conditional_ostream.h

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// ------------------------------------------------------------------------
//
// SPDX-License-Identifier: LGPL-2.1-or-later
// Copyright (C) 2004 - 2023 by the deal.II authors
//
// This file is part of the deal.II library.
//
// Part of the source code is dual licensed under Apache-2.0 WITH
// LLVM-exception OR LGPL-2.1-or-later. Detailed license information
// governing the source code and code contributions can be found in
// LICENSE.md and CONTRIBUTING.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:
  explicit 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