1 /*=============================================================================
2 Copyright (c) 2001-2014 Joel de Guzman
3 http://spirit.sourceforge.net/
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 =============================================================================*/
8 #if !defined(BOOST_SPIRIT_X3_IS_VARIANT_JAN_10_2012_0823AM)
9 #define BOOST_SPIRIT_X3_IS_VARIANT_JAN_10_2012_0823AM
11 #include <boost/variant.hpp>
12 #include <boost/mpl/has_xxx.hpp>
13 #include <boost/mpl/bool.hpp>
15 namespace boost { namespace spirit { namespace x3 { namespace traits
19 // By declaring a nested struct in your class/struct, you tell
20 // spirit that it is regarded as a variant type. The minimum
21 // required interface for such a variant is that it has constructors
22 // for various types supported by your variant and a typedef 'types'
23 // which is an mpl sequence of the contained types.
25 // This is an intrusive interface. For a non-intrusive interface,
26 // use the is_variant trait.
27 BOOST_MPL_HAS_XXX_TRAIT_DEF(adapted_variant_tag)
30 template <typename T, typename Enable = void>
32 : detail::has_adapted_variant_tag<T>
35 template <BOOST_VARIANT_ENUM_PARAMS(typename T)>
36 struct is_variant<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>>