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