QDuplicateTracker: bring back appendTo() &&

This reverts commit c19695ab953c979f15bbc72c4f4a453e9a114cf6.

Just because QSet has limited API doesn't mean we can't provide this
in an efficient way for std::unordered_set :P

Added tests.

Change-Id: I4f8f0e60c810acdc666cf34f929845227ed87f3b
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
(cherry picked from commit 8c49ae522d184deb5a9118ba2368629709ff6e85)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 37 insertions, 7 deletions

diff --git a/tests/auto/corelib/tools/qduplicatetracker/tst_qduplicatetracker.cpp b/tests/auto/corelib/tools/qduplicatetracker/tst_qduplicatetracker.cpp
index f4f038ca94..41a1e791a7 100644
--- a/tests/auto/corelib/tools/qduplicatetracker/tst_qduplicatetracker.cpp
+++ b/tests/auto/corelib/tools/qduplicatetracker/tst_qduplicatetracker.cpp
@@ -94,9 +94,15 @@ void tst_QDuplicateTracker::appendTo()
 
     QVERIFY(!tracker.hasSeen(2));
     QList<int> c;
-    tracker.appendTo(c);
+    std::move(tracker).appendTo(c);
     std::sort(c.begin(), c.end());
     QCOMPARE(c, QList<int>({ 0, 1, 2 }));
+    if (QDuplicateTracker<int, 2>::uses_pmr) {
+        // the following is only true if we use the std container
+        QVERIFY(!tracker.hasSeen(0));
+        QVERIFY(!tracker.hasSeen(1));
+        QVERIFY(!tracker.hasSeen(2));
+    }
 }
 
 struct ConstructionCounted
@@ -173,12 +179,36 @@ void tst_QDuplicateTracker::appendTo_special()
     QVERIFY(!tracker.hasSeen(1));
     QVERIFY(!tracker.hasSeen(2));
     QVERIFY(!tracker.hasSeen(3));
-    QList<ConstructionCounted> a;
-    a.reserve(3);
-    tracker.appendTo(a);
-    for (const auto &counter : a) {
-        QCOMPARE(counter.moves, 1);
-        QCOMPARE(counter.copies, 1);
+
+    QVERIFY(tracker.hasSeen(1));
+    QVERIFY(tracker.hasSeen(2));
+    QVERIFY(tracker.hasSeen(3));
+    {
+        QList<ConstructionCounted> a;
+        a.reserve(3);
+        tracker.appendTo(a);
+        for (const auto &counter : a) {
+            QCOMPARE(counter.moves, 1);
+            QCOMPARE(counter.copies, 1);
+        }
+    }
+    QVERIFY(tracker.hasSeen(1));
+    QVERIFY(tracker.hasSeen(2));
+    QVERIFY(tracker.hasSeen(3));
+    {
+        QList<ConstructionCounted> a;
+        a.reserve(3);
+        std::move(tracker).appendTo(a);
+        if (QDuplicateTracker<ConstructionCounted>::uses_pmr) {
+            // the following is only true if we use the std container
+            for (const auto &counter : a) {
+                QCOMPARE(counter.moves, 2);
+                QCOMPARE(counter.copies, 0);
+            }
+            QVERIFY(!tracker.hasSeen(1));
+            QVERIFY(!tracker.hasSeen(2));
+            QVERIFY(!tracker.hasSeen(3));
+        }
     }
 }