modbusCell.hpp

// Modbus for c++ <https://github.com/Mazurel/Modbus>
// Copyright (c) 2020 Mateusz Mazur aka Mazurel
// Licensed under: MIT License <http://opensource.org/licenses/MIT>
 
#pragma once
 
#include <cstdint>
#include <stdexcept>
#include <variant>
 
namespace MB {
class ModbusCell {
  private:
    std::variant<uint16_t, bool> _value;
 
  public:
    constexpr ModbusCell() = default;
 
    constexpr ModbusCell(uint16_t reg) : _value(reg) {};
 
    constexpr ModbusCell(bool coil) : _value(coil) {};
 
    ModbusCell(const ModbusCell &other) noexcept            = default;
    ModbusCell &operator=(const ModbusCell &other) noexcept = default;
    ModbusCell &operator=(ModbusCell &&other) noexcept      = default;
 
    [[nodiscard]] static ModbusCell initReg(uint16_t reg) { return ModbusCell(reg); }
 
    [[nodiscard]] static ModbusCell initCoil(bool coil) { return ModbusCell(coil); }
 
    [[nodiscard]] bool isCoil() const { return std::holds_alternative<bool>(_value); };
 
    [[nodiscard]] bool isReg() const { return std::holds_alternative<uint16_t>(_value); };
 
    bool &coil() {
        if (isReg())
            _value = static_cast<bool>(std::get<uint16_t>(_value));
        return std::get<bool>(_value);
    };
 
    uint16_t &reg() {
        if (isCoil())
            _value = static_cast<uint16_t>(std::get<bool>(_value));
        return std::get<uint16_t>(_value);
    };
 
    [[nodiscard]] const bool &coil() const { return std::get<bool>(_value); };
 
    [[nodiscard]] const uint16_t &reg() const { return std::get<uint16_t>(_value); };
 
    [[nodiscard]] std::string toString() const noexcept {
        return isCoil() ? ((coil()) ? "true" : "false") : std::to_string(reg());
    }
};
} // namespace MB