value.h

#ifndef _VALUE_H
#define _VALUE_H
/*
 * Fledge storage client.
 *
 * Copyright (c) 2018 OSisoft, LLC
 *
 * Released under the Apache 2.0 Licence
 *
 * Author: Mark Riddoch
 */
#include <string>
#include <sstream>
#include <iostream>


class UpdateValue {
    public:
        enum UpdateType {
            StringType,
            IntType,
            DoubleType,
            JSONType };
        UpdateValue(const std::string& column, const std::string& value) :
                m_column(column), m_value.str(value), m_type(UpdateValue::StringType) {};
        UpdateValue(const std::string& column, const int value) :
                m_column(column), m_value.ival(value), m_type(UpdateValue::IntType) {};
        UpdateValue(const std::string& column, const double value) :
                m_column(column), m_value.fval(value), m_type(UpdateValue::DoubleType) {};
        ~UpdateValue() {};
        std::string toJSON()
        {
        std::ostringstream json;

            json << "\"" << m_column << "\" : ";
            switch (m_type)
            {
            case UpdateValue::StringType:
                json << "\"" << m_value.str << "\"";
                break;
            case UpdateValue::IntType:
                json << m_value.ival;
                break;
            case UpdateValue::DoubleType:
                json << m_value.fval;
                break;
            case UpdateValue::JSONType:
                json << m_value.str;
                break;
            }
            return json.str();
        }
    private:
        const std::string   m_column;
        enum UpdateType     m_type;
        union {
            std::string str;
            int     ival;
            double      fval;
        }           m_value;
};
#endif