1 //-----------------------------------------------------------------------------
2 // boost variant/detail/substitute_fwd.hpp header file
3 // See http://www.boost.org for updates, documentation, and revision history.
4 //-----------------------------------------------------------------------------
5 //
6 // Copyright (c) 2003
7 // Eric Friedman
8 //
9 // Distributed under the Boost Software License, Version 1.0. (See
10 // accompanying file LICENSE_1_0.txt or copy at
11 // http://www.boost.org/LICENSE_1_0.txt)
12 
13 #ifndef BOOST_VARIANT_DETAIL_SUBSTITUTE_FWD_HPP
14 #define BOOST_VARIANT_DETAIL_SUBSTITUTE_FWD_HPP
15 
16 #include <boost/mpl/aux_/lambda_arity_param.hpp>
17 #include <boost/mpl/aux_/template_arity.hpp>
18 #include <boost/mpl/int_fwd.hpp>
19 
20 
21 ///////////////////////////////////////////////////////////////////////////////
22 // BOOST_VARIANT_DETAIL_NO_SUBSTITUTE
23 //
24 // Defined if 'substitute' is not implementable on the current compiler.
25 //
26 
27 #include <boost/mpl/aux_/config/ctps.hpp>
28 #include <boost/mpl/aux_/config/ttp.hpp>
29 
30 #if defined(BOOST_NO_TEMPLATE_TEMPLATE_PARAMETERS) \
31  && !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
32 #   define BOOST_VARIANT_DETAIL_NO_SUBSTITUTE
33 #endif
34 
35 namespace boost {
36 namespace detail { namespace variant {
37 
38 #if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
39 
40 ///////////////////////////////////////////////////////////////////////////////
41 // metafunction substitute
42 //
43 // Substitutes one type for another in the given type expression.
44 //
45 template <
46       typename T, typename Dest, typename Source
47       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(
48           typename Arity = mpl::int_< mpl::aux::template_arity<T>::value >
49         )
50     >
51 struct substitute;
52 
53 #endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
54 
55 }} // namespace detail::variant
56 } // namespace boost
57 
58 #endif // BOOST_VARIANT_DETAIL_SUBSTITUTE_FWD_HPP
59