/span><a class="link" href="attr.html#spirit.qi.reference.auxiliary.attr.expression_semantics">Expression
            Semantics</a>
          </h6>
<p>
            Semantics of an expression is defined only where it differs from, or
            is not defined in <a class="link" href="../parser_concepts/primitiveparser.html" title="PrimitiveParser"><code class="computeroutput"><span class="identifier">PrimitiveParser</span></code></a>.
          </p>
<div class="informaltable"><table class="table">
<colgroup