Decay const qualifiers in is_pod_struct<>

include/pybind11/numpy.h

@@ -29,6 +29,8 @@ NAMESPACE_BEGIN(pybind11)
 namespace detail {
 template <typename type, typename SFINAE = void> struct npy_format_descriptor { };
 template <typename type> struct is_pod_struct;
+template <typename T> using decay_cv_ref =
+    typename std::remove_cv<typename std::remove_reference<T>::type>::type;
 
 struct npy_api {
     enum constants {
@@ -321,14 +323,15 @@ template <typename T, size_t N> struct is_std_array<std::array<T, N>> : std::tru
 template <typename T>
 struct is_pod_struct {
     enum { value = std::is_pod<T>::value && // offsetof only works correctly for POD types
+           !std::is_reference<T>::value &&
            !std::is_array<T>::value &&
            !is_std_array<T>::value &&
            !std::is_integral<T>::value &&
-           !std::is_same<T, float>::value &&
-           !std::is_same<T, double>::value &&
-           !std::is_same<T, bool>::value &&
-           !std::is_same<T, std::complex<float>>::value &&
-           !std::is_same<T, std::complex<double>>::value };
+           !std::is_same<typename std::remove_cv<T>::type, float>::value &&
+           !std::is_same<typename std::remove_cv<T>::type, double>::value &&
+           !std::is_same<typename std::remove_cv<T>::type, bool>::value &&
+           !std::is_same<typename std::remove_cv<T>::type, std::complex<float>>::value &&
+           !std::is_same<typename std::remove_cv<T>::type, std::complex<double>>::value };
 };
 
 template <typename T> struct npy_format_descriptor<T, typename std::enable_if<std::is_integral<T>::value>::type> {