class="keyword">using</span> <span class="identifier">phrase_context_type</span> <span class="special">=</span> <span class="identifier">x3</span><span class="special">::</span><span class="identifier">phrase_parse_context</span><span class="special">&lt;</span><span class="identifier">x3</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">::</span><span class="identifier">space_type</span><span class="special">&gt;::</span><span class="identifier">type</span><spa