Eliminate the extra copy in QtConcurrent's blocking methods

Use QFuture::takeResult() instead of QFuture::result() for returning the
resulting sequence from the blocking methods of QtConcurrent.

Change-Id: I0b623ee1ad8bda6789f329dcd63a46acda924539
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

2 files changed, 32 insertions, 32 deletions

diff --git a/src/concurrent/qtconcurrentfilter.h b/src/concurrent/qtconcurrentfilter.h
index a85cbc0224..8a17487466 100644
--- a/src/concurrent/qtconcurrentfilter.h
+++ b/src/concurrent/qtconcurrentfilter.h
@@ -365,7 +365,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             pool, std::forward<Sequence>(sequence), keep, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor>
@@ -377,7 +377,7 @@ ResultType blockingFilteredReduced(Sequence &&sequence,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             QThreadPool::globalInstance(), std::forward<Sequence>(sequence), keep, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
@@ -394,7 +394,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             pool, std::forward<Sequence>(sequence), keep, reduce,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor,
@@ -410,7 +410,7 @@ ResultType blockingFilteredReduced(Sequence &&sequence,
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             QThreadPool::globalInstance(), std::forward<Sequence>(sequence), keep, reduce,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 #ifndef Q_CLANG_QDOC
@@ -425,7 +425,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             pool, std::forward<Sequence>(sequence), keep, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Sequence, typename KeepFunctor, typename ReduceFunctor,
@@ -438,7 +438,7 @@ ResultType blockingFilteredReduced(Sequence &&sequence,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             QThreadPool::globalInstance(), std::forward<Sequence>(sequence), keep, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Sequence, typename KeepFunctor, typename ReduceFunctor,
@@ -456,7 +456,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             pool, std::forward<Sequence>(sequence), keep, reduce,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Sequence, typename KeepFunctor, typename ReduceFunctor,
@@ -473,7 +473,7 @@ ResultType blockingFilteredReduced(Sequence &&sequence,
     QFuture<ResultType> future = startFilteredReduced<ResultType>(
             QThreadPool::globalInstance(), std::forward<Sequence>(sequence), keep, reduce,
             ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 #endif
 
@@ -489,7 +489,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(pool, begin, end, keep,
                                  reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor>
@@ -502,7 +502,7 @@ ResultType blockingFilteredReduced(Iterator begin,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(QThreadPool::globalInstance(),
                                  begin, end, keep, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
@@ -519,7 +519,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(pool, begin, end, keep, reduce,
         ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor,
@@ -535,7 +535,7 @@ ResultType blockingFilteredReduced(Iterator begin,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(QThreadPool::globalInstance(),
         begin, end, keep, reduce, ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 #ifndef Q_CLANG_QDOC
@@ -551,7 +551,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(pool, begin, end, keep,
                                                                   reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename KeepFunctor, typename ReduceFunctor,
@@ -565,7 +565,7 @@ ResultType blockingFilteredReduced(Iterator begin,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(QThreadPool::globalInstance(),
                                  begin, end, keep, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename KeepFunctor, typename ReduceFunctor,
@@ -582,7 +582,7 @@ ResultType blockingFilteredReduced(QThreadPool *pool,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(pool, begin, end, keep, reduce,
         ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename KeepFunctor, typename ReduceFunctor,
@@ -599,7 +599,7 @@ ResultType blockingFilteredReduced(Iterator begin,
 {
     QFuture<ResultType> future = startFilteredReduced<ResultType>(QThreadPool::globalInstance(),
         begin, end, keep, reduce, ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 #endif
 
diff --git a/src/concurrent/qtconcurrentmap.h b/src/concurrent/qtconcurrentmap.h
index e7c188fb8c..2b475dced1 100644
--- a/src/concurrent/qtconcurrentmap.h
+++ b/src/concurrent/qtconcurrentmap.h
@@ -399,7 +399,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (pool, std::forward<Sequence>(sequence), map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor>
@@ -412,7 +412,7 @@ ResultType blockingMappedReduced(Sequence &&sequence,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), std::forward<Sequence>(sequence), map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
@@ -430,7 +430,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
             <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
             (pool, std::forward<Sequence>(sequence), map, reduce,
              ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor,
@@ -447,7 +447,7 @@ ResultType blockingMappedReduced(Sequence &&sequence,
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), std::forward<Sequence>(sequence), map, reduce,
          ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename MapFunctor, typename ReduceFunctor, typename Sequence,
@@ -462,7 +462,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (pool, std::forward<Sequence>(sequence), map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename MapFunctor, typename ReduceFunctor, typename Sequence,
@@ -476,7 +476,7 @@ ResultType blockingMappedReduced(Sequence &&sequence,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), std::forward<Sequence>(sequence), map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename MapFunctor, typename ReduceFunctor, typename Sequence,
@@ -495,7 +495,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (pool, std::forward<Sequence>(sequence), map, reduce,
          ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename MapFunctor, typename ReduceFunctor, typename Sequence,
@@ -513,7 +513,7 @@ ResultType blockingMappedReduced(Sequence &&sequence,
         <QtPrivate::MapResultType<Sequence, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), std::forward<Sequence>(sequence), map, reduce,
          ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 // blockingMappedReduced() for iterator ranges
@@ -529,7 +529,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (pool, begin, end, map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor>
@@ -543,7 +543,7 @@ ResultType blockingMappedReduced(Iterator begin,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), begin, end, map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
@@ -562,7 +562,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (pool, begin, end, map, reduce, ResultType(std::forward<InitialValueType>(initialValue)),
          options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor,
@@ -580,7 +580,7 @@ ResultType blockingMappedReduced(Iterator begin,
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), begin, end, map, reduce,
          ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
@@ -596,7 +596,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (pool, begin, end, map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
@@ -611,7 +611,7 @@ ResultType blockingMappedReduced(Iterator begin,
     QFuture<ResultType> future = QtConcurrent::startMappedReduced
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), begin, end, map, reduce, options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
@@ -631,7 +631,7 @@ ResultType blockingMappedReduced(QThreadPool *pool,
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (pool, begin, end, map, reduce, ResultType(std::forward<InitialValueType>(initialValue)),
          options);
-    return future.result();
+    return future.takeResult();
 }
 
 template <typename Iterator, typename MapFunctor, typename ReduceFunctor,
@@ -650,7 +650,7 @@ ResultType blockingMappedReduced(Iterator begin,
         <QtPrivate::MapResultType<Iterator, MapFunctor>, ResultType>
         (QThreadPool::globalInstance(), begin, end, map, reduce,
          ResultType(std::forward<InitialValueType>(initialValue)), options);
-    return future.result();
+    return future.takeResult();
 }
 
 // mapped() for sequences with a different putput sequence type.