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- //-----------------------------------------------------------------------------
- // boost variant/detail/over_sequence.hpp header file
- // See http://www.boost.org for updates, documentation, and revision history.
- //-----------------------------------------------------------------------------
- //
- // Copyright (c) 2003
- // Eric Friedman
- //
- // Portions Copyright (C) 2002 David Abrahams
- //
- // Distributed under 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 BOOST_VARIANT_DETAIL_OVER_SEQUENCE_HPP
- #define BOOST_VARIANT_DETAIL_OVER_SEQUENCE_HPP
- #include "boost/mpl/aux_/config/ctps.hpp"
- #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
- # include "boost/mpl/eval_if.hpp"
- # include "boost/mpl/bool.hpp"
- # include "boost/mpl/identity.hpp"
- # include "boost/type.hpp"
- #endif
- namespace boost {
- namespace detail { namespace variant {
- ///////////////////////////////////////////////////////////////////////////////
- // (detail) class over_sequence
- //
- // Wrapper used to indicate bounded types for variant are from type sequence.
- //
- template <typename Types>
- struct over_sequence
- {
- typedef Types type;
- };
- ///////////////////////////////////////////////////////////////////////////////
- // (detail) metafunction is_over_sequence (modeled on code by David Abrahams)
- //
- // Indicates whether the specified type is of form over_sequence<...> or not.
- //
- #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
- template <typename T>
- struct is_over_sequence
- : mpl::false_
- {
- };
- template <typename Types>
- struct is_over_sequence< over_sequence<Types> >
- : mpl::true_
- {
- };
- #else // defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
- typedef char (&yes_over_sequence_t)[1];
- typedef char (&no_over_sequence_t)[2];
- no_over_sequence_t is_over_sequence_test(...);
- template<typename T>
- yes_over_sequence_t is_over_sequence_test(
- type< ::boost::detail::variant::over_sequence<T> >
- );
- template<typename T>
- struct is_over_sequence_impl
- {
- BOOST_STATIC_CONSTANT(bool, value = (
- sizeof(is_over_sequence_test(type<T>()))
- == sizeof(yes_over_sequence_t)
- ));
- };
- template <typename T>
- struct is_over_sequence
- : mpl::bool_<
- ::boost::detail::variant::is_over_sequence_impl<T>::value
- >
- {
- };
- #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION workaround
- }} // namespace detail::variant
- } // namespace boost
- #endif // BOOST_VARIANT_DETAIL_OVER_SEQUENCE_HPP
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