EnumValue.h

//
// Copyright 2015 - 2025 (C). Alex Robenko. All rights reserved.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
#pragma once
 
#include "comms/ErrorStatus.h"
#include "comms/field/basic/IntValue.h"
#include "comms/field/tag.h"
 
#include <type_traits>
 
namespace comms
{
 
namespace field
{
 
namespace basic
{
 
template <typename TFieldBase, typename T>
class EnumValue : public TFieldBase
{
    static_assert(std::is_enum<T>::value, "T must be enum");
 
    using UnderlyingType = typename std::underlying_type<T>::type;
 
    using BaseImpl = TFieldBase;
 
    using IntValueField =
        comms::field::basic::IntValue<
            BaseImpl,
            UnderlyingType
        >;
 
    using IntValueType = typename IntValueField::ValueType;
public:
 
    using ValueType = T;
 
    using SerialisedType = typename IntValueField::ValueType;
 
    using ScalingRatio = typename IntValueField::ScalingRatio;
 
    using CommsTag = comms::field::tag::Enum;
 
    EnumValue() = default;
 
    explicit EnumValue(ValueType val)
      : m_value(val)
    {
    }
 
    EnumValue(const EnumValue&) = default;
    EnumValue(EnumValue&&) = default;
    ~EnumValue() noexcept = default;
 
    EnumValue& operator=(const EnumValue&) = default;
    EnumValue& operator=(EnumValue&&) = default;
 
    const ValueType& value() const
    {
        return m_value;
    }
 
    ValueType& value()
    {
        return m_value;
    }
 
    const ValueType& getValue() const
    {
        return value();
    }
 
    template <typename U>
    void setValue(U&& val)
    {
        value() = static_cast<ValueType>(std::forward<U>(val));
    }    
 
    static constexpr std::size_t length()
    {
        return IntValueField::length();
    }
 
    static constexpr std::size_t minLength()
    {
        return length();
    }
 
    static constexpr std::size_t maxLength()
    {
        return length();
    }
 
    static constexpr SerialisedType toSerialised(ValueType val)
    {
        return IntValueField::toSerialised(static_cast<IntValueType>(val));
    }
 
    static constexpr ValueType fromSerialised(SerialisedType val)
    {
        return static_cast<ValueType>(IntValueField::fromSerialised(val));
    }
 
    template <typename TIter>
    ErrorStatus read(TIter& iter, std::size_t size)
    {
        IntValueField intField;
        auto es = intField.read(iter, size);
        if (es == ErrorStatus::Success) {
            m_value = static_cast<decltype(m_value)>(intField.value());
        }
        return es;
    }
 
    template <typename TIter>
    void readNoStatus(TIter& iter)
    {
        IntValueField intField;
        intField.readNoStatus(iter);
        m_value = static_cast<decltype(m_value)>(intField.value());
    }
 
    template <typename TIter>
    ErrorStatus write(TIter& iter, std::size_t size) const
    {
        return IntValueField(static_cast<IntValueType>(m_value)).write(iter, size);
    }
 
    template <typename TIter>
    void writeNoStatus(TIter& iter) const
    {
        IntValueField(static_cast<IntValueType>(m_value)).writeNoStatus(iter);
    }
 
private:
    ValueType m_value = static_cast<ValueType>(0);
};
 
}  // namespace basic
 
}  // namespace field
 
}  // namespace comms