# 16 Fortran / C / C++ / Python / Third-Party Code

If the package contains C or Fortran code, it should adhere to the standards and methods described in the System and foreign language interfaces section of the Writing R Extensions manual.

## 16.1 Makevars

Make judicious use of the Makevars and Makefile files within a package. These are often not required at all (See the Configure and cleanup section of the Writing R Extensions manual).

## 16.2 Fortran

Consider utilizing the dotCall64 CRAN package.

## 16.3 C / C++

The Rcpp CRAN package allows seamless integration of C++ with R, and is cross-platform. The package affords many of the same benefits for the R C interface that make C++ so appealing as a language, while eliminating many of the pitfalls of programming to the R interface.

The package is well documented, and has an extensive repository of working examples for many tasks: the Rcpp Gallery.

## 16.4 Python

The basilisk package is encouraged to integrate python into R packages. Alternatively reticulate may be utilized but basilisk is preferred.

## 16.5 Other

Use of external libraries whose functionality is redundant with libraries already supported is strongly discouraged. In cases where the external library is complex, the author may need to supply pre-built binary versions for some platforms.

By including third-party code a package maintainer assumes responsibility for maintenance of that code. Part of the maintenance responsibility includes keeping the code up to date as bug fixes and updates are released for the mainline third-party project.