an class="im">&lt;Rcpp.h&gt;</span></span>
<span id="cb3-3"><a href="030_basic_usage.html#cb3-3"></a><span class="kw">using</span> <span class="kw">namespace</span> Rcpp;</span>
<span id="cb3-4"><a href="030_basic_usage.html#cb3-4"></a></span>
<span id="cb3-5"><a href="030_basic_usage.html#cb3-5"></a><span class="co">// [[Rcpp::export]]</span></span>
<span id="cb3-6"><a href="030_basic_usage.html#cb3-6"></a><span class="dt">double</span> rcpp_sum(NumericVector v){</span>
<span id="cb3-7"><a href="030_basic_