add some neat stuff I just learned about

nifty_gridder.cc

@@ -171,7 +171,7 @@ void checkArray(const py::array &arr, const char *aname,
 template<typename T> pyarr<T> provideArray(py::object &in,
   const vector<size_t> &shape)
   {
-  if (in.is(None))
+  if (in.is_none())
     {
     auto tmp_ = makeArray<T>(shape);
     size_t sz = size_t(tmp_.size());
@@ -188,7 +188,7 @@ template<typename T> pyarr<T> provideArray(py::object &in,
 template<typename T> pyarr_c<T> provideCArray(py::object &in,
   const vector<size_t> &shape)
   {
-  if (in.is(None))
+  if (in.is_none())
     {
     auto tmp_ = makeArray<T>(shape);
     size_t sz = size_t(tmp_.size());