template<class MutableBufferSequence>
    std::size_t read(MutableBufferSequence const&)
    {
        throw std::exception{};
    }

    void
    example()
    {
        std::string s;
        assert(s.empty());
        try
        {
            auto b = boost::asio::dynamic_buffer(s);
            b.commit(read(b.prepare(32)));
        }
        catch(std::exception const&)
        {
            assert(s.empty()); // fails
        }
    }