Function pyo3::ffi::PyUnicode_AsUTF8AndSize

pub unsafe extern "C" fn PyUnicode_AsUTF8AndSize(
    unicode: *mut PyObject, 
    size: *mut Py_ssize_t
) -> *const c_char

This is supported on Py_3_10, or Py_3_7 and non-Py_LIMITED_API only.