title: Rcpp function with no argument
body: <p>I am developing a R package using Rcpp, and now I an trying to include the following c++ function without input arguments:</p>
  
  <pre><code>int printVariables() {
      // Code
      return 0;
  }
  </code></pre>
  
  <p>I have in my <code>RcppExports.cpp</code> the next function:</p>
  
  <pre><code>int printVariables();
  RcppExport SEXP printVariables() {
  BEGIN_RCPP
      Rcpp::RObject __result;
      Rcpp::RNGScope __rngScope;
      __result = Rcpp::wrap(printVariables());
      return __result;
  END_RCPP
  }
  </code></pre>
  
  <p>Finally, in the RcppExports.R I have an entry as follows:</p>
  
  <pre><code>printVariables &lt;- function() {
      .Call('printVariables', PACKAGE = 'my_package')
  }
  </code></pre>
  
  <p>When I compile the code I get this error:</p>
  
  <pre><code>RcppExports.cpp: In function ‘SEXPREC* printVariables()’:
  RcppExports.cpp:54:37: error: ambiguating new declaration of ‘SEXPREC* printVariables()’
   RcppExport SEXP printVariables() {
  RcppExports.cpp:53:5: note: old declaration ‘int printVariables()’
   int printVariables();
  </code></pre>
  
  <p>Anyone knows how can I solve that issue?</p>