boost/boost/type_traits/add_reference.hpp

   1
   2 // (C) Copyright Steve Cleary, Beman Dawes, Howard Hinnant & John Maddock 2000.
   3 // Permission to copy, use, modify, sell and distribute this software is
   4 // granted provided this copyright notice appears in all copies. This software
   5 // is provided "as is" without express or implied warranty, and with no claim
   6 // as to its suitability for any purpose.
   7 //
   8 // See http://www.boost.org for most recent version including documentation.
   9
  10 #ifndef BOOST_TT_ADD_REFERENCE_HPP_INCLUDED
  11 #define BOOST_TT_ADD_REFERENCE_HPP_INCLUDED
  12
  13 #include "boost/type_traits/is_reference.hpp"
  14 #include "boost/config.hpp"
  15
  16 // should be the last #include
  17 #include "boost/type_traits/detail/type_trait_def.hpp"
  18
  19 namespace boost {
  20
  21 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  22
  23 BOOST_TT_AUX_TYPE_TRAIT_DEF1(add_reference,T,T&)
  24 BOOST_TT_AUX_TYPE_TRAIT_PARTIAL_SPEC1_1(typename T,add_reference,T&,T&)
  25
  26 #elif defined(BOOST_MSVC6_MEMBER_TEMPLATES)
  27
  28 namespace detail {
  29
  30 template <bool x>
  31 struct reference_adder
  32 {
  33     template <typename T> struct result_
  34     {
  35         typedef T& type;
  36     };
  37 };
  38
  39 template <>
  40 struct reference_adder<true>
  41 {
  42     template <typename T> struct result_
  43     {
  44         typedef T type;
  45     };
  46 };
  47
  48 template <typename T>
  49 struct add_reference_impl
  50 {
  51     typedef typename reference_adder<
  52           ::boost::is_reference<T>::value
  53         >::template result_<T> result;
  54
  55     typedef typename result::type type;
  56 };
  57
  58 } // namespace detail
  59
  60 BOOST_TT_AUX_TYPE_TRAIT_DEF1(add_reference,T,typename detail::add_reference_impl<T>::type)
  61
  62 #else
  63
  64 BOOST_TT_AUX_TYPE_TRAIT_DEF1(add_reference,T,T&)
  65
  66 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  67
  68 //
  69 // these full specialisations are always required:
  70 BOOST_TT_AUX_TYPE_TRAIT_SPEC1(add_reference,void,void)
  71 #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
  72 BOOST_TT_AUX_TYPE_TRAIT_SPEC1(add_reference,void const,void const)
  73 BOOST_TT_AUX_TYPE_TRAIT_SPEC1(add_reference,void volatile,void volatile)
  74 BOOST_TT_AUX_TYPE_TRAIT_SPEC1(add_reference,void const volatile,void const volatile)
  75 #endif
  76
  77 } // namespace boost
  78
  79 #include "boost/type_traits/detail/type_trait_undef.hpp"
  80
  81 #endif // BOOST_TT_ADD_REFERENCE_HPP_INCLUDED