Keep only nothrow-random-access-range and its semantic requirements

Author: dmitriy-sobolev

source/elements/oneDPL/source/parallel_api/parallel_range_api.rst

@@ -47,35 +47,30 @@ of parallel range algorithms.
 .. code:: cpp
 
    // C++20 analogue of std::projected_value_t; exposition only
-   template<typename I, typename Proj>
+   template <typename I, typename Proj>
    using /*projected-value-type*/ = std::remove_cvref_t<std::invoke_result_t<Proj&, std::iter_value_t<I>&>>;
 
-  // Extension of C++20 exposition-only special memory concepts as defined in [special.mem.concepts]
-  template<typename S, typename I>
-  concept no-throw-sized-sentinel-for = // exposition only
-    no-throw-sentinel-for<S, I> &&
-    std::sized_sentinel_for<S, I>;
-
-  template<typename I>
-  concept no-throw-bidirectional-iterator = // exposition only
-    no-throw-forward-iterator<I> &&
-    std::bidirectional_iterator<I>;
-
-  template<typename I>
-  concept no-throw-random-access-iterator = // exposition only
-    no-throw-bidirectional-iterator<I> &&
-    std::random_access_iterator<I> &&
-    no-throw-sized-sentinel-for<I, I>;
-
-  template<typename R>
-  concept no-throw-bidirectional-range = // exposition only
-    no-throw-forward-range<R> &&
-    no-throw-bidirectional-iterator<std::ranges::iterator_t<R>>;
-
-  template<typename R>
-  concept no-throw-random-access-range = // exposition only
-    no-throw-bidirectional-range<R> &&
-    no-throw-random-access-iterator<std::ranges::iterator_t<R>>;
+  // C++20 analogue of nothrow-random-access-range proposed for C++26 in P3179R9; exposition only
+  template <typename R>
+  concept nothrow-random-access-range =
+    std::ranges::random_access_range<R> &&
+    std::is_lvalue_reference_v<std::iter_reference_t<I>> &&
+    std::same_as<std::remove_cvref_t<std::iter_reference_t<I>>, std::iter_value_t<I>> &&
+    std::sized_sentinel_for<std::ranges::sentinel_t<R>, std::ranges::iterator_t<R>>;
+
+Semantic Requirements
+~~~~~~~~~~~~~~~~~~~~
+
+A type ``R`` models ``nothrow-random-access-range`` if no exceptions are thrown from:
+
+- increment, decrement, copy construction, move construction, copy assignment, move assignment,
+  comparisons or indirection through valid iterators of type ``std::ranges::iterator_t<R>``;
+- ``-`` operator, copy construction, move construction, copy assignment, move assignment,
+  or comparisons between valid values of type ``std::ranges::iterator_t<R>`` and ``std::ranges::sentinel_t<R>``;
+- ``-``, ``+``, ``-=``, ``+=``, ``[]`` operators on valid values of type
+  ``std::ranges::iterator_t<R>`` and ``std::iter_difference_t<std::ranges::iterator_t<R>>``;
+- calls to ``std::ranges::begin()``, ``std::ranges::end()`` and ``std::ranges::size()``
+  on an object of type ``R``.
 
 Whole Sequence Operations
 +++++++++++++++++++++++++