Test to demonstrate compiler behavior change in Xcode 7 / clang 3.7.

test.cpp

@@ -91,6 +91,14 @@ int main(int argc, char **argv) {
     assert(uni[0].string_value().size() == (sizeof utf8) - 1);
     assert(memcmp(uni[0].string_value().data(), utf8, sizeof utf8) == 0);
 
+    // Demonstrates the behavior change in Xcode 7 / Clang 3.7 described
+    // here: https://llvm.org/bugs/show_bug.cgi?id=23812
+    Json nested_array = Json::array { Json::array { 1, 2, 3 } };
+    assert(nested_array.is_array());
+    assert(nested_array.array_items().size() == 1);
+    assert(nested_array.array_items()[0].is_array());
+    assert(nested_array.array_items()[0].array_items().size() == 3);
+
     Json my_json = Json::object {
         { "key1", "value1" },
         { "key2", false },