extl/type/traits/remove_const.h

   1 /* ///////////////////////////////////////////////////////////////////////
   2  * File:                remove_const.h
   3  *
   4  * Created:             08.02.07
   5  * Updated:             08.07.09
   6  *
   7  * Brief: remove_const traits
   8  *
   9  * [<Home>]
  10  * Copyright (c) 2008-2020, Waruqi All rights reserved.
  11  * //////////////////////////////////////////////////////////////////// */
  12 #ifndef EXTL_TYPE_TRAITS_REMOVE_CONST_H
  13 #define EXTL_TYPE_TRAITS_REMOVE_CONST_H
  14
  15 #ifndef EXTL_TYPE_TRAITS_REMOVE_CONST_SUPPORT
  16 #       error extl::remove_const is not supported by current compiler.
  17 #endif
  18
  19 /* ///////////////////////////////////////////////////////////////////////
  20  * Includes
  21  */
  22 #include "prefix.h"
  23
  24 #ifdef EXTL_TYPE_TRAITS_IS_PTR_SUPPORT
  25 #       include "is_ptr.h"
  26 #endif
  27
  28 #ifdef EXTL_TYPE_TRAITS_IS_CONST_SUPPORT
  29 #       include "is_const.h"
  30 #endif
  31
  32 #ifdef EXTL_TYPE_TRAITS_IS_VOLATILE_SUPPORT
  33 #       include "is_volatile.h"
  34 #endif
  35
  36 #ifdef EXTL_TYPE_TRAITS_IS_ARRAY_SUPPORT
  37 #       include "is_array.h"
  38 #endif
  39
  40 // only for VC 6.0,7.0,7.1
  41 #if defined(EXTL_TYPE_TRAITS_TYPE_BUFFER_SUPPORT)
  42 #       include "detail/type_buffer.h"
  43 #endif
  44
  45 /* ///////////////////////////////////////////////////////////////////////
  46  * Macros
  47  */
  48 #define EXTL_REMOVE_CONST(src_type)     EXTL_MODIFY_TYPE(remove_const, src_type)
  49
  50 /* ///////////////////////////////////////////////////////////////////////
  51  * ::extl namespace
  52  */
  53 EXTL_BEGIN_NAMESPACE
  54
  55 #ifdef EXTL_TYPE_TRAITS_SUPPORT
  56
  57 #       ifdef EXTL_TEMPLATE_PARTIAL_SPEC_SUPPORT
  58
  59         EXTL_TYPE_TRAIT_DEF_1(remove_const_impl, T)
  60         EXTL_TYPE_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, remove_const_impl, T*, T)
  61         EXTL_TYPE_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, remove_const_impl, const T*, T)
  62         EXTL_TYPE_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, remove_const_impl, volatile T*, volatile T)
  63         EXTL_TYPE_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, remove_const_impl, const volatile T*, volatile T)
  64
  65         EXTL_TYPE_TRAIT_DEF_1(remove_const, typename_type_k remove_const_impl<T*>::type)
  66         EXTL_TYPE_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, remove_const, T&, T&)
  67
  68 #       ifdef EXTL_TEMPLATE_PARTIAL_SPEC_ARRAY_TYPE_SUPPORT
  69         EXTL_TYPE_TRAIT_PARTIAL_SPEC_TO_ARRAY_1_2(typename_param_k T, e_size_t N, remove_const, T const[N], T type[N])
  70         EXTL_TYPE_TRAIT_PARTIAL_SPEC_TO_ARRAY_1_2(typename_param_k T, e_size_t N, remove_const, T const volatile [N], T volatile type[N])
  71 #       endif
  72
  73 #       elif EXTL_WORKAROUND_MSVC(<=, 1300)
  74                 /* //////////////////////////////////////////////////////////////////// */
  75                 template< e_bool_t is_ptr, e_bool_t is_array, e_bool_t is_const, e_bool_t is_volatile >
  76                 struct remove_const_helper
  77                 {
  78                         template< typename_param_k T , typename_param_k ID >
  79                         struct result
  80                         {
  81                                 typedef T type;
  82                         };
  83                         template< typename_param_k T >
  84             struct transform_type
  85                         {
  86                 typedef T type;
  87             };
  88                 };
  89                 EXTL_TEMPLATE_SPECIALISATION    // const
  90                 struct remove_const_helper< e_false_v, e_false_v, e_true_v , e_false_v >
  91                 {
  92                         template< typename_param_k T, typename_param_k ID >
  93                         struct result
  94                         {
  95                                 template< typename_param_k U >
  96                                 static save_type<U, ID> test(U const&(*)());
  97                                 static save_type<T, ID> test(...);
  98                                 EXTL_STATIC_MEMBER_CONST(e_bool_t, value = sizeof( test( (T(*)())(NULL) ) ));
  99                                 typedef typename_type_k type_buffer<ID>::result::type type;
 100                         };
 101                         template< typename_param_k T >
 102             struct transform_type
 103                         {
 104                 typedef T& type;        // exclude const&
 105             };
 106                 };
 107
 108                 EXTL_TEMPLATE_SPECIALISATION    // cv
 109                 struct remove_const_helper< e_false_v, e_false_v, e_true_v , e_true_v >
 110                 {
 111                         template< typename_param_k T, typename_param_k ID >
 112                         struct result
 113                         {
 114                                 template< typename_param_k U >
 115                                 static save_type<U volatile, ID> test(U const volatile&(*)());
 116                                 static save_type<T, ID> test(...);
 117                                 EXTL_STATIC_MEMBER_CONST(e_bool_t, value = sizeof( test( (T(*)())(NULL) ) ));
 118                                 typedef typename_type_k type_buffer<ID>::result::type type;
 119                         };
 120                         template< typename_param_k T >
 121             struct transform_type
 122                         {
 123                 typedef T& type;        // exclude const&
 124             };
 125                 };
 126
 127                 EXTL_TEMPLATE_SPECIALISATION    // const ptr
 128                 struct remove_const_helper< e_true_v, e_false_v, e_true_v , e_false_v >
 129                 {
 130                         template< typename_param_k T, typename_param_k ID >
 131                         struct result
 132                         {
 133                                 template< typename_param_k U >
 134                                 static save_type<U, ID> test(void(*)(U const[]));
 135                                 static save_type<T, ID> test(...);
 136                                 EXTL_STATIC_MEMBER_CONST(e_bool_t, value = sizeof( test( (void(*)(T))(NULL) ) ));
 137                                 typedef typename_type_k type_buffer<ID>::result::type type;
 138                         };
 139                         template< typename_param_k T >
 140             struct transform_type
 141                         {
 142                 typedef T type[];
 143             };
 144                 };
 145
 146                 EXTL_TEMPLATE_SPECIALISATION    // cv ptr
 147                 struct remove_const_helper< e_true_v, e_false_v, e_true_v , e_true_v >
 148                 {
 149                         template< typename_param_k T, typename_param_k ID >
 150                         struct result
 151                         {
 152                                 template< typename_param_k U >
 153                                 static save_type<U volatile, ID> test(void(*)(U const volatile[]));
 154                                 static save_type<T, ID> test(...);
 155                                 EXTL_STATIC_MEMBER_CONST(e_bool_t, value = sizeof( test( (void(*)(T))(NULL) ) ));
 156                                 typedef typename_type_k type_buffer<ID>::result::type type;
 157                         };
 158                         template< typename_param_k T >
 159             struct transform_type
 160                         {
 161                 typedef T type[];
 162             };
 163                 };
 164
 165                 EXTL_TEMPLATE_SPECIALISATION    // const array
 166                 struct remove_const_helper< e_false_v, e_true_v, e_true_v , e_false_v >
 167                 {
 168                         template< typename_param_k T, typename_param_k ID >
 169                         struct result
 170                         {
 171                                 EXTL_STATIC_MEMBER_CONST(e_size_t, num = (sizeof(T)/sizeof((*((T*)NULL))[0])) );
 172
 173                                 template< typename_param_k U >
 174                                 static save_type<U[num], ID> test(void(*)(U const[]));
 175                                 static save_type<T, ID> test(...);
 176                                 EXTL_STATIC_MEMBER_CONST(e_bool_t, value = sizeof( test( (void(*)(T))(NULL) ) ));
 177                                 typedef typename_type_k type_buffer<ID>::result::type type;
 178                         };
 179                         template< typename_param_k T >
 180             struct transform_type
 181                         {
 182                 typedef T type;
 183             };
 184                 };
 185
 186                 EXTL_TEMPLATE_SPECIALISATION    // cv array
 187                 struct remove_const_helper< e_false_v, e_true_v, e_true_v , e_true_v >
 188                 {
 189                         template< typename_param_k T, typename_param_k ID >
 190                         struct result
 191                         {
 192                                 EXTL_STATIC_MEMBER_CONST(e_size_t, num = (sizeof(T)/sizeof((*((T*)NULL))[0])) );
 193
 194                                 template< typename_param_k U >
 195                                 static save_type<U volatile[num], ID> test(void(*)(U const volatile[]));
 196                                 static save_type<T, ID> test(...);
 197                                 EXTL_STATIC_MEMBER_CONST(e_bool_t, value = sizeof( test( (void(*)(T))(NULL) ) ));
 198                                 typedef typename_type_k type_buffer<ID>::result::type type;
 199                         };
 200                         template< typename_param_k T >
 201             struct transform_type
 202                         {
 203                 typedef T type;
 204             };
 205                 };
 206
 207                 template< typename_param_k T>
 208                 struct remove_const_impl
 209                 {
 210                         typedef remove_const_helper     <       (is_ptr<T>::value)
 211                                                                                 ,       (is_array<T>::value)
 212                                                                                 ,       (is_const<T>::value)
 213                                                                                 ,       (is_volatile<T>::value)
 214                                                                                 >       remove_const_type;
 215
 216                         typedef typename_type_k remove_const_type::template_qual_k result<
 217                                                                                 typename_type_k remove_const_type::template_qual_k transform_type<T>::type
 218                                                                         ,       remove_const_impl<T>
 219                                                                         >::type type;
 220
 221                 };
 222
 223                 EXTL_TYPE_TRAIT_DEF_1(remove_const, typename_type_k remove_const_impl<T>::type)
 224
 225 #       endif
 226
 227 /* ///////////////////////////////////////////////////////////////////////
 228  * Unit-testing
 229  */
 230 #       ifdef   EXTL_TYPE_TRAITS_TEST_ENABLE
 231 #               include "unit_test/remove_const_test.h"
 232 #       endif
 233 #endif
 234 /* ///////////////////////////////////////////////////////////////////////
 235  * ::extl namespace
 236  */
 237 EXTL_END_NAMESPACE
 238
 239 /* //////////////////////////////////////////////////////////////////// */
 240 #endif  /* EXTL_TYPE_TRAITS_REMOVE_CONST_H */
 241 /* //////////////////////////////////////////////////////////////////// */