Enum.h

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/*
 * Copyright (c) 2010 Novell, Inc.
 *
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as published
 * by the Free Software Foundation.
 *
 * 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, contact Novell, Inc.
 *
 * To contact Novell about this file by physical or electronic mail, you may
 * find current contact information at www.novell.com.
 */


#ifndef ENUM_H
#define ENUM_H


#include <assert.h>
#include <string>
#include <vector>
#include <algorithm>

#include "storage/StorageInterface.h"
#include "storage/AppUtil.h"


namespace storage
{
    using std::string;
    using std::vector;


    template <typename EnumType> struct EnumInfo {};

    template <> struct EnumInfo<FsType> { static const vector<string> names; };
    template <> struct EnumInfo<PartitionType> { static const vector<string> names; };
    template <> struct EnumInfo<MountByType> { static const vector<string> names; };
    template <> struct EnumInfo<EncryptType> { static const vector<string> names; };
    template <> struct EnumInfo<MdType> { static const vector<string> names; };
    template <> struct EnumInfo<MdParity> { static const vector<string> names; };
    template <> struct EnumInfo<MdArrayState> { static const vector<string> names; };
    template <> struct EnumInfo<UsedByType> { static const vector<string> names; };
    template <> struct EnumInfo<CType> { static const vector<string> names; };
    template <> struct EnumInfo<Transport> { static const vector<string> names; };
    template <> struct EnumInfo<ImsmDriver> { static const vector<string> names; };
    template <> struct EnumInfo<MultipathAutostart> { static const vector<string> names; };
    template <> struct EnumInfo<PartAlign> { static const vector<string> names; };


    template <typename EnumType>
    const string& toString(EnumType value)
    {
        static_assert(std::is_enum<EnumType>::value, "not enum");

        const vector<string>& names = EnumInfo<EnumType>::names;

        // Comparisons must not be done with type of enum since the enum may
        // define comparison operators.
        assert((size_t)(value) < names.size());

        return names[value];
    }


    template <typename EnumType>
    bool toValue(const string& str, EnumType& value, bool log_error = true)
    {
        static_assert(std::is_enum<EnumType>::value, "not enum");

        const vector<string>& names = EnumInfo<EnumType>::names;

        vector<string>::const_iterator it = find(names.begin(), names.end(), str);

        if (it == names.end())
        {
            if (log_error)
                y2err("converting '" << str << "' to enum failed");
            return false;
        }

        value = EnumType(it - names.begin());
        return true;
    }


    template <typename EnumType>
    EnumType toValueWithFallback(const string& str, EnumType fallback, bool log_error = true)
    {
        EnumType value;

        if (toValue(str, value, log_error))
            return value;

        return fallback;
    }

}


#endif

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