Rcpp: porting C++ function into R, 'Rcpp.h' file not found

Question

I have some C++ code. I would like to make this an R package with Rcpp.

Here's what I'm doing:

1. Create a package framework by executing Rcpp.package.skeleton("myPackageName")
2. Run devtools::load_all() to see whether rcpp_hello_world() works after library(myPackageName). It does!
3. Take all C++ source code and copy this into /src. I can still use rcpp_hello_world() after running devtools::load_all() once again.
4. For each function in the C++ source code now residing in /src, simply do this:

(A) Put at the top of the .cpp file `

 #include <Rcpp.h>
using namespace Rcpp;

(B) Put before each function void this comment

 //[[Rcpp::export]]

Now, I foolishly think that if I run devtools::load_all(), the code with compile and those C++ functions will be accessible. This is incorrect.

Here's the error after load_all():

 1 warning generated.
sourcecode1.cc:2:10: fatal error: 'Rcpp.h' file not found
#include <Rcpp.h>
         ^
1 error generated.
make: *** [myPackageName] Error 1
ERROR: compilation failed for package ‘myPackageName’

It cannot find the header file Rcpp.h

(1) Is my procedure above incorrect in creating R packages directly from C++ code with Rcpp? This is what I've gathered from the book

(2) How can I solve this problem?

Answer 1

You need to run 'compileAttributes()' which RStudio would do for you too.

In short each time you alter or add interfaces, you need to run this function.