.. SPDX-FileCopyrightText: 2019-2021 Intel Corporation
..
.. SPDX-License-Identifier: CC-BY-4.0

==============
broadcast_node
==============
**[flow_graph.broadcast_node]**

A node that broadcasts incoming messages to all of its successors.

.. code:: cpp

    // Defined in header <oneapi/tbb/flow_graph.h>
    
    namespace oneapi {
    namespace tbb {
    namespace flow {

        template< typename T >
        class broadcast_node :
        public graph_node, public receiver<T>, public sender<T> {
        public:
            explicit broadcast_node( graph &g );
            broadcast_node( const broadcast_node &src );

            // Preview feature: Helper Functions for Expressing Graphs
            explicit broadcast_node(decltype(follows(...)));
            explicit broadcast_node(decltype(precedes(...)));

            bool try_put( const T &v );
            bool try_get( T &v );

            // Preview feature: Waiting for Single Message
            bool try_put_and_wait(const T& v);
        };

    } // namespace flow
    } // namespace tbb
    } //namespace oneapi

``broadcast_node`` is a ``graph_node``, ``receiver<T>``, and ``sender<T>``.

``broadcast_node`` has a `discarding` and `broadcast-push` :doc:`properties <forwarding_and_buffering>`.

All messages are forwarded immediately to all successors.

Member functions
----------------

.. cpp:function:: explicit broadcast_node( graph &g )

  Constructs an object of type ``broadcast_node`` that belongs to the
  graph ``g``.

.. cpp:function:: broadcast_node( const broadcast_node &src )

  Constructs an object of type ``broadcast_node`` that belongs to the
  same graph ``g`` as ``src``. The list of predecessors and the list of
  successors are not copied.

.. cpp:function:: bool try_put( const input_type &v )

  Broadcasts ``v`` to all successors.

  **Returns**: always returns ``true``, even if it was unable to
  successfully forward the message to any of its successors.

.. cpp:function:: bool try_get( output_type &v )

  **Returns**: ``false``.

Preview Features
----------------

The following :ref:`preview features<preview_features>` extend the ``broadcast_node`` API:

* :ref:`Helper Functions for Expressing Graphs<helpers_for_expressing_graphs>` - allows ``broadcast_node``
  to be constructed as a successor or a predecessor of the set of nodes.
* :ref:`Waiting for Single Message in Flow Graph<try_put_and_wait>` - allows to put messages
  to ``broadcast_node`` and wait for all related work to complete.