Document Rcpp functions with default arguments that appear in their header files

[zhuxr11]

I am using roxygen 2 (//') to document Rcpp functions. As a common practice, functions shared across multiple files are defined in header file with default arguments (reference here). However, roxygen2 comments live in .cpp files (not the header files), where default parameters are not defined (and cannot be defined there even with the same default values, since this is not allowed in C++). In the end, the help page does not show any default parameters. I am wondering how this could be improved.

Example:

In test.h:

# ifndef TEST_CPP
# def TEST_CPP

#include <Rcpp.h>
using namespace Rcpp;

int timesTwo(int x = 0);

#endif

In test.cpp:

//' Multiply a number by two
//' 
//' @param x A single integer.
//' @export
// [[Rcpp::export]]
int timesTwo(int x) {
   return x * 2;
}

How could I get the help page show timesTwo(x = 0) in the usage section with roxygen2 comments?

[Enchufa2]

Sorry, but we can't help with that. This is a question for roxygen2, which is the package that handles such doc comments.

[eddelbuettel]

Agreed, and suggest we close this here. Rcpp plays the hand it was dealt. I sometimes write

//' @param x A single integer with default value of zero.

but that is of course manual.

[eddelbuettel]

Closing for inactivity, and, as stated, more-or-less being at the wrong repo.