C++ (Cpp) variant::m_policy примеры использования

Пример #1

Файл: variant.cpp Проект: Victorique-GOSICK/rttr

void variant::swap(variant& other)
{
    if (this == &other)
        return;

    const bool is_this_valid = is_valid();
    const bool is_other_valid = other.is_valid();

    if (!is_this_valid && !is_other_valid)
        return;

    if (is_this_valid && is_other_valid)
    {
        detail::variant_data tmp_data;
        detail::variant_policy_func tmp_policy_func = other.m_policy;
        other.m_policy(detail::variant_policy_operation::SWAP, other.m_data, tmp_data);

        m_policy(detail::variant_policy_operation::SWAP, m_data, other.m_data);
        other.m_policy = m_policy;

        tmp_policy_func(detail::variant_policy_operation::SWAP, tmp_data, m_data);
        m_policy = tmp_policy_func;
    }
    else
    {
        detail::variant_data& full_data = is_this_valid ? m_data : other.m_data;
        detail::variant_data& empty_data = is_this_valid ? other.m_data : m_data;
        detail::variant_policy_func full_policy_func = is_this_valid ? m_policy : other.m_policy;

        full_policy_func(detail::variant_policy_operation::SWAP, full_data, empty_data);

        std::swap(m_policy, other.m_policy);
    }
}