Line data    Source code

       1              : /*
       2              :  * Copyright (c) 2011-2015:  G-CSC, Goethe University Frankfurt
       3              :  * Author: Andreas Vogel
       4              :  * 
       5              :  * This file is part of UG4.
       6              :  * 
       7              :  * UG4 is free software: you can redistribute it and/or modify it under the
       8              :  * terms of the GNU Lesser General Public License version 3 (as published by the
       9              :  * Free Software Foundation) with the following additional attribution
      10              :  * requirements (according to LGPL/GPL v3 §7):
      11              :  * 
      12              :  * (1) The following notice must be displayed in the Appropriate Legal Notices
      13              :  * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
      14              :  * 
      15              :  * (2) The following notice must be displayed at a prominent place in the
      16              :  * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
      17              :  * 
      18              :  * (3) The following bibliography is recommended for citation and must be
      19              :  * preserved in all covered files:
      20              :  * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
      21              :  *   parallel geometric multigrid solver on hierarchically distributed grids.
      22              :  *   Computing and visualization in science 16, 4 (2013), 151-164"
      23              :  * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
      24              :  *   flexible software system for simulating pde based models on high performance
      25              :  *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
      26              :  * 
      27              :  * This program is distributed in the hope that it will be useful,
      28              :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      29              :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
      30              :  * GNU Lesser General Public License for more details.
      31              :  */
      32              : 
      33              : #ifndef __H__COMMON__UTIL__PROVIDER__
      34              : #define __H__COMMON__UTIL__PROVIDER__
      35              : 
      36              : namespace ug{
      37              : 
      38              : /// \addtogroup ugbase_common_util
      39              : /// \{
      40              : 
      41              : /// Provider, holding a single instance of an object
      42              : /**
      43              :  * This class is used to wrap an object into a singleton-like provider, such
      44              :  * that construction computations is avoided, if the object is used several times.
      45              :  */
      46              : template <typename TClass>
      47              : class Provider
      48              : {
      49              :         public:
      50              :                 ///     type of provided object
      51              :                 typedef TClass Type;
      52              : 
      53              :                 ///     returns a singleton based on the identifier
      54           38 :                 static inline TClass& get(){
      55           38 :                         static TClass inst;
      56           38 :                         return inst;
      57              :                 }
      58              : };
      59              : 
      60              : // end group ugbase_common_util
      61              : /// \}
      62              : 
      63              : } // end namespace ug
      64              : 
      65              : #endif /* __H__COMMON__UTIL__PROVIDER__ */