Memory error in assigning int literal to NumericVector

[kevinushey]

Ie:

#include <Rcpp.h>
using namespace Rcpp;

// [[Rcpp::export]]
NumericVector test() {
  NumericVector m(1);
  m = 1;
  return m;
}

/*** R
gctorture(TRUE)
test()
gctorture(FALSE)
*/

produces the exception:

Error in test() : unimplemented type 'double' in 'coerceToReal'

I very strongly suspect this is the same error reported a long time back in http://lists.r-forge.r-project.org/pipermail/rcpp-devel/2011-June/002545.html.

Definitely, this code is an example of something you shouldn't do, but Rcpp tries to be helpful and make it work anyway.

I imagine the bug is due to the code here, in vector/Vector.h:

// anything else
template <typename T>
inline void assign_object( const T& x, traits::false_type ) {
    Storage::set__( r_cast<RTYPE>( wrap(x) ) ) ;

Because the wrap(x)-ed object is not protected, it gets cleaned up before r_cast does its work.

[eddelbuettel]

Chapeau -- good work.