00001 /*************************************************************************** 00002 tag: FMTC do nov 2 13:05:59 CET 2006 NA.hpp 00003 00004 NA.hpp - description 00005 ------------------- 00006 begin : do november 02 2006 00007 copyright : (C) 2006 FMTC 00008 email : peter.soetens@fmtc.be 00009 00010 *************************************************************************** 00011 * This library is free software; you can redistribute it and/or * 00012 * modify it under the terms of the GNU General Public * 00013 * License as published by the Free Software Foundation; * 00014 * version 2 of the License. * 00015 * * 00016 * As a special exception, you may use this file as part of a free * 00017 * software library without restriction. Specifically, if other files * 00018 * instantiate templates or use macros or inline functions from this * 00019 * file, or you compile this file and link it with other files to * 00020 * produce an executable, this file does not by itself cause the * 00021 * resulting executable to be covered by the GNU General Public * 00022 * License. This exception does not however invalidate any other * 00023 * reasons why the executable file might be covered by the GNU General * 00024 * Public License. * 00025 * * 00026 * This library is distributed in the hope that it will be useful, * 00027 * but WITHOUT ANY WARRANTY; without even the implied warranty of * 00028 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * 00029 * Lesser General Public License for more details. * 00030 * * 00031 * You should have received a copy of the GNU General Public * 00032 * License along with this library; if not, write to the Free Software * 00033 * Foundation, Inc., 59 Temple Place, * 00034 * Suite 330, Boston, MA 02111-1307 USA * 00035 * * 00036 ***************************************************************************/ 00037 00038 00039 #ifndef ORO_NA_HPP 00040 #define ORO_NA_HPP 00041 00042 #include <boost/type_traits.hpp> 00043 00044 namespace RTT 00045 { 00046 namespace internal 00047 { 00052 template<class T> 00053 struct NA 00054 { 00055 public: 00056 typedef typename boost::remove_const<typename boost::remove_reference<T>::type>::type value_type; 00057 static T na() { return Gna; } 00058 private: 00059 static value_type Gna; 00060 }; 00061 00065 template<> 00066 struct NA<void> 00067 { 00068 typedef void value_type; 00069 static void na() {}; 00070 }; 00071 00072 template<class T> 00073 typename NA<T>::value_type NA<T>::Gna; 00074 } 00075 } 00076 #endif