generate new vector to hold results

Author: kevinushey

inst/include/Rcpp/vector/Subsetter.h

@@ -228,22 +228,23 @@ class SubsetProxy {
 
 public:
 
-#define RCPP_GENERATE_SUBSET_PROXY_OPERATOR(__OPERATOR__)                      \
-    template <int RTYPE_OTHER, template <class> class StoragePolicyOther,      \
-              int RHS_RTYPE_OTHER, bool RHS_NA_OTHER, typename RHS_T_OTHER>    \
-    SubsetProxy& operator __OPERATOR__ (                                       \
-        const SubsetProxy<RTYPE_OTHER, StoragePolicyOther, RHS_RTYPE_OTHER,    \
-                          RHS_NA_OTHER, RHS_T_OTHER>& other) {                 \
-        if (other.indices_n == 1) {                                            \
-            for (int i = 0; i < indices_n; ++i)                                \
-                lhs[indices[i]] __OPERATOR__ ## = other.lhs[other.indices[0]]; \
-        } else if (indices_n == other.indices_n) {                             \
-            for (int i = 0; i < indices_n; ++i)                                \
-                lhs[indices[i]] __OPERATOR__ ## = other.lhs[other.indices[i]]; \
-        } else {                                                               \
-            stop("index error");                                               \
-        }                                                                      \
-        return *this;                                                          \
+#define RCPP_GENERATE_SUBSET_PROXY_OPERATOR(__OPERATOR__)                             \
+    template <int RTYPE_OTHER, template <class> class StoragePolicyOther,             \
+              int RHS_RTYPE_OTHER, bool RHS_NA_OTHER, typename RHS_T_OTHER>           \
+    Vector<RTYPE, StoragePolicy> operator __OPERATOR__ (                              \
+        const SubsetProxy<RTYPE_OTHER, StoragePolicyOther, RHS_RTYPE_OTHER,           \
+                          RHS_NA_OTHER, RHS_T_OTHER>& other) {                        \
+        Vector<RTYPE, StoragePolicy> result(indices_n);                               \
+        if (other.indices_n == 1) {                                                   \
+            for (int i = 0; i < indices_n; ++i)                                       \
+                result[i] = lhs[indices[i]] __OPERATOR__ other.lhs[other.indices[0]]; \
+        } else if (indices_n == other.indices_n) {                                    \
+            for (int i = 0; i < indices_n; ++i)                                       \
+                result[i] = lhs[indices[i]] __OPERATOR__ other.lhs[other.indices[i]]; \
+        } else {                                                                      \
+            stop("index error");                                                      \
+        }                                                                             \
+        return result;                                                                \
     }
 
 RCPP_GENERATE_SUBSET_PROXY_OPERATOR(+)