ios_state.h

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///
/// \file       ios_state.h
///             RAII class to save and restore iostream state
///

/*
    Copyright (C) 2011-2012, Net Direct Inc. (http://www.netdirect.ca/)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License in the COPYING file at the
    root directory of this project for more details.
*/

#ifndef __BARRY_IOS_STATE_H__
#define __BARRY_IOS_STATE_H__

#include <ios>
#include <ostream>

namespace Barry {

//
// ios_format_state
//
/// This class saves the following stream settings:
///     - flags
///     - precision
///     - width
///     - fill character
///
/// and restores them in the destructor.
///
class ios_format_state
{
public:
        typedef std::ios                stream_type;

private:
        stream_type                     &m_stream;
        std::ios_base::fmtflags         m_flags;
        std::streamsize                 m_precision;
        std::streamsize                 m_width;
        stream_type::char_type          m_fill;

public:
        explicit ios_format_state(stream_type &stream)
                : m_stream(stream)
                , m_flags(stream.flags())
                , m_precision(stream.precision())
                , m_width(stream.width())
                , m_fill(stream.fill())
        {
        }

        ~ios_format_state()
        {
                restore();
        }

        void restore()
        {
                m_stream.flags(m_flags);
                m_stream.precision(m_precision);
                m_stream.width(m_width);
                m_stream.fill(m_fill);
        }
};

}

#endif