boost_util.h Source File

00001 //  ======================================================================== //
00002 //                                                                           //
00003 //    File      : boost_util.h                                               //
00004 //    Purpose   : Code from boost library (see http://www.boost.org/)        //
00005 //    Time-stamp: <Wed Nov/13/2002 08:30 MET Coder@ReallySoft.de>            //
00006 //                                                                           //
00007 //    (C) May 2002 by Ralf Westram                                           //
00008 //                                                                           //
00009 //    Permission to use, copy, modify, distribute and sell this software     //
00010 //    and its documentation for any purpose is hereby granted without fee,   //
00011 //    provided that the above copyright notice appear in all copies and      //
00012 //    that both that copyright notice and this permission notice appear      //
00013 //    in supporting documentation.                                           //
00014 //                                                                           //
00015 //    Ralf Westram makes no representations about the suitability of this    //
00016 //    software for any purpose.  It is provided "as is" without express or   //
00017 //    implied warranty.                                                      //
00018 //                                                                           //
00019 //  ======================================================================== //
00020 
00021 #ifndef BOOST_UTIL_H
00022 #define BOOST_UTIL_H
00023 
00024 #ifndef CSTDLIB
00025 #include <cstdlib>
00026 #endif
00027 
00028 
00029 namespace rs {
00030 
00035     namespace rs_boost {
00036 
00052         template <class T>
00053         T next(T x) { return ++x; }
00054 
00056         template <class T>
00057         T prior(T x) { return --x; }
00058 
00059 
00068         class noncopyable
00069         {
00070         protected:
00071             noncopyable(){}
00072             ~noncopyable(){}
00073         private:  // emphasize the following members are private
00074             noncopyable( const noncopyable& );
00075             const noncopyable& operator=( const noncopyable& );
00076         };
00077 
00083         template <class X>
00084         class counted {
00085             static size_t instances;
00086             static size_t max_instances;
00087         public:
00088             counted() {
00089                 ++instances;
00090                 if (instances>max_instances) max_instances = instances;
00091             }
00092             ~counted() { --instances; }
00093 
00094             size_t get_instances() const { return instances; }
00095             size_t get_max_instances() const { return max_instances; }
00096         };
00097 
00098         template <class X> size_t counted<X>::instances = 0;
00099         template <class X> size_t counted<X>::max_instances = 0;
00100 
00101         void second_instance_error();
00102 
00111         template <class X>
00112         class singleton : counted<X> {
00113         public:
00115             singleton() : counted<X>()  {
00116                 if (get_instances()>1) second_instance_error();
00117             }
00118             ~singleton() {}
00119         };
00120     };
00121 
00122 }; // end of namespace rs
00123 
00124 #else
00125 #error boost_util.h included twice
00126 #endif // BOOST_UTIL_H
00127