added const_generic_proxy

Author: romainfrancois

inst/include/Rcpp/Vector.h

@@ -63,6 +63,8 @@ template <int RTYPE> class SubMatrix ;
 #include <Rcpp/vector/string_proxy.h>
 #include <Rcpp/vector/const_string_proxy.h>
 }
+#include <Rcpp/vector/const_generic_proxy.h>
+
 
 #include <Rcpp/String.h>
 #include <Rcpp/vector/LazyVector.h>

inst/include/Rcpp/vector/00_forward_proxy.h

@@ -26,6 +26,7 @@ namespace internal{
 	template <int RTYPE> class string_proxy ;
 	template <int RTYPE> class const_string_proxy ;
 	template <int RTYPE> class generic_proxy ;
+	template <int RTYPE> class const_generic_proxy ;
 	template <int RTYPE> class simple_name_proxy ; 
 	template <int RTYPE> class string_name_proxy ;
 	template <int RTYPE> class generic_name_proxy ;

inst/include/Rcpp/vector/const_generic_proxy.h

@@ -0,0 +1,64 @@
+// const_generic_proxy.h: Rcpp R/C++ interface class library -- 
+//
+// Copyright (C) 2013 Romain Francois
+//
+// This file is part of Rcpp.
+//
+// Rcpp is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 2 of the License, or
+// (at your option) any later version.
+//
+// Rcpp is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Rcpp.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef Rcpp__vector__const_generic_proxy_h
+#define Rcpp__vector__const_generic_proxy_h
+ 
+namespace Rcpp{
+namespace internal{
+    
+    template <int RTYPE> 
+	class const_generic_proxy{
+		public:
+			typedef typename ::Rcpp::Vector<RTYPE> VECTOR ;
+			
+			const_generic_proxy(): parent(0), index(-1){}
+			
+			const_generic_proxy( const const_generic_proxy& other ) : 
+				parent(other.parent), index(other.index){} ;
+			
+			const_generic_proxy( const VECTOR& v, int i ) : parent(&v), index(i){} ;
+		
+			operator SEXP() const { 
+			    return get() ;
+			}
+			
+			template <typename U> operator U() const {
+				return ::Rcpp::as<U>(get()) ;
+			}
+			
+			// helping the compiler (not sure why it can't help itself)
+			operator bool() const { return ::Rcpp::as<bool>(get()) ; }
+			operator int() const { return ::Rcpp::as<int>(get()) ; }
+			
+			const VECTOR* parent; 
+			int index ;
+			
+		private:
+			
+		    inline SEXP get() const { 
+			    return VECTOR_ELT(*parent, index ); 
+			} 
+		
+	}  ;
+	
+}
+}
+
+#endif

inst/include/Rcpp/vector/proxy.h

@@ -230,6 +230,12 @@ namespace traits {
 	template<> struct r_vector_const_proxy<STRSXP> {
 		typedef ::Rcpp::internal::const_string_proxy<STRSXP> type ;
 	} ;
+	template<> struct r_vector_const_proxy<VECSXP> {
+		typedef ::Rcpp::internal::const_generic_proxy<VECSXP> type ;
+	} ;
+	template<> struct r_vector_const_proxy<EXPRSXP> {
+		typedef ::Rcpp::internal::const_generic_proxy<EXPRSXP> type ;
+	} ;
 
 	template <int RTYPE>
 	struct r_vector_iterator {