[oneDPL] Clarify the version of the C++ standard for the oneDPL spec (#500)

Author: akukanov

source/elements/oneDPL/source/common.rst

@@ -10,6 +10,6 @@ functionality including parallel algorithms, oneDPL execution policies, etc.
 For the subset of the standard C++ library for kernels, the standard class
 and function names are also aliased in :code:`namespace oneapi::dpl`.
 
-oneDPL uses nested namespaces for the functionality aligned with C++ standard.
+oneDPL uses nested namespaces for the functionality aligned with the C++ standard.
 The names of those namespaces are the same as in :code:`namespace std`. For example,
 oneDPL execution policies are provided in :code:`namespace oneapi::dpl::execution`.

source/elements/oneDPL/source/index.rst

@@ -13,6 +13,10 @@ specified in the `C++ standard`_, with extensions to support data parallelism
 and offloading to devices, and with extensions to simplify its usage for 
 implementing data parallel algorithms.
 
+.. note::
+    Unless specified otherwise, in this document the `C++ standard`_ refers to
+    ISO/IEC 14882:2017 Programming languages - C++, commonly known as C++17. 
+
 The library is comprised of the following components:
 
 - :doc:`Parallel API <parallel_api>`:
@@ -26,12 +30,12 @@ The library is comprised of the following components:
 
 - :doc:`SYCL Kernels API <sycl_kernels_api>`:
 
-  * A subset of the `C++ standard`_ library which can be used with
+  * A subset of the C++ standard library which can be used with
     buffers and data parallel kernels.
 
   * Support of random number generation including engines and distributions.
 
-  * Various utilities in addition to C++ standard functionality.
+  * Various utilities in addition to the C++ standard functionality.
 
 .. toctree::
 

source/elements/oneDPL/source/parallel_api.rst

@@ -5,7 +5,8 @@
 Parallel API
 ------------
 
-oneDPL provides the set of algorithms with execution policies as defined by the `C++ Standard`_.
+oneDPL provides the set of parallel algorithms as defined by the `C++ Standard`_,
+including parallel algorithms added in the 6th edition known as C++20.
 All those algorithms work with *C++ Standard aligned execution policies* and with *DPC++
 execution policies*.
 
@@ -16,7 +17,7 @@ C++ Standard aligned execution policies
 +++++++++++++++++++++++++++++++++++++++
 
 oneDPL has the set of execution policies and related utilities that are semantically aligned
-with the C++ Standard:
+with the `C++ Standard`_, 6th edition (C++20):
 
 .. code:: cpp