williamr@2: //----------------------------------------------------------------------------- williamr@2: // boost variant/detail/over_sequence.hpp header file williamr@2: // See http://www.boost.org for updates, documentation, and revision history. williamr@2: //----------------------------------------------------------------------------- williamr@2: // williamr@2: // Copyright (c) 2003 williamr@2: // Eric Friedman williamr@2: // williamr@2: // Portions Copyright (C) 2002 David Abrahams williamr@2: // williamr@2: // Distributed under the Boost Software License, Version 1.0. (See williamr@2: // accompanying file LICENSE_1_0.txt or copy at williamr@2: // http://www.boost.org/LICENSE_1_0.txt) williamr@2: williamr@2: #ifndef BOOST_VARIANT_DETAIL_OVER_SEQUENCE_HPP williamr@2: #define BOOST_VARIANT_DETAIL_OVER_SEQUENCE_HPP williamr@2: williamr@2: #include "boost/mpl/aux_/config/ctps.hpp" williamr@2: #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) williamr@2: # include "boost/mpl/eval_if.hpp" williamr@2: # include "boost/mpl/bool.hpp" williamr@2: # include "boost/mpl/identity.hpp" williamr@2: # include "boost/type.hpp" williamr@2: #endif williamr@2: williamr@2: williamr@2: namespace boost { williamr@2: namespace detail { namespace variant { williamr@2: williamr@2: /////////////////////////////////////////////////////////////////////////////// williamr@2: // (detail) class over_sequence williamr@2: // williamr@2: // Wrapper used to indicate bounded types for variant are from type sequence. williamr@2: // williamr@2: template williamr@2: struct over_sequence williamr@2: { williamr@2: typedef Types type; williamr@2: }; williamr@2: williamr@2: /////////////////////////////////////////////////////////////////////////////// williamr@2: // (detail) metafunction is_over_sequence (modeled on code by David Abrahams) williamr@2: // williamr@2: // Indicates whether the specified type is of form over_sequence<...> or not. williamr@2: // williamr@2: williamr@2: #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) williamr@2: williamr@2: template williamr@2: struct is_over_sequence williamr@2: : mpl::false_ williamr@2: { williamr@2: }; williamr@2: williamr@2: template williamr@2: struct is_over_sequence< over_sequence > williamr@2: : mpl::true_ williamr@2: { williamr@2: }; williamr@2: williamr@2: #else // defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) williamr@2: williamr@2: typedef char (&yes_over_sequence_t)[1]; williamr@2: typedef char (&no_over_sequence_t)[2]; williamr@2: williamr@2: no_over_sequence_t is_over_sequence_test(...); williamr@2: williamr@2: template williamr@2: yes_over_sequence_t is_over_sequence_test( williamr@2: type< ::boost::detail::variant::over_sequence > williamr@2: ); williamr@2: williamr@2: template williamr@2: struct is_over_sequence_impl williamr@2: { williamr@2: BOOST_STATIC_CONSTANT(bool, value = ( williamr@2: sizeof(is_over_sequence_test(type())) williamr@2: == sizeof(yes_over_sequence_t) williamr@2: )); williamr@2: }; williamr@2: williamr@2: template williamr@2: struct is_over_sequence williamr@2: : mpl::bool_< williamr@2: ::boost::detail::variant::is_over_sequence_impl::value williamr@2: > williamr@2: { williamr@2: }; williamr@2: williamr@2: #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION workaround williamr@2: williamr@2: }} // namespace detail::variant williamr@2: } // namespace boost williamr@2: williamr@2: #endif // BOOST_VARIANT_DETAIL_OVER_SEQUENCE_HPP