.. _oneapi-mkl-rng-load-state:


oneapi::mkl::rng::load_state
============================


Loads the state of the random number engine from the provided memory buffer or file, then creates new engine object.


.. contents::
    :local:
    :depth: 1

Description
***********

The ``oneapi::mkl::rng::load_state`` function allows you to create a new random number engine object from the binary state of another engine, which was written in a memory buffer or file. You can use different ``sycl::queue`` objects for the new engine.

API
***


Syntax
------

**Load from Memory Interface**

.. code-block:: cpp

   template<typename Engine>
   Engine load_state (const sycl::queue& queue,
     const std::uint8_t* mem);


**Load from File Interface**

.. code-block:: cpp

    template<typename Engine>
    Engine load_state (const sycl::queue& queue,
     const std::string& filename);

Include Files
-------------
- ``oneapi/mkl/rng.hpp``


Input Parameters
----------------

**Load from Memory Interface**

.. list-table::
   :header-rows: 1

   * - Name
     - Type
     - Description
   * - queue
     - ``const sycl::queue& queue``
     - ``sycl::queue`` object, which will be used for the newly-created engine.
   * - mem
     - ``const std::uint8_t*``
     - Memory, where engine\'s state was stored.

**Load from File Interface**

.. list-table::
   :header-rows: 1

   * - Name
     - Type
     - Description
   * - queue
     - ``const sycl::queue& queue``
     - ``sycl::queue`` object, which will be used for the newly-created engine.
   * - filename
     - ``const std::string&``
     - Name of the file where engine\'s state was written.

Output Parameters
-----------------

.. list-table::
   :header-rows: 1

   * - Type
     - Description
   * - Engine
     - New random number engine object, which would be created from the given ``sycl::queue`` and loaded engine\'s state.

The following code illustrates how to store the engine\'s state to the
 ``engine_state.dat`` file and load it back:

Code for Save/Load state functionality
--------------------------------------


.. literalinclude:: /_examples/load_state.cpp
   :language: cpp
   :linenos: