Generating roxygen documentation for rcpp package do not work

Question

I generate a Rcpp package using Rcpp::Rcpp.package.skeleton() or using RStudio to test using roxygen2 documentation and changed the generated test cpp function in the folder src to:

#include <Rcpp.h>
using namespace Rcpp;

//’ Testing documentation with Rcpp
//’
//’ @param x        Character vector for testing  
//’ @param y        Numeric vector for testing more 
//’
//’ @return           List of x and y 
//’
//’ @export
// [[Rcpp::export]]
List rcpp_hello_world(CharacterVector x,NumericVector y) {

  List z            = List::create( x, y ) ;

  return z ;
}

I deleted the default .rd file from man, and I added Encoding: UTF-8 to the DESCRIPTION file as required by roxygen.

Then I run ctrl-shift-b (install and restart) on Rstudio

==> Rcpp::compileAttributes()

• Updated R/RcppExports.R

==> devtools::document(roclets=c('rd', 'collate', 'namespace'))

Updating testRcpp1 documentation First time using roxygen2. Upgrading automatically... Loading testRcpp1 Warning: The existing 'NAMESPACE' file was not generated by roxygen2, and will not be overwritten. Documentation completed

==> R CMD INSTALL ...

I check the man folder and the rd file is not generated, I can't find what I am doing wrong.

The sessionInfo() is :

R version 3.5.1 (2018-07-02)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 16.04.5 LTS

Matrix products: default
BLAS: /usr/lib/libblas/libblas.so.3.6.0
LAPACK: /usr/lib/lapack/liblapack.so.3.6.0

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=es_AR.UTF-8        LC_COLLATE=en_US.UTF-8    
 [5] LC_MONETARY=es_AR.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=es_AR.UTF-8       LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=es_AR.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] Rcpp_1.0.0    testRcpp1_1.0

loaded via a namespace (and not attached):
 [1] crayon_1.3.4      withr_2.1.2       rprojroot_1.3-2   assertthat_0.2.0  R6_2.2.2          backports_1.1.2  
 [7] magrittr_1.5      cli_1.0.0         rlang_0.2.1       rstudioapi_0.8    testthat_2.0.1    desc_1.2.0       
[13] tools_3.5.1       pkgload_1.0.2     yaml_2.1.19       compiler_3.5.1    sessioninfo_1.1.1

Answer 1

The problem seems to be the character you are using for comments. Your current code

//’ Testing documentation with Rcpp
//’
//’ @param x        Character vector for testing  
//’ @param y        Numeric vector for testing more 

uses ’ (which is the "right single quotation mark" character: code 146 or 0x92) rather than ' (which is the "apostrophe" character: code 39 or 0x27). The parser doesn't look for the right-handed quote symbol, only for the apostrophe. So just change to

//' Testing documentation with Rcpp
//'
//' @param x        Character vector for testing  
//' @param y        Numeric vector for testing more