Fix QtConcurrent::blockingMapped to work with non-template sequences

The code for deducing the type of output sequence was assuming that the
input sequence is always a template class and was trying to use the
corresponding container type for the output sequence. Fixed the
deduction code, to assume that the output sequence has the same type as
the input sequence, when it's not a template class. Also added tests to
verify that all QtConcurrent functions support non-template input
sequences.

Fixes: QTBUG-30617
Change-Id: I486fe99f3207cfff5dcceb3712cc7de863067edb
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
(cherry picked from commit 28e194d3b25f5fc6e17cce8dddba7f7e16002c43)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

4 files changed, 202 insertions, 1 deletions

diff --git a/src/concurrent/qtconcurrentfunctionwrappers.h b/src/concurrent/qtconcurrentfunctionwrappers.h
index 194d020fb2..a00c1c6edc 100644
--- a/src/concurrent/qtconcurrentfunctionwrappers.h
+++ b/src/concurrent/qtconcurrentfunctionwrappers.h
@@ -146,7 +146,13 @@ struct ReduceResultType<T(C::*)(U) noexcept>
 // -- MapSequenceResultType
 
 template <class InputSequence, class MapFunctor>
-struct MapSequenceResultType;
+struct MapSequenceResultType
+{
+    static_assert(std::is_same_v<typename InputSequence::value_type,
+                                 QtPrivate::MapResultType<InputSequence, MapFunctor>>,
+                  "Couldn't deduce the output sequence type, you must specify it explicitly.");
+    typedef InputSequence ResultType;
+};
 
 template <class MapFunctor>
 struct MapSequenceResultType<QStringList, MapFunctor>
diff --git a/tests/auto/concurrent/qtconcurrentfilter/tst_qtconcurrentfilter.cpp b/tests/auto/concurrent/qtconcurrentfilter/tst_qtconcurrentfilter.cpp
index 6c27884977..a6c575fd4d 100644
--- a/tests/auto/concurrent/qtconcurrentfilter/tst_qtconcurrentfilter.cpp
+++ b/tests/auto/concurrent/qtconcurrentfilter/tst_qtconcurrentfilter.cpp
@@ -102,6 +102,19 @@ void tst_QtConcurrentFilter::filter()
     CHECK_FAIL("member");
     testFilter(intList, intListEven, lambdaIsEven);
     CHECK_FAIL("lambda");
+
+    // non-template sequences
+    {
+
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        QtConcurrent::filter(list, keepEvenNumbers).waitForFinished();
+        QCOMPARE(list, NonTemplateSequence({ 2, 4 }));
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        QtConcurrent::blockingFilter(list, keepEvenNumbers);
+        QCOMPARE(list, NonTemplateSequence({ 2, 4 }));
+    }
 }
 
 static QSemaphore semaphore(1);
@@ -179,6 +192,19 @@ void tst_QtConcurrentFilter::filterThreadPool()
     CHECK_FAIL("function");
     testFilterThreadPool(&pool, intList, intListEven, lambdaIsOdd);
     CHECK_FAIL("lambda");
+
+    // non-template sequences
+    {
+
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        QtConcurrent::filter(list, keepEvenIntegers).waitForFinished();
+        QCOMPARE(list, NonTemplateSequence({ 2, 4 }));
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        QtConcurrent::blockingFilter(list, keepEvenIntegers);
+        QCOMPARE(list, NonTemplateSequence({ 2, 4 }));
+    }
 }
 
 void tst_QtConcurrentFilter::filterWithMoveOnlyCallable()
@@ -254,6 +280,18 @@ void tst_QtConcurrentFilter::filtered()
     testFiltered(intList, intListEven, lambdaIsEven);
     CHECK_FAIL("lambda");
 
+    // non-template sequences
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto future = QtConcurrent::filtered(list, keepEvenIntegers);
+        QCOMPARE(future.results(), QList({ 2, 4 }));
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto result = QtConcurrent::blockingFiltered(list, keepEvenIntegers);
+        QCOMPARE(result, NonTemplateSequence({ 2, 4 }));
+    }
+
     {
         // rvalue sequences
         auto future = QtConcurrent::filtered(std::vector { 1, 2, 3, 4 }, keepEvenIntegers);
@@ -329,6 +367,18 @@ void tst_QtConcurrentFilter::filteredThreadPool()
     testFilteredThreadPool(&pool, intList, intListEven, lambdaIsOdd);
     CHECK_FAIL("lambda");
 
+    // non-template sequences
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto future = QtConcurrent::filtered(&pool, list, keepEvenIntegers);
+        QCOMPARE(future.results(), QList({ 2, 4 }));
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto result = QtConcurrent::blockingFiltered(&pool, list, keepEvenIntegers);
+        QCOMPARE(result, NonTemplateSequence({ 2, 4 }));
+    }
+
     {
         // rvalue sequences
         auto future = QtConcurrent::filtered(&pool, std::vector { 1, 2, 3, 4 }, keepEvenIntegers);
@@ -537,6 +587,18 @@ void tst_QtConcurrentFilter::filteredReduced()
     testFilteredReduced(intList, intSum, lambdaIsEven, lambdaIntSumReduce);
     CHECK_FAIL("lambda-lambda");
 
+    // non-template sequences
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto future = QtConcurrent::filteredReduced(list, keepEvenIntegers, intSumReduce);
+        QCOMPARE(future.result(), intSum);
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto result = QtConcurrent::blockingFilteredReduced(list, keepEvenIntegers, intSumReduce);
+        QCOMPARE(result, intSum);
+    }
+
     {
         // rvalue sequences
         auto future = QtConcurrent::filteredReduced(std::vector { 1, 2, 3, 4 }, keepEvenIntegers,
@@ -636,6 +698,19 @@ void tst_QtConcurrentFilter::filteredReducedThreadPool()
     testFilteredReducedThreadPool(&pool, intList, intSum, lambdaIsOdd, lambdaSumReduce);
     CHECK_FAIL("lambda-lambda");
 
+    // non-template sequences
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto future = QtConcurrent::filteredReduced(&pool, list, keepOddIntegers, intSumReduce);
+        QCOMPARE(future.result(), intSum);
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto result =
+                QtConcurrent::blockingFilteredReduced(&pool, list, keepOddIntegers, intSumReduce);
+        QCOMPARE(result, intSum);
+    }
+
     {
         // rvalue sequences
         auto future = QtConcurrent::filteredReduced(&pool, std::vector { 1, 2, 3, 4 },
@@ -910,6 +985,20 @@ void tst_QtConcurrentFilter::filteredReducedInitialValue()
                                     lambdaIntSumReduce, intInitial);
     CHECK_FAIL("lambda-lambda");
 
+    // non-template sequences
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto future =
+                QtConcurrent::filteredReduced(list, keepEvenIntegers, intSumReduce, intInitial);
+        QCOMPARE(future.result(), intSum);
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto result = QtConcurrent::blockingFilteredReduced(list, keepEvenIntegers, intSumReduce,
+                                                            intInitial);
+        QCOMPARE(result, intSum);
+    }
+
     {
         // rvalue sequences
         auto future = QtConcurrent::filteredReduced(std::vector { 1, 2, 3, 4 }, keepEvenIntegers,
@@ -1021,6 +1110,20 @@ void tst_QtConcurrentFilter::filteredReducedInitialValueThreadPool()
                                               lambdaSumReduce, intInitial);
     CHECK_FAIL("lambda-lambda");
 
+    // non-template sequences
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto future =
+                QtConcurrent::filteredReduced(list, keepOddIntegers, intSumReduce, intInitial);
+        QCOMPARE(future.result(), intSum);
+    }
+    {
+        NonTemplateSequence list({ 1, 2, 3, 4 });
+        auto result = QtConcurrent::blockingFilteredReduced(list, keepOddIntegers, intSumReduce,
+                                                            intInitial);
+        QCOMPARE(result, intSum);
+    }
+
     {
         // rvalue sequences
         auto future = QtConcurrent::filteredReduced(&pool, std::vector { 1, 2, 3, 4 },
diff --git a/tests/auto/concurrent/qtconcurrentmap/tst_qtconcurrentmap.cpp b/tests/auto/concurrent/qtconcurrentmap/tst_qtconcurrentmap.cpp
index 5bcf90c0d6..8fdfd0ccc2 100644
--- a/tests/auto/concurrent/qtconcurrentmap/tst_qtconcurrentmap.cpp
+++ b/tests/auto/concurrent/qtconcurrentmap/tst_qtconcurrentmap.cpp
@@ -201,6 +201,13 @@ void tst_QtConcurrentMap::map()
         QCOMPARE(moveOnlyVector, MoveOnlyVector<int>({ 2, 4, 6 }));
     }
 
+    // non-template sequences
+    {
+        NonTemplateSequence list { 1, 2, 3 };
+        QtConcurrent::map(list, multiplyBy2InPlace).waitForFinished();
+        QCOMPARE(list, NonTemplateSequence({ 2, 4, 6 }));
+    }
+
 #if 0
     // not allowed: map() with immutable sequences makes no sense
     {
@@ -331,6 +338,13 @@ void tst_QtConcurrentMap::blockingMap()
         QCOMPARE(list, QList<int>() << 1 << 2 << 3);
     }
 
+    // non-template sequences
+    {
+        NonTemplateSequence list { 1, 2, 3 };
+        QtConcurrent::blockingMap(list, multiplyBy2InPlace);
+        QCOMPARE(list, NonTemplateSequence({ 2, 4, 6 }));
+    }
+
 #if 0
     // not allowed: map() with immutable sequences makes no sense
     {
@@ -564,6 +578,17 @@ void tst_QtConcurrentMap::mapped()
 #endif
 
     {
+        // non-template sequences
+        NonTemplateSequence list { 1, 2, 3 };
+
+        auto future = QtConcurrent::mapped(list, multiplyBy2);
+        QCOMPARE(future.results(), QList({ 2, 4, 6 }));
+
+        auto result = QtConcurrent::blockingMapped(list, multiplyBy2);
+        QCOMPARE(result, NonTemplateSequence({ 2, 4, 6 }));
+    }
+
+    {
         // rvalue sequences
         auto future = QtConcurrent::mapped(std::vector { 1, 2, 3 }, multiplyBy2);
         QCOMPARE(future.results(), QList<int>({ 2, 4, 6 }));
@@ -667,6 +692,17 @@ void tst_QtConcurrentMap::mappedThreadPool()
     CHECK_FAIL("lambda");
 
     {
+        // non-template sequences
+        NonTemplateSequence list { 1, 2, 3 };
+
+        auto future = QtConcurrent::mapped(&pool, list, multiplyBy2);
+        QCOMPARE(future.results(), QList({ 2, 4, 6 }));
+
+        auto result = QtConcurrent::blockingMapped(&pool, list, multiplyBy2);
+        QCOMPARE(result, NonTemplateSequence({ 2, 4, 6 }));
+    }
+
+    {
         // rvalue sequences
         auto future = QtConcurrent::mapped(&pool, std::vector { 1, 2, 3 }, multiplyBy2);
         QCOMPARE(future.results(), QList<int>({ 2, 4, 6 }));
@@ -858,6 +894,17 @@ void tst_QtConcurrentMap::mappedReduced()
     CHECK_FAIL("lambda-lambda");
 
     {
+        // non-template sequences
+        NonTemplateSequence list { 1, 2, 3 };
+
+        auto future = QtConcurrent::mappedReduced(list, multiplyBy2, intSumReduce);
+        QCOMPARE(future.result(), 12);
+
+        auto result = QtConcurrent::blockingMappedReduced(list, multiplyBy2, intSumReduce);
+        QCOMPARE(result, 12);
+    }
+
+    {
         // rvalue sequences
         auto future = QtConcurrent::mappedReduced(std::vector { 1, 2, 3 }, intSquare, intSumReduce);
         QCOMPARE(future.result(), sumOfSquares);
@@ -967,6 +1014,17 @@ void tst_QtConcurrentMap::mappedReducedThreadPool()
     CHECK_FAIL("lambda-lambda");
 
     {
+        // non-template sequences
+        NonTemplateSequence list { 1, 2, 3 };
+
+        auto future = QtConcurrent::mappedReduced(&pool, list, multiplyBy2, intSumReduce);
+        QCOMPARE(future.result(), 12);
+
+        auto result = QtConcurrent::blockingMappedReduced(&pool, list, multiplyBy2, intSumReduce);
+        QCOMPARE(result, 12);
+    }
+
+    {
         // rvalue sequences
         auto future =
                 QtConcurrent::mappedReduced(&pool, std::vector { 1, 2, 3 }, intCube, intSumReduce);
@@ -1204,6 +1262,18 @@ void tst_QtConcurrentMap::mappedReducedInitialValue()
     CHECK_FAIL("lambda-lambda");
 
     {
+        // non-template sequences
+        NonTemplateSequence list { 1, 2, 3 };
+
+        auto future = QtConcurrent::mappedReduced(list, multiplyBy2, intSumReduce, intInitial);
+        QCOMPARE(future.result(), intInitial + 12);
+
+        auto result =
+                QtConcurrent::blockingMappedReduced(list, multiplyBy2, intSumReduce, intInitial);
+        QCOMPARE(result, intInitial + 12);
+    }
+
+    {
         // rvalue sequences
         auto future = QtConcurrent::mappedReduced(std::vector { 1, 2, 3 }, intSquare, intSumReduce,
                                                   intInitial);
@@ -1312,6 +1382,19 @@ void tst_QtConcurrentMap::mappedReducedInitialValueThreadPool()
     CHECK_FAIL("lambda-lambda");
 
     {
+        // non-template sequences
+        NonTemplateSequence list { 1, 2, 3 };
+
+        auto future =
+                QtConcurrent::mappedReduced(&pool, list, multiplyBy2, intSumReduce, intInitial);
+        QCOMPARE(future.result(), intInitial + 12);
+
+        auto result = QtConcurrent::blockingMappedReduced(&pool, list, multiplyBy2, intSumReduce,
+                                                          intInitial);
+        QCOMPARE(result, intInitial + 12);
+    }
+
+    {
         // rvalue sequences
         auto future = QtConcurrent::mappedReduced(&pool, std::vector { 1, 2, 3 }, intCube,
                                                   intSumReduce, intInitial);
diff --git a/tests/auto/concurrent/testhelper_functions.h b/tests/auto/concurrent/testhelper_functions.h
index e890053e5c..a34e0f4ce9 100644
--- a/tests/auto/concurrent/testhelper_functions.h
+++ b/tests/auto/concurrent/testhelper_functions.h
@@ -28,6 +28,8 @@
 #ifndef FUNCTIONS_H
 #define FUNCTIONS_H
 
+#include <QList>
+
 #include <vector>
 
 bool keepEvenIntegers(const int &x)
@@ -196,4 +198,11 @@ private:
     std::vector<T> data;
 };
 
+struct NonTemplateSequence : public QList<int>
+{
+    NonTemplateSequence() = default;
+
+    NonTemplateSequence(std::initializer_list<int> args) : QList(args) { }
+};
+
 #endif