conditional_ostream.h

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// ---------------------------------------------------------------------
//
// Copyright (C) 2004 - 2020 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, 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.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------
 
#ifndef dealii_conditional_ostream_h
#define dealii_conditional_ostream_h
 
#include <deal.II/base/config.h>
 
#include <ostream>
 
DEAL_II_NAMESPACE_OPEN
 
 
class ConditionalOStream
{
public:
  ConditionalOStream(std::ostream &stream, const bool active = true);
 
  void
  set_condition(const bool active);
 
  bool
  is_active() const;
 
  std::ostream &
  get_stream() const;
 
  template <typename T>
  const ConditionalOStream &
  operator<<(const T &t) const;
 
  const ConditionalOStream &
  operator<<(std::ostream &(*p)(std::ostream &)) const;
 
private:
  std::ostream &output_stream;
 
  bool active_flag;
};
 
 
// --------------------------- inline and template functions -----------
 
template <class T>
inline const ConditionalOStream &
ConditionalOStream::operator<<(const T &t) const
{
  if (active_flag == true)
    output_stream << t;
 
  return *this;
}
 
 
inline const ConditionalOStream &
ConditionalOStream::operator<<(std::ostream &(*p)(std::ostream &)) const
{
  if (active_flag == true)
    output_stream << p;
 
  return *this;
}
 
 
inline std::ostream &
ConditionalOStream::get_stream() const
{
  return output_stream;
}
 
 
DEAL_II_NAMESPACE_CLOSE
 
#endif