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   SPDX-FileCopyrightText: 1998-2026 Paulo Moura <pmoura@logtalk.org>
   SPDX-License-Identifier: Apache-2.0

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
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.. rst-class:: align-right

**built-in predicate**

.. index:: pair: threaded_ignore/1; Built-in predicate
.. _predicates_threaded_ignore_1:

``threaded_ignore/1``
=====================

Description
-----------

::

   threaded_ignore(Goal)

Proves ``Goal`` asynchronously using a new thread. Only the first goal
solution is found. The argument can be a message-sending goal. This call
always succeeds, independently of the result (success, failure, or
exception), which is simply discarded instead of being sent back to the
message queue of the object containing the call
(:term:`this`).

.. note::

   This predicate requires a :term:`backend Prolog compiler` providing
   compatible multi-threading primitives. The value of the read-only
   :ref:`threads <flag_threads>` flag is set to ``supported`` when that
   is the case.

Meta-predicate template
-----------------------

::

   threaded_ignore(0)

Modes and number of proofs
--------------------------

::

   threaded_ignore(@callable) - one

Errors
------

| ``Goal`` is a variable:
|     ``instantiation_error``
| ``Goal`` is neither a variable nor a callable term:
|     ``type_error(callable, Goal)``

Examples
--------

| Prove ``Goal`` asynchronously in a new thread:
|     ``threaded_ignore(Goal)``
| Prove ``::Message`` asynchronously in a new thread:
|     ``threaded_ignore(::Message)``
| Prove ``Object::Message`` asynchronously in a new thread:
|     ``threaded_ignore(Object::Message)``

.. seealso::

   :ref:`predicates_threaded_call_1_2`,
   :ref:`predicates_threaded_exit_1_2`,
   :ref:`predicates_threaded_once_1_2`,
   :ref:`predicates_threaded_peek_1_2`,
   :ref:`predicates_threaded_1`,
   :ref:`directives_synchronized_1`
