l" title="Struct template multiply_typeof_helper">boost::units::multiply_typeof_helper</a><span class="special">&lt;</span> <a class="link" href="../units/unit.html" title="Class template unit">boost::units::unit</a><span class="special">&lt;</span> <span class="identifier">Dim1</span><span class="special">,</span> <span class="identifier">System1</span> <span class="special">&gt;</span><span class="special">,</span> <a class="link" href="../units/quantity.html" title="Class template quantity">boost::units: