pub unsafe extern "system" fn clEnqueueReadBuffer(
    command_queue: cl_command_queue,
    buffer: cl_mem,
    blocking_read: cl_bool,
    offset: size_t,
    cb: size_t,
    ptr: *mut c_void,
    num_events_in_wait_list: cl_uint,
    event_wait_list: *const cl_event,
    event: *mut cl_event
) -> cl_int