[Rcpp-devel] #ifdef'd out // [[Rcpp::export]]

Greg Minshall minshall at umich.edu
Sun Feb 24 17:35:44 CET 2013

hi.  first, i should mention that i think Rcpp is amazing!  i'm enjoying
the learning process, and it speeds up my formerly-R code greatly.
(some trivial image processing thing that i was only doing in R in order
to combine two learning activities into one.)

but... ;-)

if i sourceCpp() the following code:
#include <Rcpp.h>

#if 0
// [[Rcpp::export]]
int foo() {
    return 3;
#endif /* 0 */
i get this set of error messages
> sourceCpp("foo.cc")
foo.cc: In function 'SEXPREC* sourceCpp_15583_foo()':
foo.cc:16: error: 'foo' was not declared in this scope
make: *** [foo.o] Error 1
flag-sort -r g++ -I/sw/Library/Frameworks/R.framework/Versions/2.15/Resources/include -DNDEBUG  -I/sw/include  -I"/Users/minshall/Library/R/2.15/library/Rcpp/include"   -fPIC  -g -O2  -c foo.cc -o foo.o 
Error in sourceCpp("foo.cc") : Error 1 occurred building shared library.

btw, thanks for pointing me at "verbose=TRUE" in sourceCpp().  i was
wondering how to get something like "g++ -E".  (and, it shows me what's
going on under the hood in this case.)


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