title: Rstudio Roxygen2 @importFrom parsing function header
body: <p>I am building a package with Rcpp using Rstudio. Everything was working fine until I added the markup for documentation to my function file. I hope I am overlooking something obvious.</p>
  
  <p>Here is my R function file:</p>
  
  <pre><code>#' @useDynLib tablr
  #' @importFrom Rcpp sourceCpp
  #'
  #' fast.table
  #'
  #' C++ implementation of the R table function. Only supports numeric
  #' vectors. Does not currently handle NAs.
  #'
  #' @param x1 Variable 1
  #' @param x2 Variable 2
  #' @return A table object equal in every way to an R table object with the same
  #' inputs
  #'
  #' @export fast.table
  fast.table &lt;- function(x1, x2) {
    nms &lt;- c(deparse(substitute(x1)), deparse(substitute(x2)))
    cpp_table(as.numeric(x1), as.numeric(x2), as.character(nms))
  }
  </code></pre>
  
  <p>And after running <code>devtools::document()</code> this is what the Namespace file looks like:</p>
  
  <pre><code># Generated by roxygen2 (4.0.2): do not edit by hand
  
  export(fast.table)
  importFrom(Rcpp,"C++")
  importFrom(Rcpp,Does)
  importFrom(Rcpp,NAs.)
  importFrom(Rcpp,Only)
  importFrom(Rcpp,R)
  importFrom(Rcpp,currently)
  importFrom(Rcpp,fast.table)
  importFrom(Rcpp,function.)
  importFrom(Rcpp,handle)
  importFrom(Rcpp,implementation)
  importFrom(Rcpp,not)
  importFrom(Rcpp,numeric)
  importFrom(Rcpp,of)
  importFrom(Rcpp,sourceCpp)
  importFrom(Rcpp,supports)
  importFrom(Rcpp,table)
  importFrom(Rcpp,the)
  importFrom(Rcpp,vectors.)
  useDynLib(tablr)
  </code></pre>
  
  <p>As you can see, the <code>@importFrom</code> tag is parsing the function header text and trying to import each 'word' from the <code>Rcpp</code> package.</p>
  
  <p>The error message after running <code>devtools::document()</code>:</p>
  
  <pre><code>Error: object 'C++' is not exported by 'namespace:Rcpp'
  Execution halted
  
  Exited with status 1.
  </code></pre>
  
  <p>And the Session Info:</p>
  
  <pre><code>&gt; devtools::session_info()
  Session info----------------------------------------------------------------------------------
   setting  value                       
   version  R version 3.1.1 (2014-07-10)
   system   x86_64, mingw32             
   ui       RStudio (0.98.1049)         
   language (EN)                        
   collate  English_United States.1252  
   tz       America/Chicago             
  
  Packages--------------------------------------------------------------------------------------
   package    * version date       source        
   devtools     1.6.1   2014-10-07 CRAN (R 3.1.1)
   Rcpp         0.11.3  2014-09-29 CRAN (R 3.1.1)
   roxygen2     4.0.2   2014-09-02 CRAN (R 3.1.1)
   rstudioapi   0.1     2014-03-27 CRAN (R 3.1.1)
   stringr      0.6.2   2012-12-06 CRAN (R 3.1.0)
   tablr      * 0.1     &lt;NA&gt;       local         
  </code></pre>