archive_num.hpp

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/*********************************************************************/
// dar - disk archive - a backup/restoration program
// Copyright (C) 2002-2024 Denis Corbin
//
// 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 for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
// to contact the author, see the AUTHOR file
/*********************************************************************/
 
 
 
#ifndef ARCHIVE_NUM_HPP
#define ARCHIVE_NUM_HPP
 
#include "../my_config.h"
 
#include "integers.hpp"
#include "erreurs.hpp"
 
namespace libdar
{
 
 
    // no need to dig into this class from the API
    class generic_file;
 
 
    class archive_num
    {
    public:
    archive_num(U_16 arg = 0) { set(arg); };
    archive_num(const archive_num & ref) = default;
    archive_num(archive_num && ref) noexcept = default;
    archive_num & operator = (const archive_num & ref) = default;
    archive_num & operator = (archive_num && ref) = default;
    ~archive_num() = default;
 
 
    operator U_16() const { return val; };
    U_16 operator = (U_16 arg) { set(arg); return arg; };
    archive_num & operator++() { set(val+1); return *this; };
 
        // no need of order operator (<, <=, >, >=, ==, !=)
        // thanks to the implicit conversion to U_16 defined
        // above
 
    void read_from_file(generic_file &f);
    void write_to_file(generic_file &f) const;
 
    private:
    static constexpr U_I val_size = sizeof(U_16);
    static constexpr U_I MAX = 65534;
 
    U_16 val;
 
    inline void set(U_16 arg)
    {
        if(arg >= MAX)
        throw SRC_BUG;
        val = arg;
    }
    };
 
 
} // end of namespace
 
#endif