boost/type_traits/detail/cv_traits_impl.hpp

   1
   2 //  (C) Copyright Dave Abrahams, Steve Cleary, Beman Dawes, Howard
   3 //  Hinnant & John Maddock 2000.
   4 //  Use, modification and distribution are subject to the Boost Software License,
   5 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   6 //  http://www.boost.org/LICENSE_1_0.txt).
   7 //
   8 //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
   9
  10
  11 #ifndef BOOST_TT_DETAIL_CV_TRAITS_IMPL_HPP_INCLUDED
  12 #define BOOST_TT_DETAIL_CV_TRAITS_IMPL_HPP_INCLUDED
  13
  14 #include <boost/config.hpp>
  15 #include <boost/detail/workaround.hpp>
  16
  17 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  18
  19 // implementation helper:
  20
  21
  22 #if !(BOOST_WORKAROUND(__GNUC__,== 3) && BOOST_WORKAROUND(__GNUC_MINOR__, <= 2))
  23 namespace boost {
  24 namespace detail {
  25 #else
  26 #include <boost/type_traits/detail/yes_no_type.hpp>
  27 namespace boost {
  28 namespace type_traits {
  29 namespace gcc8503 {
  30 #endif
  31
  32 template <typename T> struct cv_traits_imp {};
  33
  34 template <typename T>
  35 struct cv_traits_imp<T*>
  36 {
  37     BOOST_STATIC_CONSTANT(bool, is_const = false);
  38     BOOST_STATIC_CONSTANT(bool, is_volatile = false);
  39     typedef T unqualified_type;
  40 };
  41
  42 template <typename T>
  43 struct cv_traits_imp<const T*>
  44 {
  45     BOOST_STATIC_CONSTANT(bool, is_const = true);
  46     BOOST_STATIC_CONSTANT(bool, is_volatile = false);
  47     typedef T unqualified_type;
  48 };
  49
  50 template <typename T>
  51 struct cv_traits_imp<volatile T*>
  52 {
  53     BOOST_STATIC_CONSTANT(bool, is_const = false);
  54     BOOST_STATIC_CONSTANT(bool, is_volatile = true);
  55     typedef T unqualified_type;
  56 };
  57
  58 template <typename T>
  59 struct cv_traits_imp<const volatile T*>
  60 {
  61     BOOST_STATIC_CONSTANT(bool, is_const = true);
  62     BOOST_STATIC_CONSTANT(bool, is_volatile = true);
  63     typedef T unqualified_type;
  64 };
  65
  66 #if BOOST_WORKAROUND(__GNUC__,== 3) && BOOST_WORKAROUND(__GNUC_MINOR__, <= 2)
  67 // We have to exclude function pointers
  68 // (see http://gcc.gnu.org/bugzilla/show_bug.cgi?8503)
  69 yes_type mini_funcptr_tester(...);
  70 no_type  mini_funcptr_tester(const volatile void*);
  71
  72 } // namespace gcc8503
  73 } // namespace type_traits
  74
  75 namespace detail {
  76
  77 // Use the implementation above for non function pointers
  78 template <typename T, unsigned Select
  79   = (unsigned)sizeof(::boost::type_traits::gcc8503::mini_funcptr_tester((T)0)) >
  80 struct cv_traits_imp : public ::boost::type_traits::gcc8503::cv_traits_imp<T> { };
  81
  82 // Functions are never cv-qualified
  83 template <typename T> struct cv_traits_imp<T*,1>
  84 {
  85     BOOST_STATIC_CONSTANT(bool, is_const = false);
  86     BOOST_STATIC_CONSTANT(bool, is_volatile = false);
  87     typedef T unqualified_type;
  88 };
  89
  90 #endif
  91
  92 } // namespace detail
  93 } // namespace boost
  94
  95 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  96
  97 #endif // BOOST_TT_DETAIL_CV_TRAITS_IMPL_HPP_INCLUDED