const_function.h

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2014 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


#ifndef LIBMESH_CONST_FUNCTION_H
#define LIBMESH_CONST_FUNCTION_H

// Local includes
#include "libmesh/dense_vector.h"
#include "libmesh/function_base.h"
#include "libmesh/point.h"

// C++ includes
#include <string>

namespace libMesh {

template <typename Output=Number>
class ConstFunction : public FunctionBase<Output>
{
public:
  explicit
  ConstFunction (const Output &c) : _c(c) { this->_initialized = true; }

  virtual Output operator() (const Point&,
                             const Real = 0)
  { return _c; }

  virtual void operator() (const Point&,
                           const Real,
                           DenseVector<Output>& output)
  {
    unsigned int size = output.size();
    for (unsigned int i=0; i != size; ++i)
      output(i) = _c;
  }

  virtual UniquePtr<FunctionBase<Output> > clone() const {
    return UniquePtr<FunctionBase<Output> >
      (new ConstFunction<Output>(_c));
  }

private:
  Output _c;
};

} // namespace libMesh

#endif // LIBMESH_CONST_FUNCTION_H