Adds infrastructure commonly needed when using compiled code:
Creates src/
Adds required packages to DESCRIPTION
May create an initial placeholder .c or .cpp file
Creates Makevars and Makevars.win files (use_rcpp_armadillo() only)
use_rcpp(name = NULL)use_rcpp_armadillo(name = NULL)
use_rcpp_eigen(name = NULL)
use_c(name = NULL)
If supplied, creates and opens src/name.{c,cpp}.
When using compiled code, please note that there must be at least one file
inside the src/ directory prior to building the package. As a result,
if an empty src/ directory is detected, either a .c or .cpp file will
be added.