%% %CopyrightBegin%
%%
%% SPDX-License-Identifier: Apache-2.0
%%
%% Copyright Ericsson AB 2021-2025. All Rights Reserved.
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[;1m  alias(Opts)[0m

[;;4mSince[0m:
  OTP 24.0

  Create an alias which can be used when sending messages to the
  process that created the alias. When the alias has been
  deactivated, messages sent using the alias will be dropped. An
  alias can be deactivated using [;;4munalias/1[0m.

  Currently available options for [;;4malias/1[0m:

   • [;;4mexplicit_unalias[0m - The alias can only be deactivated via a
     call to [;;4munalias/1[0m. This is also the default behaviour if
     no options are passed or if [;;4malias/0[0m is called.

   • [;;4mreply[0m - The alias will be automatically deactivated when a
     reply message sent via the alias is received. The alias can
     also still be deactivated via a call to [;;4munalias/1[0m.

   • [;;4mpriority[0m - Since OTP @OTP-19198@

     The alias can be used for sending priority messages to the
     process that created this alias. An alias created with this
     option is also known as a priority process alias or
     shorter priority alias.

  [;;4mWarning[0m

       You very seldom need to resort to using priority
       messages and you may cause issues instead of solving
       issues if not used with care.

     For more information see, the Enabling Priority Message
     Reception section of the Erlang Reference Manual.

  Example:

    server() ->
        receive
            {request, AliasReqId, Request} ->
                Result = perform_request(Request),
                AliasReqId ! {reply, AliasReqId, Result}
        end,
        server().
    
    client(ServerPid, Request) ->
        AliasReqId = alias([reply]),
        ServerPid ! {request, AliasReqId, Request},
        %% Alias will be automatically deactivated if we receive a reply
        %% since we used the 'reply' option...
        receive
            {reply, AliasReqId, Result} -> Result
        after 5000 ->
                unalias(AliasReqId),
                %% Flush message queue in case the reply arrived
                %% just before the alias was deactivated...
                receive {reply, AliasReqId, Result} -> Result
                after 0 -> exit(timeout)
                end
        end.

  Note that both the server and the client in this example must be
  executing on at least OTP 24 systems in order for this to work.

  For more information on process aliases see the Process Aliases
  section of the Erlang Reference Manual.
