operator SEXP has to be const for it to work with wrap

Author: romainfrancois

ChangeLog

@@ -1,3 +1,8 @@
+2013-10-28 Romain Francois <romain@r-enthusiasts.com>
+
+        * include/Rcpp/protection/Armor.h : Armor::operator SEXP has to be const
+        for it to work properly with wrap. 
+
 2013-10-27  Dirk Eddelbuettel  <edd@debian.org>
 
         * DESCRIPTION: Release 0.10.6

inst/include/Rcpp/protection/Armor.h

@@ -30,7 +30,7 @@ namespace Rcpp {
 
         template <typename U> Armor( U x );
 
-        inline operator SEXP(){
+        inline operator SEXP() const {
             return data ;
         }