[Rcpp-devel] Can an Rcpp package include Fortran code?

[Dirk Eddelbuettel]

On 6 October 2016 at 12:19, Avraham Adler wrote:
| Has anyone successfully created a package that uses Rcpp for C++ code
| and which also has Fortran code? I'm experimenting with comparing
| Fortran and C++ and if I could use Rcpp to handle the C++ portion, it
| would reduce the steepness of the learning curve.
| 
| However, I haven't had success. The following C++ and Fortran snippets
| compile properly separately—the C++ as part of Rcpp and the Fortran
| using R CMD SHLIB and dynload—and the R snippets call them properly,
| but when I put both the .cpp and .f95 files in /src, I get the huge
| error posted below the files.
| 
| Am I missing something simple or will having C++ and Fortran code in
| the same package prevent the use of Rcpp and require the old methods
| of calling compiled code?

I was about to say 'sure, why not' when I remembered that Writiing R
Extension has something to say about this in section 1.2.4:

     There is no guarantee that C++11 can be used in a package in
  combination with any other compiled language (even C), as the C++11
  compiler may be incompatible with the native compilers for the platform.
  (There are known problems mixing C++11 with Fortran.)

but then this warning is just about C++11 and Fortran.

That said, your description above suggests that you are "simply" too
optimistic about 'Rcpp Attributes' -- those do not aim to support all
languages. They provide a (very powerful) convenience tool for Rcpp. And
hence C++.

If it works in a package, stick with a package. That gets you different
compilation units, and hopefully sane linking.

Dirk

-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org