Cleanup indirect_adapter algorithms

Author: Morwenn

include/cpp-sort/adapters/indirect_adapter.h

@@ -98,10 +98,9 @@ namespace cppsort
                     // Find the element to put in current's place
                     auto current = start;
                     auto next_pos = current - first;
-                    auto next = iterators[next_pos];
                     // We replace all "sorted" iterators with last to make it
                     // possible to find unsorted iterators between cycles
-                    iterators[next_pos] = last;
+                    auto next = std::exchange(iterators[next_pos], last);
 
                     // Process the current cycle
                     if (next != current) {
@@ -110,8 +109,7 @@ namespace cppsort
                             *current = iter_move(next);
                             current = next;
                             auto next_pos = next - first;
-                            next = iterators[next_pos];
-                            iterators[next_pos] = last;
+                            next = std::exchange(iterators[next_pos], last);
                         }
                         *current = std::move(tmp);
                     }

include/cpp-sort/detail/indiesort.h

@@ -100,22 +100,22 @@ namespace detail
 
             // Sort the actual elements via the tuple array:
             index = 0;
-            for (auto current_tuple = storage.begin(); current_tuple != storage.end(); ++current_tuple, ++index) {
-                if (current_tuple->original_index != index) {
-                    auto end_value = iter_move(current_tuple->original_location);
+            for (auto const& current_tuple : storage) {
+                if (current_tuple.original_index != index) {
+                    auto end_value = iter_move(current_tuple.original_location);
 
                     auto destination_index = index;
-                    auto source_index = current_tuple->original_index;
+                    auto source_index = current_tuple.original_index;
 
                     do {
                         *(storage[destination_index].original_location) = iter_move(storage[source_index].original_location);
 
                         destination_index = source_index;
-                        source_index = storage[destination_index].original_index;
-                        storage[destination_index].original_index = destination_index;
+                        source_index = std::exchange(storage[destination_index].original_index, destination_index);
                     } while (source_index != index);
                     *(storage[destination_index].original_location) = std::move(end_value);
                 }
+                ++index;
             }
 
 #ifdef __cpp_lib_uncaught_exceptions