2 #ifndef BOOST_MPL_VOID_HPP_INCLUDED
3 #define BOOST_MPL_VOID_HPP_INCLUDED
5 // Copyright Aleksey Gurtovoy 2001-2004
7 // Distributed under the Boost Software License, Version 1.0.
8 // (See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt)
11 // See http://www.boost.org/libs/mpl for documentation.
13 // $Id: void.hpp 49267 2008-10-11 06:19:02Z agurtovoy $
14 // $Date: 2008-10-11 02:19:02 -0400 (Sat, 11 Oct 2008) $
17 #include <boost/mpl/void_fwd.hpp>
18 #include <boost/mpl/bool.hpp>
19 #include <boost/mpl/aux_/na_spec.hpp>
20 #include <boost/mpl/aux_/config/msvc.hpp>
21 #include <boost/mpl/aux_/config/workaround.hpp>
23 BOOST_MPL_AUX_ADL_BARRIER_NAMESPACE_OPEN
25 // [JDG Feb-4-2003] made void_ a complete type to allow it to be
26 // instantiated so that it can be passed in as an object that can be
27 // used to select an overloaded function. Possible use includes signaling
28 // a zero arity functor evaluation call.
29 struct void_
{ typedef void_ type
; };
31 BOOST_MPL_AUX_ADL_BARRIER_NAMESPACE_CLOSE
33 namespace boost
{ namespace mpl
{
35 template< typename T
>
39 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
45 struct is_void_
<void_
>
48 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
53 template< typename T
>
57 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
63 struct is_not_void_
<void_
>
66 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
71 BOOST_MPL_AUX_NA_SPEC(1, is_void_
)
72 BOOST_MPL_AUX_NA_SPEC(1, is_not_void_
)
76 #endif // BOOST_MPL_VOID_HPP_INCLUDED