.. _oneapi-mkl-rng-save-state:

oneapi::mkl::rng::save_state
============================


Writes state of the random number engine to the file or memory buffer.


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

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

The ``oneapi::mkl::rng::save_state`` function allows you to store the state of the random number engine in the binary format in a file or memory buffer.

API
***


Syntax
------

**Save to Memory Interface**

.. code-block:: cpp

   template<typename Engine>
   void save_state (Engine& engine,
     std::uint8_t* mem);


**Save to File Interface**

.. code-block:: cpp

    template<typename Engine>
    void save_state (Engine& engine,
     const std::string& filename);

Include Files
-------------

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


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

**Save to Memory Interface**

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

   * - Name
     - Type
     - Description
   * - engine
     - ``Engine&``
     -  Object of engine class, which state would be saved.
   * - mem
     - ``std::uint8_t*``
     -  Memory, which you allocate to store the engine's state. To check the size of memory in bytes needed for the particular engine, use the ``oneapi::mkl::rng::get_state_size`` function.

**Save to File Interface**

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

   * - Name
     - Type
     - Description
   * - engine
     - ``Engine&``
     - Object of engine class, which state would be saved.
   * - filename
     - ``const std::string&``
     - Name of the file where the engine's state would be written.