Method has_fields

dlib/external/pybind11/include/pybind11/numpy.h:701–701

    /// Returns true for structured data types.
#ifdef PYBIND11_NUMPY_1_ONLY
    bool has_fields() const { return detail::array_descriptor_proxy(m_ptr)->names != nullptr; }
#else
    bool has_fields() const {
        if (detail::npy_api::get().PyArray_RUNTIME_VERSION_ < 0x12) {