Class exception

include/boost/leaf/exception.hpp:95–166

    template <class Ex>
    class exception final:
        public Ex,
        public exception_base,
        public error_id
    {
        mutable bool clear_current_error_;

        bool is_current_exception() const noexcept
        {
            return tls::read_current_error_id() == unsigned(error_id::value());
        }

        error_id get_error_id() const noexcept override
        {
            clear_current_error_ = false;
            return *this;
        }

        detail::type_name get_type_name() const override
        {
            return detail::get_type_name<Ex>();
        }

    public:

        exception( exception const & other ):
            Ex(other),
            exception_base(other),
            error_id(other),
            clear_current_error_(other.clear_current_error_)
        {
            other.clear_current_error_ = false;
        }

        exception( exception && other ) noexcept:
            Ex(std::move(other)),
            exception_base(std::move(other)),
            error_id(std::move(other)),
            clear_current_error_(std::move(other.clear_current_error_))
        {
            other.clear_current_error_ = false;
        }

        exception( error_id id, Ex const & ex ) noexcept:
            Ex(ex),
            error_id(id),
            clear_current_error_(true)
        {
            enforce_std_exception(*this);
        }

        exception( error_id id, Ex && ex ) noexcept:
            Ex(std::move(ex)),
            error_id(id),
            clear_current_error_(true)
        {
            enforce_std_exception(*this);
        }