_type_deduction_failure<
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| 364 | detail::illegal_pointer_arithmetic
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| 365 | >,
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| 366 | typename detail::IF<is_pointer_A, AP, BP>::RET
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| 367 | >::RET type;
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| 368 |
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| 369 | };
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| 370 |
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| 371 | template<class A, class B>
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| 372 | struct pointer_arithmetic_traits<minus_action, A, B> {
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| 373 | typedef typename
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| 374 | array_to_pointer<typename boost::remove_reference<A>::type>::type AP;
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| 375 | typedef typename
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| 376 | array_to_pointer<typename boost::remove_reference<B>::type>::type BP;
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| 377 |
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| 378 | static const bool is_pointer_A = boost::is_pointer<AP>::value;
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| 379 | static const bool is_pointer_B = boost::is_pointer<BP>::value;
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| 380 |
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| 381 | static const bool value = is_pointer_A || is_pointer_B;
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| 382 |
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| 383 | static const bool same_pointer_type =
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| 384 | is_pointer_A && is_pointer_B &&
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| 385 | boost::is_same<
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| 386 | typename boost::remove_const<
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| 387 | typename boost::remove_pointer<
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| 388 | typename boost::remove_const<AP>::type
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| 389 | >::type
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| 390 | >::type,
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| 391 | typename boost::remove_const<
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| 392 | typename boost::remove_pointer<
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| 393 | typename boost::remove_const<BP>::type
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| 394 | >::type
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| 395 | >::type
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| 396 | >::value;
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| 397 |
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| 398 | // ptr - ptr has type ptrdiff_t
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| 399 | // note, that we do not check if, in ptr - B, B is
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| 400 | // valid for subtraction with a pointer.
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| 401 | // the compiler will catch it in the apply function
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| 402 |
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| 403 | typedef typename
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| 404 | detail::IF<
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| 405 | same_pointer_type, const std::ptrdiff_t,
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| 406 | typename detail::IF<
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| 407 | is_pointer_A,
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| 408 | AP,
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| 409 | detail::return_type_deduction_failure<detail::illegal_pointer_arithmetic>
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| 410 | >::RET
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| 411 | >::RET type;
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| 412 | };
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| 413 |
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| 414 | } // namespace detail
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| 415 |
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| 416 | // -- arithmetic actions ---------------------------------------------
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| 417 |
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| 418 | namespace detail {
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| 419 |
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| 420 | template<bool is_pointer_arithmetic, class Act, class A, class B>
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| 421 | struct return_type_2_arithmetic_phase_1;
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| 422 |
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| 423 | template<class A, class B> struct return_type_2_arithmetic_phase_2;
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| 424 | template<class A, class B> struct return_type_2_arithmetic_phase_3;
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| 425 |
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| 426 | } // namespace detail
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| 427 |
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| 428 |
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| 429 | // drop any qualifiers from the argument types within arithmetic_action
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| 430 | template<class A, class B, class Act>
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| 431 | struct return_type_2<arithmetic_action<Act>, A, B>
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| 432 | {
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| 433 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
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| 434 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
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| 435 |
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| 436 | typedef typename
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| 437 | plain_return_type_2<arithmetic_action<Act>, plain_A, plain_B>::type type1;
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| 438 |
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| 439 | // if user defined return type, do not enter the whole arithmetic deductions
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| 440 | typedef typename
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| 441 | detail::IF_type<
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| 442 | boost::is_same<type1, detail::unspecified>::value,
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| 443 | detail::return_type_2_arithmetic_phase_1<
|
---|
| 444 | detail::pointer_arithmetic_traits<Act, A, B>::value, Act, A, B
|
---|
| 445 | >,
|
---|
| 446 | plain_return_type_2<arithmetic_action<Act>, plain_A, plain_B>
|
---|
| 447 | >::type type;
|
---|
| 448 | };
|
---|
| 449 |
|
---|
| 450 | namespace detail {
|
---|
| 451 |
|
---|
| 452 | // perform integral promotion, no pointer arithmetic
|
---|
| 453 | template<bool is_pointer_arithmetic, class Act, class A, class B>
|
---|
| 454 | struct return_type_2_arithmetic_phase_1
|
---|
| 455 | {
|
---|
| 456 | typedef typename
|
---|
| 457 | return_type_2_arithmetic_phase_2<
|
---|
| 458 | typename remove_reference_and_cv<A>::type,
|
---|
| 459 | typename remove_reference_and_cv<B>::type
|
---|
| 460 | >::type type;
|
---|
| 461 | };
|
---|
| 462 |
|
---|
| 463 | // pointer_arithmetic
|
---|
| 464 | template<class Act, class A, class B>
|
---|
| 465 | struct return_type_2_arithmetic_phase_1<true, Act, A, B>
|
---|
| 466 | {
|
---|
| 467 | typedef typename
|
---|
| 468 | pointer_arithmetic_traits<Act, A, B>::type type;
|
---|
| 469 | };
|
---|
| 470 |
|
---|
| 471 | template<class A, class B>
|
---|
| 472 | struct return_type_2_arithmetic_phase_2 {
|
---|
| 473 | typedef typename
|
---|
| 474 | return_type_2_arithmetic_phase_3<
|
---|
| 475 | typename promote_to_int<A>::type,
|
---|
| 476 | typename promote_to_int<B>::type
|
---|
| 477 | >::type type;
|
---|
| 478 | };
|
---|
| 479 |
|
---|
| 480 | // specialization for unsigned int.
|
---|
| 481 | // We only have to do these two specialization because the value promotion will
|
---|
| 482 | // take care of the other cases.
|
---|
| 483 | // The unsigned int promotion rule is this:
|
---|
| 484 | // unsigned int to long if a long can hold all values of unsigned int,
|
---|
| 485 | // otherwise go to unsigned long.
|
---|
| 486 |
|
---|
| 487 | // struct so I don't have to type this twice.
|
---|
| 488 | struct promotion_of_unsigned_int
|
---|
| 489 | {
|
---|
| 490 | typedef
|
---|
| 491 | detail::IF<sizeof(long) <= sizeof(unsigned int),
|
---|
| 492 | unsigned long,
|
---|
| 493 | long>::RET type;
|
---|
| 494 | };
|
---|
| 495 |
|
---|
| 496 | template<>
|
---|
| 497 | struct return_type_2_arithmetic_phase_2<unsigned int, long>
|
---|
| 498 | {
|
---|
| 499 | typedef promotion_of_unsigned_int::type type;
|
---|
| 500 | };
|
---|
| 501 | template<>
|
---|
| 502 | struct return_type_2_arithmetic_phase_2<long, unsigned int>
|
---|
| 503 | {
|
---|
| 504 | typedef promotion_of_unsigned_int::type type;
|
---|
| 505 | };
|
---|
| 506 |
|
---|
| 507 |
|
---|
| 508 | template<class A, class B> struct return_type_2_arithmetic_phase_3 {
|
---|
| 509 | enum { promote_code_A_value = promote_code<A>::value,
|
---|
| 510 | promote_code_B_value = promote_code<B>::value }; // enums for KCC
|
---|
| 511 | typedef typename
|
---|
| 512 | detail::IF<
|
---|
| 513 | promote_code_A_value == -1 || promote_code_B_value == -1,
|
---|
| 514 | detail::return_type_deduction_failure<return_type_2_arithmetic_phase_3>,
|
---|
| 515 | typename detail::IF<
|
---|
| 516 | ((int)promote_code_A_value > (int)promote_code_B_value),
|
---|
| 517 | A,
|
---|
| 518 | B
|
---|
| 519 | >::RET
|
---|
| 520 | >::RET type;
|
---|
| 521 | };
|
---|
| 522 |
|
---|
| 523 | } // namespace detail
|
---|
| 524 |
|
---|
| 525 | // -- bitwise actions -------------------------------------------
|
---|
| 526 | // note: for integral types deuduction is similar to arithmetic actions.
|
---|
| 527 |
|
---|
| 528 | // drop any qualifiers from the argument types within arithmetic action
|
---|
| 529 | template<class A, class B, class Act>
|
---|
| 530 | struct return_type_2<bitwise_action<Act>, A, B>
|
---|
| 531 | {
|
---|
| 532 |
|
---|
| 533 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 534 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 535 |
|
---|
| 536 | typedef typename
|
---|
| 537 | plain_return_type_2<bitwise_action<Act>, plain_A, plain_B>::type type1;
|
---|
| 538 |
|
---|
| 539 | // if user defined return type, do not enter type deductions
|
---|
| 540 | typedef typename
|
---|
| 541 | detail::IF_type<
|
---|
| 542 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 543 | return_type_2<arithmetic_action<plus_action>, A, B>,
|
---|
| 544 | plain_return_type_2<bitwise_action<Act>, plain_A, plain_B>
|
---|
| 545 | >::type type;
|
---|
| 546 |
|
---|
| 547 | // plus_action is just a random pick, has to be a concrete instance
|
---|
| 548 |
|
---|
| 549 | // TODO: This check is only valid for built-in types, overloaded types might
|
---|
| 550 | // accept floating point operators
|
---|
| 551 |
|
---|
| 552 | // bitwise operators not defined for floating point types
|
---|
| 553 | // these test are not strictly needed here, since the error will be caught in
|
---|
| 554 | // the apply function
|
---|
| 555 | BOOST_STATIC_ASSERT(!(boost::is_float<plain_A>::value && boost::is_float<plain_B>::value));
|
---|
| 556 |
|
---|
| 557 | };
|
---|
| 558 |
|
---|
| 559 | namespace detail {
|
---|
| 560 |
|
---|
| 561 | #ifdef BOOST_NO_TEMPLATED_STREAMS
|
---|
| 562 |
|
---|
| 563 | template<class A, class B>
|
---|
| 564 | struct leftshift_type {
|
---|
| 565 |
|
---|
| 566 | typedef typename detail::IF<
|
---|
| 567 | boost::is_convertible<
|
---|
| 568 | typename boost::remove_reference<A>::type*,
|
---|
| 569 | std::ostream*
|
---|
| 570 | >::value,
|
---|
| 571 | std::ostream&,
|
---|
| 572 | typename detail::remove_reference_and_cv<A>::type
|
---|
| 573 | >::RET type;
|
---|
| 574 | };
|
---|
| 575 |
|
---|
| 576 | template<class A, class B>
|
---|
| 577 | struct rightshift_type {
|
---|
| 578 |
|
---|
| 579 | typedef typename detail::IF<
|
---|
| 580 |
|
---|
| 581 | boost::is_convertible<
|
---|
| 582 | typename boost::remove_reference<A>::type*,
|
---|
| 583 | std::istream*
|
---|
| 584 | >::value,
|
---|
| 585 | std::istream&,
|
---|
| 586 | typename detail::remove_reference_and_cv<A>::type
|
---|
| 587 | >::RET type;
|
---|
| 588 | };
|
---|
| 589 |
|
---|
| 590 | #else
|
---|
| 591 |
|
---|
| 592 | template <class T> struct get_ostream_type {
|
---|
| 593 | typedef std::basic_ostream<typename T::char_type,
|
---|
| 594 | typename T::traits_type>& type;
|
---|
| 595 | };
|
---|
| 596 |
|
---|
| 597 | template <class T> struct get_istream_type {
|
---|
| 598 | typedef std::basic_istream<typename T::char_type,
|
---|
| 599 | typename T::traits_type>& type;
|
---|
| 600 | };
|
---|
| 601 |
|
---|
| 602 | template<class A, class B>
|
---|
| 603 | struct leftshift_type {
|
---|
| 604 | private:
|
---|
| 605 | typedef typename boost::remove_reference<A>::type plainA;
|
---|
| 606 | public:
|
---|
| 607 | typedef typename detail::IF_type<
|
---|
| 608 | is_instance_of_2<plainA, std::basic_ostream>::value,
|
---|
| 609 | get_ostream_type<plainA>, //reference to the stream
|
---|
| 610 | detail::remove_reference_and_cv<A>
|
---|
| 611 | >::type type;
|
---|
| 612 | };
|
---|
| 613 |
|
---|
| 614 | template<class A, class B>
|
---|
| 615 | struct rightshift_type {
|
---|
| 616 | private:
|
---|
| 617 | typedef typename boost::remove_reference<A>::type plainA;
|
---|
| 618 | public:
|
---|
| 619 | typedef typename detail::IF_type<
|
---|
| 620 | is_instance_of_2<plainA, std::basic_istream>::value,
|
---|
| 621 | get_istream_type<plainA>, //reference to the stream
|
---|
| 622 | detail::remove_reference_and_cv<A>
|
---|
| 623 | >::type type;
|
---|
| 624 | };
|
---|
| 625 |
|
---|
| 626 |
|
---|
| 627 | #endif
|
---|
| 628 |
|
---|
| 629 | } // end detail
|
---|
| 630 |
|
---|
| 631 | // ostream
|
---|
| 632 | template<class A, class B>
|
---|
| 633 | struct return_type_2<bitwise_action<leftshift_action>, A, B>
|
---|
| 634 | {
|
---|
| 635 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 636 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 637 |
|
---|
| 638 | typedef typename
|
---|
| 639 | plain_return_type_2<bitwise_action<leftshift_action>, plain_A, plain_B>::type type1;
|
---|
| 640 |
|
---|
| 641 | // if user defined return type, do not enter type deductions
|
---|
| 642 | typedef typename
|
---|
| 643 | detail::IF_type<
|
---|
| 644 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 645 | detail::leftshift_type<A, B>,
|
---|
| 646 | plain_return_type_2<bitwise_action<leftshift_action>, plain_A, plain_B>
|
---|
| 647 | >::type type;
|
---|
| 648 | };
|
---|
| 649 |
|
---|
| 650 | // istream
|
---|
| 651 | template<class A, class B>
|
---|
| 652 | struct return_type_2<bitwise_action<rightshift_action>, A, B>
|
---|
| 653 | {
|
---|
| 654 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 655 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 656 |
|
---|
| 657 | typedef typename
|
---|
| 658 | plain_return_type_2<bitwise_action<rightshift_action>, plain_A, plain_B>::type type1;
|
---|
| 659 |
|
---|
| 660 | // if user defined return type, do not enter type deductions
|
---|
| 661 | typedef typename
|
---|
| 662 | detail::IF_type<
|
---|
| 663 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 664 | detail::rightshift_type<A, B>,
|
---|
| 665 | plain_return_type_2<bitwise_action<rightshift_action>, plain_A, plain_B>
|
---|
| 666 | >::type type;
|
---|
| 667 | };
|
---|
| 668 |
|
---|
| 669 | // -- logical actions ----------------------------------------
|
---|
| 670 | // always bool
|
---|
| 671 | // NOTE: this may not be true for some weird user-defined types,
|
---|
| 672 | template<class A, class B, class Act>
|
---|
| 673 | struct plain_return_type_2<logical_action<Act>, A, B> {
|
---|
| 674 | typedef bool type;
|
---|
| 675 | };
|
---|
| 676 |
|
---|
| 677 | template<class A, class B, class Act>
|
---|
| 678 | struct return_type_2<logical_action<Act>, A, B> {
|
---|
| 679 |
|
---|
| 680 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 681 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 682 |
|
---|
| 683 | typedef typename
|
---|
| 684 | plain_return_type_2<logical_action<Act>, plain_A, plain_B>::type type;
|
---|
| 685 |
|
---|
| 686 | };
|
---|
| 687 |
|
---|
| 688 |
|
---|
| 689 | // -- relational actions ----------------------------------------
|
---|
| 690 | // always bool
|
---|
| 691 | // NOTE: this may not be true for some weird user-defined types,
|
---|
| 692 | template<class A, class B, class Act>
|
---|
| 693 | struct plain_return_type_2<relational_action<Act>, A, B> {
|
---|
| 694 | typedef bool type;
|
---|
| 695 | };
|
---|
| 696 |
|
---|
| 697 | template<class A, class B, class Act>
|
---|
| 698 | struct return_type_2<relational_action<Act>, A, B> {
|
---|
| 699 |
|
---|
| 700 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 701 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 702 |
|
---|
| 703 | typedef typename
|
---|
| 704 | plain_return_type_2<relational_action<Act>, plain_A, plain_B>::type type;
|
---|
| 705 | };
|
---|
| 706 |
|
---|
| 707 | // Assingment actions -----------------------------------------------
|
---|
| 708 | // return type is the type of the first argument as reference
|
---|
| 709 |
|
---|
| 710 | // note that cv-qualifiers are preserved.
|
---|
| 711 | // Yes, assignment operator can be const!
|
---|
| 712 |
|
---|
| 713 | // NOTE: this may not be true for some weird user-defined types,
|
---|
| 714 |
|
---|
| 715 | template<class A, class B, class Act>
|
---|
| 716 | struct return_type_2<arithmetic_assignment_action<Act>, A, B> {
|
---|
| 717 |
|
---|
| 718 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 719 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 720 |
|
---|
| 721 | typedef typename
|
---|
| 722 | plain_return_type_2<
|
---|
| 723 | arithmetic_assignment_action<Act>, plain_A, plain_B
|
---|
| 724 | >::type type1;
|
---|
| 725 |
|
---|
| 726 | typedef typename
|
---|
| 727 | detail::IF<
|
---|
| 728 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 729 | typename boost::add_reference<A>::type,
|
---|
| 730 | type1
|
---|
| 731 | >::RET type;
|
---|
| 732 | };
|
---|
| 733 |
|
---|
| 734 | template<class A, class B, class Act>
|
---|
| 735 | struct return_type_2<bitwise_assignment_action<Act>, A, B> {
|
---|
| 736 |
|
---|
| 737 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 738 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 739 |
|
---|
| 740 | typedef typename
|
---|
| 741 | plain_return_type_2<
|
---|
| 742 | bitwise_assignment_action<Act>, plain_A, plain_B
|
---|
| 743 | >::type type1;
|
---|
| 744 |
|
---|
| 745 | typedef typename
|
---|
| 746 | detail::IF<
|
---|
| 747 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 748 | typename boost::add_reference<A>::type,
|
---|
| 749 | type1
|
---|
| 750 | >::RET type;
|
---|
| 751 | };
|
---|
| 752 |
|
---|
| 753 | template<class A, class B>
|
---|
| 754 | struct return_type_2<other_action<assignment_action>, A, B> {
|
---|
| 755 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 756 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 757 |
|
---|
| 758 | typedef typename
|
---|
| 759 | plain_return_type_2<
|
---|
| 760 | other_action<assignment_action>, plain_A, plain_B
|
---|
| 761 | >::type type1;
|
---|
| 762 |
|
---|
| 763 | typedef typename
|
---|
| 764 | detail::IF<
|
---|
| 765 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 766 | typename boost::add_reference<A>::type,
|
---|
| 767 | type1
|
---|
| 768 | >::RET type;
|
---|
| 769 | };
|
---|
| 770 |
|
---|
| 771 | // -- other actions ----------------------------------------
|
---|
| 772 |
|
---|
| 773 | // comma action ----------------------------------
|
---|
| 774 | // Note: this may not be true for some weird user-defined types,
|
---|
| 775 |
|
---|
| 776 | // NOTE! This only tries the plain_return_type_2 layer and gives
|
---|
| 777 | // detail::unspecified as default. If no such specialization is found, the
|
---|
| 778 | // type rule in the spcecialization of the return_type_2_prot is used
|
---|
| 779 | // to give the type of the right argument (which can be a reference too)
|
---|
| 780 | // (The built in operator, can return a l- or rvalue).
|
---|
| 781 | template<class A, class B>
|
---|
| 782 | struct return_type_2<other_action<comma_action>, A, B> {
|
---|
| 783 |
|
---|
| 784 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 785 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 786 |
|
---|
| 787 | typedef typename
|
---|
| 788 | plain_return_type_2<
|
---|
| 789 | other_action<comma_action>, plain_A, plain_B
|
---|
| 790 | >::type type;
|
---|
| 791 | };
|
---|
| 792 |
|
---|
| 793 | // subscript action -----------------------------------------------
|
---|
| 794 |
|
---|
| 795 |
|
---|
| 796 | namespace detail {
|
---|
| 797 | // A and B are nonreference types
|
---|
| 798 | template <class A, class B> struct subscript_type {
|
---|
| 799 | typedef detail::unspecified type;
|
---|
| 800 | };
|
---|
| 801 |
|
---|
| 802 | template <class A, class B> struct subscript_type<A*, B> {
|
---|
| 803 | typedef A& type;
|
---|
| 804 | };
|
---|
| 805 | template <class A, class B> struct subscript_type<A* const, B> {
|
---|
| 806 | typedef A& type;
|
---|
| 807 | };
|
---|
| 808 | template <class A, class B> struct subscript_type<A* volatile, B> {
|
---|
| 809 | typedef A& type;
|
---|
| 810 | };
|
---|
| 811 | template <class A, class B> struct subscript_type<A* const volatile, B> {
|
---|
| 812 | typedef A& type;
|
---|
| 813 | };
|
---|
| 814 |
|
---|
| 815 |
|
---|
| 816 | template<class A, class B, int N> struct subscript_type<A[N], B> {
|
---|
| 817 | typedef A& type;
|
---|
| 818 | };
|
---|
| 819 |
|
---|
| 820 | // these 3 specializations are needed to make gcc <3 happy
|
---|
| 821 | template<class A, class B, int N> struct subscript_type<const A[N], B> {
|
---|
| 822 | typedef const A& type;
|
---|
| 823 | };
|
---|
| 824 | template<class A, class B, int N> struct subscript_type<volatile A[N], B> {
|
---|
| 825 | typedef volatile A& type;
|
---|
| 826 | };
|
---|
| 827 | template<class A, class B, int N> struct subscript_type<const volatile A[N], B> {
|
---|
| 828 | typedef const volatile A& type;
|
---|
| 829 | };
|
---|
| 830 |
|
---|
| 831 | } // end detail
|
---|
| 832 |
|
---|
| 833 | template<class A, class B>
|
---|
| 834 | struct return_type_2<other_action<subscript_action>, A, B> {
|
---|
| 835 |
|
---|
| 836 | typedef typename detail::remove_reference_and_cv<A>::type plain_A;
|
---|
| 837 | typedef typename detail::remove_reference_and_cv<B>::type plain_B;
|
---|
| 838 |
|
---|
| 839 | typedef typename boost::remove_reference<A>::type nonref_A;
|
---|
| 840 | typedef typename boost::remove_reference<B>::type nonref_B;
|
---|
| 841 |
|
---|
| 842 | typedef typename
|
---|
| 843 | plain_return_type_2<
|
---|
| 844 | other_action<subscript_action>, plain_A, plain_B
|
---|
| 845 | >::type type1;
|
---|
| 846 |
|
---|
| 847 | typedef typename
|
---|
| 848 | detail::IF_type<
|
---|
| 849 | boost::is_same<type1, detail::unspecified>::value,
|
---|
| 850 | detail::subscript_type<nonref_A, nonref_B>,
|
---|
| 851 | plain_return_type_2<other_action<subscript_action>, plain_A, plain_B>
|
---|
| 852 | >::type type;
|
---|
| 853 |
|
---|
| 854 | };
|
---|
| 855 |
|
---|
| 856 |
|
---|
| 857 | } // namespace lambda
|
---|
| 858 | } // namespace boost
|
---|
| 859 |
|
---|
| 860 |
|
---|
| 861 | // Forward declarations are incompatible with the libstdc++ debug mode.
|
---|
| 862 | #if BOOST_WORKAROUND(__GNUC__, >= 3) && _GLIBCXX_DEBUG
|
---|
| 863 | #include <string>
|
---|
| 864 | #include <vector>
|
---|
| 865 | #include <map>
|
---|
| 866 | #include <deque>
|
---|
| 867 | #else
|
---|
| 868 |
|
---|
| 869 | // The GCC 2.95.x uses a non-conformant deque
|
---|
| 870 | #if BOOST_WORKAROUND(__GNUC__, == 2) && __GNUC_MINOR__ <= 96
|
---|
| 871 | #include <deque>
|
---|
| 872 | #else
|
---|
| 873 |
|
---|
| 874 | namespace std {
|
---|
| 875 | template <class T, class Allocator> class deque;
|
---|
| 876 | }
|
---|
| 877 |
|
---|
| 878 | #endif
|
---|
| 879 |
|
---|
| 880 | namespace std {
|
---|
| 881 | template <class Char, class Traits, class Allocator> class basic_string;
|
---|
| 882 | template <class T, class Allocator> class vector;
|
---|
| 883 | template <class Key, class T, class Cmp, class Allocator> class map;
|
---|
| 884 | template <class Key, class T, class Cmp, class Allocator> class multimap;
|
---|
| 885 | }
|
---|
| 886 |
|
---|
| 887 | #endif
|
---|
| 888 |
|
---|
| 889 |
|
---|
| 890 |
|
---|
| 891 | namespace boost {
|
---|
| 892 | namespace lambda {
|
---|
| 893 |
|
---|
| 894 | template<class Key, class T, class Cmp, class Allocator, class B>
|
---|
| 895 | struct plain_return_type_2<other_action<subscript_action>, std::map<Key, T, Cmp, Allocator>, B> {
|
---|
| 896 | typedef T& type;
|
---|
| 897 | // T == std::map<Key, T, Cmp, Allocator>::mapped_type;
|
---|
| 898 | };
|
---|
| 899 |
|
---|
| 900 | template<class Key, class T, class Cmp, class Allocator, class B>
|
---|
| 901 | struct plain_return_type_2<other_action<subscript_action>, std::multimap<Key, T, Cmp, Allocator>, B> {
|
---|
| 902 | typedef T& type;
|
---|
| 903 | // T == std::map<Key, T, Cmp, Allocator>::mapped_type;
|
---|
| 904 | };
|
---|
| 905 |
|
---|
| 906 | // deque
|
---|
| 907 | template<class T, class Allocator, class B>
|
---|
| 908 | struct plain_return_type_2<other_action<subscript_action>, std::deque<T, Allocator>, B> {
|
---|
| 909 | typedef typename std::deque<T, Allocator>::reference type;
|
---|
| 910 | };
|
---|
| 911 | template<class T, class Allocator, class B>
|
---|
| 912 | struct plain_return_type_2<other_action<subscript_action>, const std::deque<T, Allocator>, B> {
|
---|
| 913 | typedef typename std::deque<T, Allocator>::const_reference type;
|
---|
| 914 | };
|
---|
| 915 |
|
---|
| 916 | // vector
|
---|
| 917 | template<class T, class Allocator, class B>
|
---|
| 918 | struct plain_return_type_2<other_action<subscript_action>, std::vector<T, Allocator>, B> {
|
---|
| 919 | typedef typename std::vector<T, Allocator>::reference type;
|
---|
| 920 | };
|
---|
| 921 | template<class T, class Allocator, class B>
|
---|
| 922 | struct plain_return_type_2<other_action<subscript_action>, const std::vector<T, Allocator>, B> {
|
---|
| 923 | typedef typename std::vector<T, Allocator>::const_reference type;
|
---|
| 924 | };
|
---|
| 925 |
|
---|
| 926 | // basic_string
|
---|
| 927 | template<class Char, class Traits, class Allocator, class B>
|
---|
| 928 | struct plain_return_type_2<other_action<subscript_action>, std::basic_string<Char, Traits, Allocator>, B> {
|
---|
| 929 | typedef typename std::basic_string<Char, Traits, Allocator>::reference type;
|
---|
| 930 | };
|
---|
| 931 | template<class Char, class Traits, class Allocator, class B>
|
---|
| 932 | struct plain_return_type_2<other_action<subscript_action>, const std::basic_string<Char, Traits, Allocator>, B> {
|
---|
| 933 | typedef typename std::basic_string<Char, Traits, Allocator>::const_reference type;
|
---|
| 934 | };
|
---|
| 935 |
|
---|
| 936 |
|
---|
| 937 | } // namespace lambda
|
---|
| 938 | } // namespace boost
|
---|
| 939 |
|
---|
| 940 | #endif
|
---|
| 941 |
|
---|
| 942 |
|
---|