Line data    Source code

       1             : // The libMesh Finite Element Library.
       2             : // Copyright (C) 2002-2025 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner
       3             : 
       4             : // This library is free software; you can redistribute it and/or
       5             : // modify it under the terms of the GNU Lesser General Public
       6             : // License as published by the Free Software Foundation; either
       7             : // version 2.1 of the License, or (at your option) any later version.
       8             : 
       9             : // This library is distributed in the hope that it will be useful,
      10             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12             : // Lesser General Public License for more details.
      13             : 
      14             : // You should have received a copy of the GNU Lesser General Public
      15             : // License along with this library; if not, write to the Free Software
      16             : // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
      17             : 
      18             : #ifndef LIBMESH_ZERO_FUNCTION_H
      19             : #define LIBMESH_ZERO_FUNCTION_H
      20             : 
      21             : // Local includes
      22             : #include "libmesh/const_function.h"
      23             : 
      24             : // C++ Includes
      25             : #include <memory>
      26             : 
      27             : namespace libMesh
      28             : {
      29             : 
      30             : /**
      31             :  * ConstFunction that simply returns 0.
      32             :  *
      33             :  * \author Roy Stogner
      34             :  * \date 2012
      35             :  * \brief ConstFunction that simply returns 0.
      36             :  */
      37             : template <typename Output=Number>
      38             : class ZeroFunction : public ConstFunction<Output>
      39             : {
      40             : public:
      41        1566 :   ZeroFunction () : ConstFunction<Output>(0) {}
      42             : 
      43             :   /**
      44             :    * The 5 special functions can be defaulted for this class.
      45             :    */
      46             :   ZeroFunction (ZeroFunction &&) = default;
      47             :   ZeroFunction (const ZeroFunction &) = default;
      48             :   ZeroFunction & operator= (const ZeroFunction &) = default;
      49             :   ZeroFunction & operator= (ZeroFunction &&) = default;
      50        2658 :   virtual ~ZeroFunction () = default;
      51             : 
      52        1136 :   virtual std::unique_ptr<FunctionBase<Output>> clone() const override
      53             :   {
      54        1136 :     return std::make_unique<ZeroFunction<Output>>();
      55             :   }
      56             : };
      57             : 
      58             : } // namespace libMesh
      59             : 
      60             : #endif // LIBMESH_ZERO_FUNCTION_H