Function ceph_rust::rados_read_op_exec_user_buf

pub unsafe extern fn rados_read_op_exec_user_buf(read_op: rados_read_op_t, cls: *const c_char, method: *const c_char, in_buf: *const c_char, in_len: size_t, out_buf: *mut c_char, out_len: size_t, used_len: *mut size_t, prval: *mut c_int)