assnc_1_1_nd_array.html">NdArray</a>&lt;<span class="keyword">decltype</span>(<a class="code hl_function" href="namespacenc_1_1special.html#a614d69a09535948c87124fe5662452dc">bessel_kn</a>(<a class="code hl_function" href="namespacenc.html#a8e78c416b2386411d8c6b5226bd4c78a">dtype1</a>{ 0 }, <a class="code hl_function" href="namespacenc.html#a8e78c416b2386411d8c6b5226bd4c78a">dtype2</a>{ 0 }))&gt; <a class="code hl_function" href="namespacenc.html#a8e78c416b2386411d8c6b5226bd4c78a">returnArray</a>(<a class="