<span class="identifier">size_t</span>
    <span class="identifier">available_write_bytes</span><span class="special">();</span>

    <span class="keyword">void</span>
    <span class="identifier">transfer_read_bytes</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">);</span>

    <span class="keyword">void</span>
    <span class="identifier">transfer_write_bytes</span><span class="special">(</spa