P2562R1 constexpr Stable Sorting

Author: jensmaurer

source/algorithms.tex

@@ -2011,9 +2011,9 @@
   }
 
   template<class RandomAccessIterator>
-    void stable_sort(RandomAccessIterator first, RandomAccessIterator last);
+    constexpr void stable_sort(RandomAccessIterator first, RandomAccessIterator last);
   template<class RandomAccessIterator, class Compare>
-    void stable_sort(RandomAccessIterator first, RandomAccessIterator last,
+    constexpr void stable_sort(RandomAccessIterator first, RandomAccessIterator last,
                      Compare comp);
   template<class ExecutionPolicy, class RandomAccessIterator>
     void stable_sort(ExecutionPolicy&& exec,                    // see \ref{algorithms.parallel.overloads}
@@ -2027,10 +2027,10 @@
     template<@\libconcept{random_access_iterator}@ I, @\libconcept{sentinel_for}@<I> S, class Comp = ranges::less,
              class Proj = identity>
       requires @\libconcept{sortable}@<I, Comp, Proj>
-      I stable_sort(I first, S last, Comp comp = {}, Proj proj = {});
+      constexpr I stable_sort(I first, S last, Comp comp = {}, Proj proj = {});
     template<@\libconcept{random_access_range}@ R, class Comp = ranges::less, class Proj = identity>
       requires @\libconcept{sortable}@<iterator_t<R>, Comp, Proj>
-      borrowed_iterator_t<R>
+      constexpr borrowed_iterator_t<R>
         stable_sort(R&& r, Comp comp = {}, Proj proj = {});
   }
 
@@ -2311,9 +2311,9 @@
   }
 
   template<class BidirectionalIterator, class Predicate>
-    BidirectionalIterator stable_partition(BidirectionalIterator first,
-                                           BidirectionalIterator last,
-                                           Predicate pred);
+    constexpr BidirectionalIterator stable_partition(BidirectionalIterator first,
+                                                     BidirectionalIterator last,
+                                                     Predicate pred);
   template<class ExecutionPolicy, class BidirectionalIterator, class Predicate>
     BidirectionalIterator stable_partition(ExecutionPolicy&& exec,  // see \ref{algorithms.parallel.overloads}
                                            BidirectionalIterator first,
@@ -2324,11 +2324,11 @@
     template<@\libconcept{bidirectional_iterator}@ I, @\libconcept{sentinel_for}@<I> S, class Proj = identity,
              @\libconcept{indirect_unary_predicate}@<projected<I, Proj>> Pred>
       requires @\libconcept{permutable}@<I>
-      subrange<I> stable_partition(I first, S last, Pred pred, Proj proj = {});
+      constexpr subrange<I> stable_partition(I first, S last, Pred pred, Proj proj = {});
     template<@\libconcept{bidirectional_range}@ R, class Proj = identity,
              @\libconcept{indirect_unary_predicate}@<projected<iterator_t<R>, Proj>> Pred>
       requires @\libconcept{permutable}@<iterator_t<R>>
-      borrowed_subrange_t<R> stable_partition(R&& r, Pred pred, Proj proj = {});
+      constexpr borrowed_subrange_t<R> stable_partition(R&& r, Pred pred, Proj proj = {});
   }
 
   template<class InputIterator, class OutputIterator1,
@@ -2427,13 +2427,13 @@
   }
 
   template<class BidirectionalIterator>
-    void inplace_merge(BidirectionalIterator first,
-                       BidirectionalIterator middle,
-                       BidirectionalIterator last);
+    constexpr void inplace_merge(BidirectionalIterator first,
+                                 BidirectionalIterator middle,
+                                 BidirectionalIterator last);
   template<class BidirectionalIterator, class Compare>
-    void inplace_merge(BidirectionalIterator first,
-                       BidirectionalIterator middle,
-                       BidirectionalIterator last, Compare comp);
+    constexpr void inplace_merge(BidirectionalIterator first,
+                                 BidirectionalIterator middle,
+                                 BidirectionalIterator last, Compare comp);
   template<class ExecutionPolicy, class BidirectionalIterator>
     void inplace_merge(ExecutionPolicy&& exec,                  // see \ref{algorithms.parallel.overloads}
                        BidirectionalIterator first,
@@ -2449,10 +2449,10 @@
     template<@\libconcept{bidirectional_iterator}@ I, @\libconcept{sentinel_for}@<I> S, class Comp = ranges::less,
              class Proj = identity>
       requires @\libconcept{sortable}@<I, Comp, Proj>
-      I inplace_merge(I first, I middle, S last, Comp comp = {}, Proj proj = {});
+      constexpr I inplace_merge(I first, I middle, S last, Comp comp = {}, Proj proj = {});
     template<@\libconcept{bidirectional_range}@ R, class Comp = ranges::less, class Proj = identity>
       requires @\libconcept{sortable}@<iterator_t<R>, Comp, Proj>
-      borrowed_iterator_t<R>
+      constexpr borrowed_iterator_t<R>
         inplace_merge(R&& r, iterator_t<R> middle, Comp comp = {},
                       Proj proj = {});
   }

source/support.tex

@@ -592,7 +592,7 @@
 #define @\defnlibxname{cpp_lib_common_reference_wrapper}@          202302L // also in \libheader{functional}
 #define @\defnlibxname{cpp_lib_complex_udls}@                      201309L // also in \libheader{complex}
 #define @\defnlibxname{cpp_lib_concepts}@                          202207L // also in \libheader{concepts}, \libheader{compare}
-#define @\defnlibxname{cpp_lib_constexpr_algorithms}@              201806L // also in \libheader{algorithm}, \libheader{utility}
+#define @\defnlibxname{cpp_lib_constexpr_algorithms}@              202306L // also in \libheader{algorithm}, \libheader{utility}
 #define @\defnlibxname{cpp_lib_constexpr_bitset}@                  202207L // also in \libheader{bitset}
 #define @\defnlibxname{cpp_lib_constexpr_charconv}@                202207L // also in \libheader{charconv}
 #define @\defnlibxname{cpp_lib_constexpr_cmath}@                   202202L // also in \libheader{cmath}, \libheader{cstdlib}