williamr@2: williamr@2: #ifndef BOOST_MPL_VOID_HPP_INCLUDED williamr@2: #define BOOST_MPL_VOID_HPP_INCLUDED williamr@2: williamr@2: // Copyright Aleksey Gurtovoy 2001-2004 williamr@2: // williamr@2: // Distributed under the Boost Software License, Version 1.0. williamr@2: // (See accompanying file LICENSE_1_0.txt or copy at williamr@2: // http://www.boost.org/LICENSE_1_0.txt) williamr@2: // williamr@2: // See http://www.boost.org/libs/mpl for documentation. williamr@2: williamr@2: // $Source: /cvsroot/boost/boost/boost/mpl/void.hpp,v $ williamr@2: // $Date: 2004/09/02 15:40:42 $ williamr@2: // $Revision: 1.9 $ williamr@2: williamr@2: #include williamr@2: #include williamr@2: #include williamr@2: #include williamr@2: #include williamr@2: williamr@2: BOOST_MPL_AUX_ADL_BARRIER_NAMESPACE_OPEN williamr@2: williamr@2: // [JDG Feb-4-2003] made void_ a complete type to allow it to be williamr@2: // instantiated so that it can be passed in as an object that can be williamr@2: // used to select an overloaded function. Possible use includes signaling williamr@2: // a zero arity functor evaluation call. williamr@2: struct void_ { typedef void_ type; }; williamr@2: williamr@2: BOOST_MPL_AUX_ADL_BARRIER_NAMESPACE_CLOSE williamr@2: williamr@2: namespace boost { namespace mpl { williamr@2: williamr@2: template< typename T > williamr@2: struct is_void_ williamr@2: : false_ williamr@2: { williamr@2: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) williamr@2: using false_::value; williamr@2: #endif williamr@2: }; williamr@2: williamr@2: template<> williamr@2: struct is_void_ williamr@2: : true_ williamr@2: { williamr@2: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) williamr@2: using true_::value; williamr@2: #endif williamr@2: }; williamr@2: williamr@2: template< typename T > williamr@2: struct is_not_void_ williamr@2: : true_ williamr@2: { williamr@2: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) williamr@2: using true_::value; williamr@2: #endif williamr@2: }; williamr@2: williamr@2: template<> williamr@2: struct is_not_void_ williamr@2: : false_ williamr@2: { williamr@2: #if BOOST_WORKAROUND(BOOST_MSVC, < 1300) williamr@2: using false_::value; williamr@2: #endif williamr@2: }; williamr@2: williamr@2: BOOST_MPL_AUX_NA_SPEC(1, is_void_) williamr@2: BOOST_MPL_AUX_NA_SPEC(1, is_not_void_) williamr@2: williamr@2: }} williamr@2: williamr@2: #endif // BOOST_MPL_VOID_HPP_INCLUDED