Chris@16: // Copyright David Abrahams 2003. Use, modification and distribution is
Chris@16: // subject to the Boost Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef IS_READABLE_ITERATOR_DWA2003112_HPP
Chris@16: # define IS_READABLE_ITERATOR_DWA2003112_HPP
Chris@16: 
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/detail/iterator.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/detail/bool_trait_def.hpp>
Chris@16: #include <boost/iterator/detail/any_conversion_eater.hpp>
Chris@16: 
Chris@16: // should be the last #include
Chris@16: #include <boost/iterator/detail/config_def.hpp>
Chris@16: 
Chris@16: #ifndef BOOST_NO_IS_CONVERTIBLE
Chris@16: 
Chris@16: namespace boost {
Chris@101: 
Chris@101: namespace iterators {
Chris@101: 
Chris@16: namespace detail
Chris@16: {
Chris@16:   // Guts of is_readable_iterator.  Value is the iterator's value_type
Chris@16:   // and the result is computed in the nested rebind template.
Chris@16:   template <class Value>
Chris@16:   struct is_readable_iterator_impl
Chris@16:   {
Chris@16:       static char tester(Value&, int);
Chris@16:       static char (& tester(any_conversion_eater, ...) )[2];
Chris@101: 
Chris@16:       template <class It>
Chris@16:       struct rebind
Chris@16:       {
Chris@16:           static It& x;
Chris@101: 
Chris@16:           BOOST_STATIC_CONSTANT(
Chris@16:               bool
Chris@16:             , value = (
Chris@16:                 sizeof(
Chris@16:                     is_readable_iterator_impl<Value>::tester(*x, 1)
Chris@16:                 ) == 1
Chris@16:             )
Chris@16:           );
Chris@16:       };
Chris@16:   };
Chris@16: 
Chris@16: #undef BOOST_READABLE_PRESERVER
Chris@101: 
Chris@16:   //
Chris@16:   // void specializations to handle std input and output iterators
Chris@16:   //
Chris@16:   template <>
Chris@16:   struct is_readable_iterator_impl<void>
Chris@16:   {
Chris@16:       template <class It>
Chris@16:       struct rebind : boost::mpl::false_
Chris@16:       {};
Chris@16:   };
Chris@16: 
Chris@16: #ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
Chris@16:   template <>
Chris@16:   struct is_readable_iterator_impl<const void>
Chris@16:   {
Chris@16:       template <class It>
Chris@16:       struct rebind : boost::mpl::false_
Chris@16:       {};
Chris@16:   };
Chris@16: 
Chris@16:   template <>
Chris@16:   struct is_readable_iterator_impl<volatile void>
Chris@16:   {
Chris@16:       template <class It>
Chris@16:       struct rebind : boost::mpl::false_
Chris@16:       {};
Chris@16:   };
Chris@16: 
Chris@16:   template <>
Chris@16:   struct is_readable_iterator_impl<const volatile void>
Chris@16:   {
Chris@16:       template <class It>
Chris@16:       struct rebind : boost::mpl::false_
Chris@16:       {};
Chris@16:   };
Chris@16: #endif
Chris@16: 
Chris@16:   //
Chris@16:   // This level of dispatching is required for Borland.  We might save
Chris@16:   // an instantiation by removing it for others.
Chris@16:   //
Chris@16:   template <class It>
Chris@16:   struct is_readable_iterator_impl2
Chris@16:     : is_readable_iterator_impl<
Chris@16:           BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<It>::value_type const
Chris@16:       >::template rebind<It>
Chris@16:   {};
Chris@16: } // namespace detail
Chris@16: 
Chris@16: // Define the trait with full mpl lambda capability and various broken
Chris@16: // compiler workarounds
Chris@16: BOOST_TT_AUX_BOOL_TRAIT_DEF1(
Chris@101:     is_readable_iterator,T,::boost::iterators::detail::is_readable_iterator_impl2<T>::value)
Chris@101: 
Chris@101: } // namespace iterators
Chris@101: 
Chris@101: using iterators::is_readable_iterator;
Chris@101: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/iterator/detail/config_undef.hpp>
Chris@16: 
Chris@16: #endif // IS_READABLE_ITERATOR_DWA2003112_HPP