Function erlang_nif_sys::erlang_nif_sys_api::enif_map_iterator_get_pair

pub unsafe extern "C" fn enif_map_iterator_get_pair(
    env: *mut ErlNifEnv, 
    iter: *mut ErlNifMapIterator, 
    key: *mut ERL_NIF_TERM, 
    value: *mut ERL_NIF_TERM
) -> c_int

See enif_map_iterator_get_pair in the Erlang docs.