/cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/AsgTools/AsgTools/MessagePrinterOverlay.h

#ifndef ASG_TOOLS__MESSAGE_PRINTER_OVERLAY_H
#define ASG_TOOLS__MESSAGE_PRINTER_OVERLAY_H

//        Copyright Iowa State University 2017.
//                  Author: Nils Krumnack
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

// Please feel free to contact me (nils.erik.krumnack@cern.ch) for bug
// reports, feature suggestions, praise and complaints.


namespace asg
{
  class IMessagePrinter;


  class MessagePrinterOverlay final
  {
    //
    // public interface
    //

    MessagePrinterOverlay (MessagePrinterOverlay&) = delete;
    MessagePrinterOverlay operator = (MessagePrinterOverlay&) = delete;


  public:
    MessagePrinterOverlay (IMessagePrinter *val_printer) noexcept;

  public:
    ~MessagePrinterOverlay () noexcept;

  public:
    static IMessagePrinter& current () noexcept;



    //
    // private interface
    //

  private:
    static IMessagePrinter*& getCurrent () noexcept;

  private:
    IMessagePrinter *m_saved = nullptr;

  private:
    IMessagePrinter *m_current = nullptr;
  };
}

#endif

---