one/include/EnumString.h

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/* Copyright 2002-2019, OpenNebula Project, OpenNebula Systems                */
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/* Licensed under the Apache License, Version 2.0 (the "License"); you may    */
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/* http://www.apache.org/licenses/LICENSE-2.0                                 */
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/* -------------------------------------------------------------------------- */

#ifndef ENUM_STRING_H
#define ENUM_STRING_H

#include <map>
#include <algorithm>
#include <assert.h>
#include <typeinfo>
#include <sstream>

/**
 * Converts string to enum and back
 */
template <typename T>
class EString
{
public:
    /**
     * Constructor
     *  @param _em map with string associations
     *  @param check_sanity check that all enums have a string representation
     *          Works only for continuous enums starting with zero
     *          Last enum must be ENUM_MAX
     */
    EString(const std::map<std::string, T>&& _em, bool check_sanity = true)
        : enum_map(_em)
    {
        if (check_sanity && (int)T::ENUM_MAX != enum_map.size())
        {
            std::ostringstream oss;

            oss << " EString: Not all strings defined for enum "
                << typeid(T).name();

            throw std::runtime_error(oss.str());
        }
    }

    T _from_str(const std::string& sv) const
    {
        const auto it = enum_map.find(sv);

        if ( it == enum_map.end() )
        {
            return T::UNDEFINED;
        }

        return it->second;
    }

    const std::string& _to_str(T ev) const
    {
        const auto it = std::find_if(enum_map.begin(), enum_map.end(),
            [ev](const std::pair<std::string, T> & t) -> bool
            {
                return t.second == ev;
            });

        return it->first;
    }

private:
    const std::map<std::string, T> enum_map;
};

#endif /*ENUM_STRING_H*/