/Src/Dependencies/Boost/boost/variant/detail/make_variant_list.hpp

 1//-----------------------------------------------------------------------------
 2// boost variant/detail/make_variant_list.hpp header file
 3// See http://www.boost.org for updates, documentation, and revision history.
 4//-----------------------------------------------------------------------------
 5//
 6// Copyright (c) 2002-2003
 7// Eric Friedman, Itay Maman
 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_MAKE_VARIANT_LIST_HPP
14#define BOOST_VARIANT_DETAIL_MAKE_VARIANT_LIST_HPP
15
16#include "boost/variant/variant_fwd.hpp"
17
18#include "boost/mpl/list.hpp"
19#include "boost/preprocessor/cat.hpp"
20#include "boost/preprocessor/enum.hpp"
21
22namespace boost {
23namespace detail { namespace variant {
24
25///////////////////////////////////////////////////////////////////////////////
26// (detail) metafunction make_variant_list
27//
28// Provides a MPL-compatible sequence with the specified non-void types
29// as arguments.
30//
31// Rationale: see class template convert_void (variant_fwd.hpp) and using-
32// declaration workaround (below).
33//
34template < BOOST_VARIANT_ENUM_PARAMS(typename T) >
35struct make_variant_list
36{
37public: // metafunction result
38
39    // [Define a macro to convert any void(NN) tags to mpl::void...]
40#   define BOOST_VARIANT_AUX_CONVERT_VOID(z, N,_)  \
41        typename convert_void< BOOST_PP_CAT(T,N) >::type
42
43    // [...so that the specified types can be passed to mpl::list...]
44    typedef typename mpl::list< 
45          BOOST_PP_ENUM(
46              BOOST_VARIANT_LIMIT_TYPES
47            , BOOST_VARIANT_AUX_CONVERT_VOID
48            , _
49            )
50        >::type type;
51
52    // [...and, finally, the conversion macro can be undefined:]
53#   undef BOOST_VARIANT_AUX_CONVERT_VOID
54
55};
56
57}} // namespace detail::variant
58} // namespace boost
59
60#endif // BOOST_VARIANT_DETAIL_MAKE_VARIANT_LIST_HPP