fixed return value type in py::make_iterator

include/pybind11/pybind11.h

@@ -1006,7 +1006,7 @@ template <typename Iterator, typename... Extra> iterator make_iterator(Iterator
     if (!detail::get_type_info(typeid(state))) {
         class_<state>(handle(), "")
             .def("__iter__", [](state &s) -> state& { return s; })
-            .def("__next__", [](state &s) -> decltype(*std::declval<Iterator>()) & {
+            .def("__next__", [](state &s) -> decltype(*std::declval<Iterator>()) {
                 if (s.it == s.end)
                     throw stop_iteration();
                 return *s.it++;

include/pybind11/pytypes.h

@@ -285,7 +285,7 @@ public:
     bool operator==(const iterator &it) const { return *it == **this; }
     bool operator!=(const iterator &it) const { return *it != **this; }
 
-    const handle &operator*() const {
+    handle operator*() const {
         if (!ready && m_ptr) {
             auto& self = const_cast<iterator &>(*this);
             self.advance();