ceph/src/boost/boost/detail/call_traits.hpp

   1 //  (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
   2 //  Use, modification and distribution are subject to the Boost Software License,
   3 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   4 //  http://www.boost.org/LICENSE_1_0.txt).
   5 //
   6 //  See http://www.boost.org/libs/utility for most recent version including documentation.
   7
   8 // call_traits: defines typedefs for function usage
   9 // (see libs/utility/call_traits.htm)
  10
  11 /* Release notes:
  12    23rd July 2000:
  13       Fixed array specialization. (JM)
  14       Added Borland specific fixes for reference types
  15       (issue raised by Steve Cleary).
  16 */
  17
  18 #ifndef BOOST_DETAIL_CALL_TRAITS_HPP
  19 #define BOOST_DETAIL_CALL_TRAITS_HPP
  20
  21 #ifndef BOOST_CONFIG_HPP
  22 #include <boost/config.hpp>
  23 #endif
  24 #include <cstddef>
  25
  26 #include <boost/type_traits/is_arithmetic.hpp>
  27 #include <boost/type_traits/is_enum.hpp>
  28 #include <boost/type_traits/is_pointer.hpp>
  29 #include <boost/detail/workaround.hpp>
  30
  31 namespace boost{
  32
  33 namespace detail{
  34
  35 template <typename T, bool small_>
  36 struct ct_imp2
  37 {
  38    typedef const T& param_type;
  39 };
  40
  41 template <typename T>
  42 struct ct_imp2<T, true>
  43 {
  44    typedef const T param_type;
  45 };
  46
  47 template <typename T, bool isp, bool b1, bool b2>
  48 struct ct_imp
  49 {
  50    typedef const T& param_type;
  51 };
  52
  53 template <typename T, bool isp, bool b2>
  54 struct ct_imp<T, isp, true, b2>
  55 {
  56    typedef typename ct_imp2<T, sizeof(T) <= sizeof(void*)>::param_type param_type;
  57 };
  58
  59 template <typename T, bool isp, bool b1>
  60 struct ct_imp<T, isp, b1, true>
  61 {
  62    typedef typename ct_imp2<T, sizeof(T) <= sizeof(void*)>::param_type param_type;
  63 };
  64
  65 template <typename T, bool b1, bool b2>
  66 struct ct_imp<T, true, b1, b2>
  67 {
  68    typedef const T param_type;
  69 };
  70
  71 }
  72
  73 template <typename T>
  74 struct call_traits
  75 {
  76 public:
  77    typedef T value_type;
  78    typedef T& reference;
  79    typedef const T& const_reference;
  80    //
  81    // C++ Builder workaround: we should be able to define a compile time
  82    // constant and pass that as a single template parameter to ct_imp<T,bool>,
  83    // however compiler bugs prevent this - instead pass three bool's to
  84    // ct_imp<T,bool,bool,bool> and add an extra partial specialisation
  85    // of ct_imp to handle the logic. (JM)
  86    typedef typename boost::detail::ct_imp<
  87       T,
  88       ::boost::is_pointer<T>::value,
  89       ::boost::is_arithmetic<T>::value,
  90       ::boost::is_enum<T>::value
  91    >::param_type param_type;
  92 };
  93
  94 template <typename T>
  95 struct call_traits<T&>
  96 {
  97    typedef T& value_type;
  98    typedef T& reference;
  99    typedef const T& const_reference;
 100    typedef T& param_type;  // hh removed const
 101 };
 102
 103 #if BOOST_WORKAROUND( __BORLANDC__,  < 0x5A0 )
 104 // these are illegal specialisations; cv-qualifies applied to
 105 // references have no effect according to [8.3.2p1],
 106 // C++ Builder requires them though as it treats cv-qualified
 107 // references as distinct types...
 108 template <typename T>
 109 struct call_traits<T&const>
 110 {
 111    typedef T& value_type;
 112    typedef T& reference;
 113    typedef const T& const_reference;
 114    typedef T& param_type;  // hh removed const
 115 };
 116 template <typename T>
 117 struct call_traits<T&volatile>
 118 {
 119    typedef T& value_type;
 120    typedef T& reference;
 121    typedef const T& const_reference;
 122    typedef T& param_type;  // hh removed const
 123 };
 124 template <typename T>
 125 struct call_traits<T&const volatile>
 126 {
 127    typedef T& value_type;
 128    typedef T& reference;
 129    typedef const T& const_reference;
 130    typedef T& param_type;  // hh removed const
 131 };
 132
 133 template <typename T>
 134 struct call_traits< T * >
 135 {
 136    typedef T * value_type;
 137    typedef T * & reference;
 138    typedef T * const & const_reference;
 139    typedef T * const param_type;  // hh removed const
 140 };
 141 #endif
 142 #if !defined(BOOST_NO_ARRAY_TYPE_SPECIALIZATIONS)
 143 template <typename T, std::size_t N>
 144 struct call_traits<T [N]>
 145 {
 146 private:
 147    typedef T array_type[N];
 148 public:
 149    // degrades array to pointer:
 150    typedef const T* value_type;
 151    typedef array_type& reference;
 152    typedef const array_type& const_reference;
 153    typedef const T* const param_type;
 154 };
 155
 156 template <typename T, std::size_t N>
 157 struct call_traits<const T [N]>
 158 {
 159 private:
 160    typedef const T array_type[N];
 161 public:
 162    // degrades array to pointer:
 163    typedef const T* value_type;
 164    typedef array_type& reference;
 165    typedef const array_type& const_reference;
 166    typedef const T* const param_type;
 167 };
 168 #endif
 169
 170 }
 171
 172 #endif // BOOST_DETAIL_CALL_TRAITS_HPP