t="_top">C++0X
        18.3.2.2</a> still specifies a (implementation-defined) representation
        for signaling NaN, and <code class="computeroutput"><span class="keyword">static</span> <span class="keyword">constexpr</span> <span class="keyword">bool</span> <span class="identifier">has_signaling_NaN</span></code> a method of checking
        if a floating-point type has a representation for signaling NaN.
      </p>
<p>
        But in practice, most platforms treat signaling NaNs in the same as quiet
 