.. _info_namespace_extensions:

oneapi::tbb::info namespace extensions

.. note:: To enable this feature, set the TBB_PREVIEW_TASK_ARENA_CONSTRAINTS_EXTENSION macro to 1.

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

Description

These extensions allow to query information about execution environment.

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

API

Header

.. code:: cpp

#include <oneapi/tbb/info.h>

Syntax

.. code:: cpp

namespace oneapi {
    namespace tbb {
        using core_type_id = /*implementation-defined*/;
        namespace info {
            std::vector<core_type_id> core_types();
            int default_concurrency(task_arena::constraints c);
        }
    }
}

Types

core_type_id - Represents core type identifier.

Functions

.. cpp:function:: std::vector<core_type_id> core_types()

Returns the vector of integral indexes that indicate available core types.
The indexes are sorted from the least performant to the most performant core type.

.. note::
    If error occurs during system topology parsing, returns vector containing single element
    that equals to ``task_arena::automatic``.

.. cpp:function:: int default_concurrency(task_arena::constraints c)

Returns concurrency level for the given constraints.

See also:

• :doc:task_arena::constraints class preview extensions <constraints_extensions>
• info namespace specification <https://spec.oneapi.com/versions/latest/elements/oneTBB/source/info_namespace.html>_