extl/type/traits/is_ref.h

   1 /* ///////////////////////////////////////////////////////////////////////
   2  * File:                is_ref.h
   3  *
   4  * Created:             08.02.17
   5  * Updated:             08.07.09
   6  *
   7  * Brief: is_ref traits
   8  *
   9  * [<Home>]
  10  * Copyright (c) 2008-2020, Waruqi All rights reserved.
  11  * //////////////////////////////////////////////////////////////////// */
  12 #ifndef EXTL_TYPE_TRAITS_IS_REF_H
  13 #define EXTL_TYPE_TRAITS_IS_REF_H
  14
  15 #ifndef EXTL_TYPE_TRAITS_IS_REF_SUPPORT
  16 #       error extl::is_ref is not supported by current compiler.
  17 #endif
  18
  19 /* ///////////////////////////////////////////////////////////////////////
  20  * Includes
  21  */
  22 #include "prefix.h"
  23 #include "logical_op.h"
  24
  25 #ifndef EXTL_TEMPLATE_PARTIAL_SPEC_SUPPORT // for VC6.0 ...
  26 #       ifdef EXTL_TYPE_TRAITS_IS_FUNC_SUPPORT
  27 #               include "is_func.h"
  28 #       endif
  29 #endif
  30
  31 /* ///////////////////////////////////////////////////////////////////////
  32  * Macros
  33  */
  34 #define EXTL_MUST_BE_REF(type)                  EXTL_MUST_BE_(is_ref, type)
  35 #define EXTL_MUST_BE_CV_REF(type)               EXTL_MUST_BE_CV_(is_ref, type)
  36 #define EXTL_MUST_NOT_BE_REF(type)              EXTL_MUST_NOT_BE_(is_ref, type)
  37 #define EXTL_MUST_NOT_BE_CV_REF(type)   EXTL_MUST_NOT_BE_CV_(is_ref, type)
  38
  39 /* ///////////////////////////////////////////////////////////////////////
  40  * ::extl namespace
  41  */
  42 EXTL_BEGIN_NAMESPACE
  43
  44 #ifdef EXTL_TYPE_TRAITS_SUPPORT
  45
  46 #       ifdef EXTL_TEMPLATE_PARTIAL_SPEC_SUPPORT
  47
  48         EXTL_BOOL_TRAIT_DEF_1(is_ref, e_false_v)
  49         EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T&, e_true_v)
  50
  51 #               if defined(EXTL_COMPILER_IS_BORLAND) && !defined(__COMO__) && (__BORLANDC__ < 0x600)
  52                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T& const, e_true_v)
  53                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T& volatile, e_true_v)
  54                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T& const volatile, e_true_v)
  55 #               endif
  56
  57 #               if defined(EXTL_COMPILER_IS_GCC) && (__GNUC__ < 3)
  58                 // these allow us to work around illegally cv-qualified reference types
  59                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T const , is_ref<T>::value)
  60                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T volatile , is_ref<T>::value)
  61                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_1(typename_param_k T, is_ref, T const volatile , is_ref<T>::value)
  62                 // However, the above specializations confuse gcc 2.96 unless we also
  63                 // supply these specializations for array types
  64                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_2(typename_param_k T, e_size_t N, is_ref, T[N], e_false_v)
  65                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_2(typename_param_k T, e_size_t N, is_ref, const T[N], e_false_v)
  66                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_2(typename_param_k T, e_size_t N, is_ref, volatile T[N], e_false_v)
  67                 EXTL_BOOL_TRAIT_PARTIAL_SPEC_1_2(typename_param_k T, e_size_t N, is_ref, const volatile T[N], e_false_v)
  68 #               endif
  69 #       else    /* !defined(EXTL_TEMPLATE_PARTIAL_SPEC_SUPPORT) */
  70
  71         char EXTL_CDECL is_ref_helper1(...);
  72         // retrun type: T&(*)(type_wrap<T>)
  73         template <typename_param_k T>
  74         T&(* is_ref_helper1(type_wrap<T>))(type_wrap<T>);
  75
  76         yes_type EXTL_CDECL is_ref_helper2(...);
  77         template <typename_param_k T>
  78         no_type is_ref_helper2(T&(*)(type_wrap<T>)); // note: cannot exclude function type
  79
  80         //EXTL_BOOL_TRAIT_DEF_1(is_ref, sizeof(is_ref_helper2(is_ref_helper1(type_wrap<T>()))) == sizeof(yes_type))
  81         EXTL_BOOL_TRAIT_DEF_1(is_ref, (op_and   <       (sizeof(is_ref_helper2(is_ref_helper1(type_wrap<T>()))) == sizeof(yes_type))
  82                                                                                         ,       (op_not<(is_func<T>::value)>::value) /* exclude function type */
  83                                                                                         >::value))
  84
  85         EXTL_BOOL_TRAIT_SPEC_1(is_ref, void, e_false_v)
  86 #               ifdef EXTL_CV_VOID_SPEC_SUPPORT
  87                 EXTL_BOOL_TRAIT_SPEC_1(is_ref, void const, e_false_v)
  88                 EXTL_BOOL_TRAIT_SPEC_1(is_ref, void volatile, e_false_v)
  89                 EXTL_BOOL_TRAIT_SPEC_1(is_ref, void const volatile, e_false_v)
  90 #               endif
  91
  92 #       endif   /* EXTL_TEMPLATE_PARTIAL_SPEC_SUPPORT */
  93
  94 /* ///////////////////////////////////////////////////////////////////////
  95  * Unit-testing
  96  */
  97 #       ifdef   EXTL_TYPE_TRAITS_TEST_ENABLE
  98 #               include "unit_test/is_ref_test.h"
  99 #       endif
 100 #endif
 101
 102 /* ///////////////////////////////////////////////////////////////////////
 103  * ::extl namespace
 104  */
 105 EXTL_END_NAMESPACE
 106
 107 /* //////////////////////////////////////////////////////////////////// */
 108 #endif  /* EXTL_TYPE_TRAITS_IS_REF_H */
 109 /* //////////////////////////////////////////////////////////////////// */