-// Copyright David Abrahams 2003. Use, modification and distribution is\r
-// subject to the Boost Software License, Version 1.0. (See accompanying\r
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)\r
-#ifndef IS_LVALUE_ITERATOR_DWA2003112_HPP\r
-# define IS_LVALUE_ITERATOR_DWA2003112_HPP\r
-\r
-#include <boost/iterator.hpp>\r
-\r
-#include <boost/detail/workaround.hpp>\r
-#include <boost/detail/iterator.hpp>\r
-\r
-#include <boost/iterator/detail/any_conversion_eater.hpp>\r
-\r
-// should be the last #includes\r
-#include <boost/type_traits/detail/bool_trait_def.hpp>\r
-#include <boost/iterator/detail/config_def.hpp>\r
-\r
-#ifndef BOOST_NO_IS_CONVERTIBLE\r
-\r
-namespace boost {\r
- \r
-namespace detail\r
-{\r
-#ifndef BOOST_NO_LVALUE_RETURN_DETECTION\r
- // Calling lvalue_preserver( <expression>, 0 ) returns a reference\r
- // to the expression's result if <expression> is an lvalue, or\r
- // not_an_lvalue() otherwise.\r
- struct not_an_lvalue {};\r
- \r
- template <class T>\r
- T& lvalue_preserver(T&, int);\r
- \r
- template <class U>\r
- not_an_lvalue lvalue_preserver(U const&, ...);\r
- \r
-# define BOOST_LVALUE_PRESERVER(expr) detail::lvalue_preserver(expr,0)\r
- \r
-#else\r
- \r
-# define BOOST_LVALUE_PRESERVER(expr) expr\r
- \r
-#endif \r
-\r
- // Guts of is_lvalue_iterator. Value is the iterator's value_type\r
- // and the result is computed in the nested rebind template.\r
- template <class Value>\r
- struct is_lvalue_iterator_impl\r
- {\r
- // Eat implicit conversions so we don't report true for things\r
- // convertible to Value const&\r
- struct conversion_eater\r
- {\r
- conversion_eater(Value&);\r
- };\r
-\r
- static char tester(conversion_eater, int);\r
- static char (& tester(any_conversion_eater, ...) )[2];\r
- \r
- template <class It>\r
- struct rebind\r
- {\r
- static It& x;\r
- \r
- BOOST_STATIC_CONSTANT(\r
- bool\r
- , value = (\r
- sizeof(\r
- is_lvalue_iterator_impl<Value>::tester(\r
- BOOST_LVALUE_PRESERVER(*x), 0\r
- )\r
- ) == 1\r
- )\r
- );\r
- };\r
- };\r
-\r
-#undef BOOST_LVALUE_PRESERVER\r
- \r
- //\r
- // void specializations to handle std input and output iterators\r
- //\r
- template <>\r
- struct is_lvalue_iterator_impl<void>\r
- {\r
- template <class It>\r
- struct rebind : boost::mpl::false_\r
- {};\r
- };\r
-\r
-#ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS\r
- template <>\r
- struct is_lvalue_iterator_impl<const void>\r
- {\r
- template <class It>\r
- struct rebind : boost::mpl::false_\r
- {};\r
- };\r
-\r
- template <>\r
- struct is_lvalue_iterator_impl<volatile void>\r
- {\r
- template <class It>\r
- struct rebind : boost::mpl::false_\r
- {};\r
- };\r
-\r
- template <>\r
- struct is_lvalue_iterator_impl<const volatile void>\r
- {\r
- template <class It>\r
- struct rebind : boost::mpl::false_\r
- {};\r
- };\r
-#endif\r
-\r
- //\r
- // This level of dispatching is required for Borland. We might save\r
- // an instantiation by removing it for others.\r
- //\r
- template <class It>\r
- struct is_readable_lvalue_iterator_impl\r
- : is_lvalue_iterator_impl<\r
- BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<It>::value_type const\r
- >::template rebind<It>\r
- {};\r
-\r
- template <class It>\r
- struct is_non_const_lvalue_iterator_impl\r
- : is_lvalue_iterator_impl<\r
- BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<It>::value_type\r
- >::template rebind<It>\r
- {};\r
-} // namespace detail\r
-\r
-// Define the trait with full mpl lambda capability and various broken\r
-// compiler workarounds\r
-BOOST_TT_AUX_BOOL_TRAIT_DEF1(\r
- is_lvalue_iterator,T,::boost::detail::is_readable_lvalue_iterator_impl<T>::value)\r
- \r
-BOOST_TT_AUX_BOOL_TRAIT_DEF1(\r
- is_non_const_lvalue_iterator,T,::boost::detail::is_non_const_lvalue_iterator_impl<T>::value)\r
- \r
-} // namespace boost\r
-\r
-#endif\r
-\r
-#include <boost/iterator/detail/config_undef.hpp>\r
-#include <boost/type_traits/detail/bool_trait_undef.hpp>\r
-\r
-#endif // IS_LVALUE_ITERATOR_DWA2003112_HPP\r
+// 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_LVALUE_ITERATOR_DWA2003112_HPP
+# define IS_LVALUE_ITERATOR_DWA2003112_HPP
+
+#include <boost/iterator.hpp>
+
+#include <boost/detail/workaround.hpp>
+#include <boost/detail/iterator.hpp>
+
+#include <boost/iterator/detail/any_conversion_eater.hpp>
+
+// should be the last #includes
+#include <boost/type_traits/detail/bool_trait_def.hpp>
+#include <boost/iterator/detail/config_def.hpp>
+
+#ifndef BOOST_NO_IS_CONVERTIBLE
+
+namespace boost {
+
+namespace detail
+{
+#ifndef BOOST_NO_LVALUE_RETURN_DETECTION
+ // Calling lvalue_preserver( <expression>, 0 ) returns a reference
+ // to the expression's result if <expression> is an lvalue, or
+ // not_an_lvalue() otherwise.
+ struct not_an_lvalue {};
+
+ template <class T>
+ T& lvalue_preserver(T&, int);
+
+ template <class U>
+ not_an_lvalue lvalue_preserver(U const&, ...);
+
+# define BOOST_LVALUE_PRESERVER(expr) detail::lvalue_preserver(expr,0)
+
+#else
+
+# define BOOST_LVALUE_PRESERVER(expr) expr
+
+#endif
+
+ // Guts of is_lvalue_iterator. Value is the iterator's value_type
+ // and the result is computed in the nested rebind template.
+ template <class Value>
+ struct is_lvalue_iterator_impl
+ {
+ // Eat implicit conversions so we don't report true for things
+ // convertible to Value const&
+ struct conversion_eater
+ {
+ conversion_eater(Value&);
+ };
+
+ static char tester(conversion_eater, int);
+ static char (& tester(any_conversion_eater, ...) )[2];
+
+ template <class It>
+ struct rebind
+ {
+ static It& x;
+
+ BOOST_STATIC_CONSTANT(
+ bool
+ , value = (
+ sizeof(
+ is_lvalue_iterator_impl<Value>::tester(
+ BOOST_LVALUE_PRESERVER(*x), 0
+ )
+ ) == 1
+ )
+ );
+ };
+ };
+
+#undef BOOST_LVALUE_PRESERVER
+
+ //
+ // void specializations to handle std input and output iterators
+ //
+ template <>
+ struct is_lvalue_iterator_impl<void>
+ {
+ template <class It>
+ struct rebind : boost::mpl::false_
+ {};
+ };
+
+#ifndef BOOST_NO_CV_VOID_SPECIALIZATIONS
+ template <>
+ struct is_lvalue_iterator_impl<const void>
+ {
+ template <class It>
+ struct rebind : boost::mpl::false_
+ {};
+ };
+
+ template <>
+ struct is_lvalue_iterator_impl<volatile void>
+ {
+ template <class It>
+ struct rebind : boost::mpl::false_
+ {};
+ };
+
+ template <>
+ struct is_lvalue_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_lvalue_iterator_impl
+ : is_lvalue_iterator_impl<
+ BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<It>::value_type const
+ >::template rebind<It>
+ {};
+
+ template <class It>
+ struct is_non_const_lvalue_iterator_impl
+ : is_lvalue_iterator_impl<
+ BOOST_DEDUCED_TYPENAME boost::detail::iterator_traits<It>::value_type
+ >::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_lvalue_iterator,T,::boost::detail::is_readable_lvalue_iterator_impl<T>::value)
+
+BOOST_TT_AUX_BOOL_TRAIT_DEF1(
+ is_non_const_lvalue_iterator,T,::boost::detail::is_non_const_lvalue_iterator_impl<T>::value)
+
+} // namespace boost
+
+#endif
+
+#include <boost/iterator/detail/config_undef.hpp>
+#include <boost/type_traits/detail/bool_trait_undef.hpp>
+
+#endif // IS_LVALUE_ITERATOR_DWA2003112_HPP
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