Remove quadratic fallback of probe::osc

Author: Morwenn

docs/Measures-of-presortedness.md

@@ -231,16 +231,11 @@ Computes the *Oscillation* measure described by C. Levcopoulos and O. Petersson
 | Complexity  | Memory      | Iterators     |
 | ----------- | ----------- | ------------- |
 | n log n     | n           | Forward       |
-| n²          | 1           | Forward       |
-
-When there isn't enough extra memory available, `probe::osc` falls back to an in-place O(n²) algorithm.
 
 `max_for_size`: (|*X*| * (|*X*| - 2) - 1) / 2 when the values in *X* are strongly oscillating.
 
 **Note:** *Osc* does not respect Mannila's criterion 5: $Osc(\langle 2, 4, 1, 3, 1, 3 \rangle) \not \le |\langle 4, 1, 3, 1, 3 \rangle| + Osc(\langle 4, 1, 3, 1, 3 \rangle)$, though it is possible that it only happens when equivalent elements are involved.
 
-***WARNING:** the O(n²) fallback of `probe::osc` is deprecated since version 1.12.0 and removed in version 2.0.0.*
-
 *Changed in version 1.12.0:* `probe::osc` is now O(n log n) instead of O(n²) but now also requires O(n) memory. The O(n²) is kept for backward compatibility but will be removed in the future.
 
 ### *Rem*

include/cpp-sort/probes/osc.h

@@ -8,10 +8,8 @@
 ////////////////////////////////////////////////////////////
 // Headers
 ////////////////////////////////////////////////////////////
-#include <algorithm>
 #include <functional>
 #include <iterator>
-#include <new>
 #include <numeric>
 #include <utility>
 #include <vector>
@@ -33,44 +31,9 @@ namespace probe
     namespace detail
     {
         template<typename ForwardIterator, typename Compare, typename Projection>
-        auto inplace_osc_algo(ForwardIterator first, ForwardIterator last,
-                              cppsort::detail::difference_type_t<ForwardIterator> size,
-                              Compare compare, Projection projection)
-            -> ::cppsort::detail::difference_type_t<ForwardIterator>
-        {
-            // Deprecated in-place O(n^2) algorithm
-
-            using difference_type = cppsort::detail::difference_type_t<ForwardIterator>;
-            auto&& comp = utility::as_function(compare);
-            auto&& proj = utility::as_function(projection);
-
-            if (size < 2) {
-                return 0;
-            }
-
-            difference_type count = 0;
-            for (auto it = first; it != last; ++it) {
-                auto&& value = proj(*it);
-
-                auto current = first;
-                auto next = std::next(first);
-
-                while (next != last) {
-                    if (comp((std::min)(proj(*current), proj(*next), comp), value) &&
-                        comp(value, (std::max)(proj(*current), proj(*next), comp))) {
-                        ++count;
-                    }
-                    ++current;
-                    ++next;
-                }
-            }
-            return count;
-        }
-
-        template<typename ForwardIterator, typename Compare, typename Projection>
-        auto allocating_osc_algo(ForwardIterator first, ForwardIterator last,
-                                 cppsort::detail::difference_type_t<ForwardIterator> size,
-                                 Compare compare, Projection projection)
+        auto osc_algo(ForwardIterator first, ForwardIterator last,
+                      cppsort::detail::difference_type_t<ForwardIterator> size,
+                      Compare compare, Projection projection)
             -> ::cppsort::detail::difference_type_t<ForwardIterator>
         {
             using difference_type = ::cppsort::detail::difference_type_t<ForwardIterator>;
@@ -155,22 +118,6 @@ namespace probe
             return std::accumulate(cross.begin(), cross.end(), difference_type(0));
         }
 
-        template<typename ForwardIterator, typename Compare, typename Projection>
-        auto osc_algo(ForwardIterator first, ForwardIterator last,
-                      cppsort::detail::difference_type_t<ForwardIterator> size,
-                      Compare compare, Projection projection)
-            -> ::cppsort::detail::difference_type_t<ForwardIterator>
-        {
-            try {
-                return allocating_osc_algo(first, last, size, compare, projection);
-            } catch (std::bad_alloc&) {
-                return inplace_osc_algo(
-                    first, last, size,
-                    std::move(compare), std::move(projection)
-                );
-            }
-        }
-
         struct osc_impl
         {
             template<

tests/probes/every_probe_heap_memory_exhaustion.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2022 Morwenn
+ * Copyright (c) 2020-2025 Morwenn
  * SPDX-License-Identifier: MIT
  */
 #include <algorithm>
@@ -22,7 +22,6 @@
 TEMPLATE_TEST_CASE( "heap exhaustion for random-access probes", "[probe][heap_exhaustion]",
                     decltype(cppsort::probe::dis),
                     decltype(cppsort::probe::mono),
-                    decltype(cppsort::probe::osc),
                     decltype(cppsort::probe::runs) )
 {
     std::vector<int> collection; collection.reserve(491);
@@ -41,7 +40,6 @@ TEMPLATE_TEST_CASE( "heap exhaustion for random-access probes", "[probe][heap_ex
 TEMPLATE_TEST_CASE( "heap exhaustion for bidirectional probes", "[probe][heap_exhaustion]",
                     decltype(cppsort::probe::dis),
                     decltype(cppsort::probe::mono),
-                    decltype(cppsort::probe::osc),
                     decltype(cppsort::probe::runs) )
 {
     std::list<int> collection;
@@ -60,7 +58,6 @@ TEMPLATE_TEST_CASE( "heap exhaustion for bidirectional probes", "[probe][heap_ex
 TEMPLATE_TEST_CASE( "heap exhaustion for forward probes", "[probe][heap_exhaustion]",
                     decltype(cppsort::probe::dis),
                     decltype(cppsort::probe::mono),
-                    decltype(cppsort::probe::osc),
                     decltype(cppsort::probe::runs) )
 {
     std::forward_list<int> collection;