1 
2 // Copyright (C) 2005 Igor Chesnokov, mailto:ichesnokov@gmail.com (VC 6.5,VC 7.1 + counter code)
3 // Copyright (C) 2005-2007 Peder Holt (VC 7.0 + framework)
4 // Copyright (C) 2006 Steven Watanabe (VC 8.0)
5 
6 // Use, modification and distribution is subject to the Boost Software
7 // License, Version 1.0. (http://www.boost.org/LICENSE_1_0.txt)
8 
9 #ifndef BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED
10 # define BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED
11 
12 # include <boost/config.hpp>
13 # include <boost/config/workaround.hpp>
14 # include <boost/typeof/constant.hpp>
15 # include <boost/type_traits/enable_if.hpp>
16 # include <boost/type_traits/is_function.hpp>
17 
18 # include <typeinfo>
19 
20 namespace boost
21 {
22     namespace type_of
23     {
24 
25         //Compile time constant code
26 # if defined(_MSC_EXTENSIONS)
27         template<int N> struct the_counter;
28 
29         template<typename T,int N = 5/*for similarity*/>
30         struct encode_counter
31         {
__if_existsboost::type_of::encode_counter32             __if_exists(the_counter<N + 256>)
33             {
34                 BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 257>::count));
35             }
__if_not_existsboost::type_of::encode_counter36             __if_not_exists(the_counter<N + 256>)
37             {
38                 __if_exists(the_counter<N + 64>)
39                 {
40                     BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 65>::count));
41                 }
42                 __if_not_exists(the_counter<N + 64>)
43                 {
44                     __if_exists(the_counter<N + 16>)
45                     {
46                         BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 17>::count));
47                     }
48                     __if_not_exists(the_counter<N + 16>)
49                     {
50                         __if_exists(the_counter<N + 4>)
51                         {
52                             BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 5>::count));
53                         }
54                         __if_not_exists(the_counter<N + 4>)
55                         {
56                             __if_exists(the_counter<N>)
57                             {
58                                 BOOST_STATIC_CONSTANT(unsigned,count=(encode_counter<T,N + 1>::count));
59                             }
60                             __if_not_exists(the_counter<N>)
61                             {
62                                 BOOST_STATIC_CONSTANT(unsigned,count=N);
63                                 typedef the_counter<N> type;
64                             }
65                         }
66                     }
67                 }
68             }
69         };
70 
71 # define BOOST_TYPEOF_INDEX(T) (encode_counter<T>::count)
72 # define BOOST_TYPEOF_NEXT_INDEX(next)
73 # else
74         template<int N> struct encode_counter : encode_counter<N - 1> {};
75         template<> struct encode_counter<0> {};
76 
77         //Need to default to a larger value than 4, as due to MSVC's ETI errors. (sizeof(int)==4)
78         char (*encode_index(...))[5];
79 
80 # define BOOST_TYPEOF_INDEX(T) (sizeof(*boost::type_of::encode_index((boost::type_of::encode_counter<1005>*)0)))
81 # define BOOST_TYPEOF_NEXT_INDEX(next) friend char (*encode_index(encode_counter<next>*))[next];
82 # endif
83 
84         //Typeof code
85 
86 # if BOOST_WORKAROUND(BOOST_MSVC,>=1400)
87         struct msvc_extract_type_default_param {};
88 
89         template<typename ID, typename T = msvc_extract_type_default_param>
90         struct msvc_extract_type;
91 
92         template<typename ID>
93         struct msvc_extract_type<ID, msvc_extract_type_default_param> {
94             template<bool>
95             struct id2type_impl;
96 
97             typedef id2type_impl<true> id2type;
98         };
99 
100         template<typename ID, typename T>
101         struct msvc_extract_type : msvc_extract_type<ID,msvc_extract_type_default_param>
102         {
103             template<>
104             struct id2type_impl<true>  //VC8.0 specific bugfeature
105             {
106                 typedef T type;
107             };
108             template<bool>
109             struct id2type_impl;
110 
111             typedef id2type_impl<true> id2type;
112         };
113 
114         template<typename T, typename ID>
115         struct msvc_register_type : msvc_extract_type<ID, T>
116         {
117         };
118 # else
119         template<typename ID>
120         struct msvc_extract_type
121         {
122             struct id2type;
123         };
124 
125         template<typename T, typename ID>
126         struct msvc_register_type : msvc_extract_type<ID>
127         {
128             typedef msvc_extract_type<ID> base_type;
129             struct base_type::id2type // This uses nice VC6.5 and VC7.1 bugfeature
130             {
131                 typedef T type;
132             };
133         };
134 # endif
135 
136         template<int ID>
137         struct msvc_typeid_wrapper {
138             typedef typename msvc_extract_type<constant<int,ID> >::id2type id2type;
139             typedef typename id2type::type type;
140         };
141         //Workaround for ETI-bug for VC6 and VC7
142         template<>
143         struct msvc_typeid_wrapper<1> {
144             typedef msvc_typeid_wrapper<1> type;
145         };
146         //Workaround for ETI-bug for VC7.1
147         template<>
148         struct msvc_typeid_wrapper<4> {
149             typedef msvc_typeid_wrapper<4> type;
150         };
151 
152         //Tie it all together
153         template<typename T>
154         struct encode_type
155         {
156             //Get the next available compile time constants index
157             BOOST_STATIC_CONSTANT(unsigned,value=BOOST_TYPEOF_INDEX(T));
158             //Instantiate the template
159             typedef typename msvc_register_type<T,constant<int,value> >::id2type type;
160             //Set the next compile time constants index
161             BOOST_STATIC_CONSTANT(unsigned,next=value+1);
162             //Increment the compile time constant (only needed when extensions are not active
163             BOOST_TYPEOF_NEXT_INDEX(next);
164         };
165 
166         template<class T>
167         struct sizer
168         {
169             typedef char(*type)[encode_type<T>::value];
170         };
171         template<typename T> typename enable_if_<
172             !is_function<T>::value,
173             typename sizer<T>::type>::type encode_start(T const&);
174 
175         template<typename T> typename enable_if_<
176             is_function<T>::value,
177             typename sizer<T>::type>::type encode_start(T&);
178         template<typename Organizer, typename T>
179         msvc_register_type<T,Organizer> typeof_register_type(const T&,Organizer* =0);
180 
181 # define BOOST_TYPEOF(expr) \
182     boost::type_of::msvc_typeid_wrapper<sizeof(*boost::type_of::encode_start(expr))>::type
183 
184 # define BOOST_TYPEOF_TPL(expr) typename BOOST_TYPEOF(expr)
185 
186 # define BOOST_TYPEOF_NESTED_TYPEDEF_TPL(name,expr) \
187     struct name {\
188         enum {_typeof_register_value=sizeof(boost::type_of::typeof_register_type<name>(expr))};\
189         typedef typename boost::type_of::msvc_extract_type<name>::id2type id2type;\
190         typedef typename id2type::type type;\
191     };
192 
193 # define BOOST_TYPEOF_NESTED_TYPEDEF(name,expr) \
194     struct name {\
195         enum {_typeof_register_value=sizeof(boost::type_of::typeof_register_type<name>(expr))};\
196         typedef boost::type_of::msvc_extract_type<name>::id2type id2type;\
197         typedef id2type::type type;\
198     };
199 
200     }
201 }
202 
203 #endif//BOOST_TYPEOF_MSVC_TYPEOF_IMPL_HPP_INCLUDED
204