Support ListOfs of ListOfs

Author: kevinushey

inst/include/Rcpp/vector/ChildVector.h

@@ -33,7 +33,7 @@ class ChildVector : public T {
         i(i_) {}
 
     ChildVector(const ChildVector& other):
-        T(other),
+        T(wrap(other)),
         parent(other.parent),
         i(other.i) {}
 

inst/include/Rcpp/vector/ListOf.h

@@ -36,7 +36,8 @@ class ListOf {
     template <typename U>
     ListOf(const U& data_): list(data_) {}
 
-    ListOf(const ListOf& other): list(other.list) {}
+    ListOf(const ListOf& other): list(other.get()) {}
+
     ListOf& operator=(const ListOf& other) {
         if (this != &other) {
             list = other.list;

inst/unitTests/cpp/ListOf.cpp

@@ -88,3 +88,8 @@ int test_sub_calls(NVList x) {
     int sz = x[0].size() + x[1].size() + x[2].size();
     return sz;
 }
+
+// [[Rcpp::export]]
+NumericVector test_nested_listof(ListOf< ListOf<NumericVector> > x) {
+  return x[0][0];
+}

inst/unitTests/runit.ListOf.R

@@ -67,4 +67,11 @@ if (.runThisTest) {
         checkEquals(test_sub_calls( list(1, 2, 3) ), 3)
     }
 
+    test.ListOf.nested <- function() {
+        checkEquals(
+            test_nested_listof( list(list(1)) ),
+            1
+        )
+    }
+
 }