%%--------------------------------------------------------------------
%% Copyright (c) 2019-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------

-type(maybe(T) :: undefined | T).

-type(startlink_ret() :: {ok, pid()} | ignore | {error, term()}).

-type(ok_or_error(Reason) :: ok | {error, Reason}).

-type(ok_or_error(Value, Reason) :: {ok, Value} | {error, Reason}).

-type(mfargs() :: {module(), atom(), [term()]}).