sfinae

#include <QObject>
#include <QPointer>

template <typename T, typename = void>
struct is_deserializeable : std::false_type {};

template <typename T>
struct is_deserializeable <T, decltype(std::declval<QDataStream&>() >> std::declval<T&>())> : std::true_type {};

template <typename T, typename = std::enable_if_t<is_deserializeable<T>::value>>
class Property
{
public:
    Property(FruitWrapper* obj)
        : m_obj{obj} { }
    void setValue(const QByteArray& array) noexcept
    {
        if (array.isEmpty()) { return; }
        T value;
        QDataStream dataStream{array};
        dataStream >> value;
        if (value != m_value) {
            m_value = std::move(value);
            emit m_obj->valueChanged();
        }
    }

    T getValue() const noexcept { return m_value; }

private:
    T m_value = T();
    QPointer<FruitWrapper> m_obj;
};

class FruitWrapper: public QObject
{
    Q_OBJECT
    Q_ENUMS(FruitType)
    Q_PROPERTY(FruitType value READ getValue NOTIFY valueChanged)
public:
    enum class Fruit: qint32 {
        APPLE = 0x0000,
        PEACH = 0x0001,
        BANANA = 0x0002
    };
    Data(QObject *parent = nullptr);
    void setValue(const QByteArray &array) override;
    Turn getValue() const;

private:
    friend QDataStream& operator<<(QDataStream& out, const FruitWrapper::Fruit& fruit);
    friend QDataStream& operator>>(QDataStream& in, FruitWrapper::Fruit& fruit);

    _detail::Property<Enum> m_impl;
};

QDataStream& operator<<(QDataStream& out, const FruitWrapper::Fruit& fruit)
{
    out << static_cast<qint32>(fruit);
    return out;
}
QDataStream& operator>>(QDataStream& in, FruitWrapper::Fruit& fruit)
{
    qint32 v;
    in >> v;
    fruit = static_cast<FruitWrapper::Fruit>(v);
    return in;
}