Add tests for nested recarrays
diff --git a/example/example20.cpp b/example/example20.cpp
index c22eb21..2535b25 100644
--- a/example/example20.cpp
+++ b/example/example20.cpp
@@ -30,23 +30,36 @@
 struct NestedStruct {
     Struct a;
     PackedStruct b;
-};
+} __attribute__((packed));
+
+template <typename T>
+py::array mkarray_via_buffer(size_t n) {
+    return py::array(py::buffer_info(nullptr, sizeof(T),
+                                     py::format_descriptor<T>::value(),
+                                     1, { n }, { sizeof(T) }));
+}
 
 template <typename S>
 py::array_t<S> create_recarray(size_t n) {
-    auto arr = py::array(py::buffer_info(nullptr, sizeof(S),
-                                         py::format_descriptor<S>::value(),
-                                         1, { n }, { sizeof(S) }));
-    auto buf = arr.request();
-    auto ptr = static_cast<S*>(buf.ptr);
+    auto arr = mkarray_via_buffer<S>(n);
+    auto ptr = static_cast<S*>(arr.request().ptr);
     for (size_t i = 0; i < n; i++) {
-        ptr[i].x = i % 2;
-        ptr[i].y = i;
-        ptr[i].z = i * 1.5;
+        ptr[i].x = i % 2; ptr[i].y = (uint32_t) i; ptr[i].z = (float) i * 1.5f;
     }
     return arr;
 }
 
+py::array_t<NestedStruct> create_nested(size_t n) {
+    auto arr = mkarray_via_buffer<NestedStruct>(n);
+    auto ptr = static_cast<NestedStruct*>(arr.request().ptr);
+    for (size_t i = 0; i < n; i++) {
+        ptr[i].a.x = i % 2; ptr[i].a.y = (uint32_t) i; ptr[i].a.z = (float) i * 1.5f;
+        ptr[i].b.x = (i + 1) % 2; ptr[i].b.y = (uint32_t) (i + 1); ptr[i].b.z = (float) (i + 1) * 1.5f;
+    }
+    return arr;
+
+}
+
 void init_ex20(py::module &m) {
     PYBIND11_DTYPE(Struct, x, y, z);
     PYBIND11_DTYPE(PackedStruct, x, y, z);
@@ -54,4 +67,5 @@
 
     m.def("create_rec_simple", &create_recarray<Struct>);
     m.def("create_rec_packed", &create_recarray<PackedStruct>);
+    m.def("create_rec_nested", &create_nested);
 }
diff --git a/example/example20.py b/example/example20.py
index 0e42c68..83725b5 100644
--- a/example/example20.py
+++ b/example/example20.py
@@ -2,7 +2,7 @@
 from __future__ import print_function
 
 import numpy as np
-from example import create_rec_simple, create_rec_packed
+from example import create_rec_simple, create_rec_packed, create_rec_nested
 
 
 def check_eq(arr, data, dtype):
@@ -14,12 +14,25 @@
 packed_dtype = np.dtype([('x', '?'), ('y', 'u4'), ('z', 'f4')])
 
 for func, dtype in [(create_rec_simple, simple_dtype), (create_rec_packed, packed_dtype)]:
+    arr = func(0)
+    assert arr.dtype == dtype
+    check_eq(arr, [], simple_dtype)
+    check_eq(arr, [], packed_dtype)
+
     arr = func(3)
     assert arr.dtype == dtype
     check_eq(arr, [(False, 0, 0.0), (True, 1, 1.5), (False, 2, 3.0)], simple_dtype)
     check_eq(arr, [(False, 0, 0.0), (True, 1, 1.5), (False, 2, 3.0)], packed_dtype)
 
-    arr = func(0)
-    assert arr.dtype == dtype
-    check_eq(arr, [], simple_dtype)
-    check_eq(arr, [], packed_dtype)
+
+nested_dtype = np.dtype([('a', simple_dtype), ('b', packed_dtype)])
+
+arr = create_rec_nested(0)
+assert arr.dtype == nested_dtype
+check_eq(arr, [], nested_dtype)
+
+arr = create_rec_nested(3)
+assert arr.dtype == nested_dtype
+check_eq(arr, [((False, 0, 0.0), (True, 1, 1.5)),
+               ((True, 1, 1.5), (False, 2, 3.0)),
+               ((False, 2, 3.0), (True, 3, 4.5))], nested_dtype)