Use universal references in QtConcurrent

Changed QtConcurrent algorithms to take the passed sequences as
universal references, where it makes sense. In addition to avoiding
to create extra copies when passing rvalues, this change allows
passing temporary container adaptors to QtConcurrent::map (e.g. see
the example in the ticket and the new test-cases).

Task-number: QTBUG-83170
Change-Id: Ia7c0833f4ec1d860294fa5214cd53934b65ff084
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 19 insertions, 19 deletions

diff --git a/src/concurrent/qtconcurrentmap.cpp b/src/concurrent/qtconcurrentmap.cpp
index 43763a441f..43313feeef 100644
--- a/src/concurrent/qtconcurrentmap.cpp
+++ b/src/concurrent/qtconcurrentmap.cpp
@@ -104,12 +104,12 @@
 */
 
 /*!
-  \fn [qtconcurrentmapkernel-3] ThreadEngineStarter<T> QtConcurrent::startMapped(const Sequence &sequence, Functor functor)
+  \fn [qtconcurrentmapkernel-3] ThreadEngineStarter<T> QtConcurrent::startMapped(Sequence &&sequence, Functor functor)
   \internal
 */
 
 /*!
-  \fn [qtconcurrentmapkernel-4] ThreadEngineStarter<ResultType> QtConcurrent::startMappedReduced(const Sequence & sequence, MapFunctor mapFunctor, ReduceFunctor reduceFunctor, ReduceOptions options)
+  \fn [qtconcurrentmapkernel-4] ThreadEngineStarter<ResultType> QtConcurrent::startMappedReduced(Sequence && sequence, MapFunctor mapFunctor, ReduceFunctor reduceFunctor, ReduceOptions options)
   \internal
 */
 
@@ -119,7 +119,7 @@
 */
 
 /*!
-  \fn [qtconcurrentmapkernel-6] ThreadEngineStarter<ResultType> QtConcurrent::startMappedReduced(const Sequence & sequence, MapFunctor mapFunctor, ReduceFunctor reduceFunctor, ResultType &&initialValue, ReduceOptions options)
+  \fn [qtconcurrentmapkernel-6] ThreadEngineStarter<ResultType> QtConcurrent::startMappedReduced(Sequence && sequence, MapFunctor mapFunctor, ReduceFunctor reduceFunctor, ResultType &&initialValue, ReduceOptions options)
   \internal
 */
 
@@ -320,7 +320,7 @@
 */
 
 /*!
-    \fn template <typename Sequence, typename MapFunctor> QFuture<void> QtConcurrent::map(QThreadPool *pool, Sequence &sequence, MapFunctor function)
+    \fn template <typename Sequence, typename MapFunctor> QFuture<void> QtConcurrent::map(QThreadPool *pool, Sequence &&sequence, MapFunctor function)
 
     Calls \a function once for each item in \a sequence.
     All calls to \a function are invoked from the threads taken from the QThreadPool \a pool.
@@ -331,7 +331,7 @@
 */
 
 /*!
-    \fn template <typename Sequence, typename MapFunctor> QFuture<void> QtConcurrent::map(Sequence &sequence, MapFunctor function)
+    \fn template <typename Sequence, typename MapFunctor> QFuture<void> QtConcurrent::map(Sequence &&sequence, MapFunctor function)
 
     Calls \a function once for each item in \a sequence. The \a function takes
     a reference to the item, so that any modifications done to the item
@@ -362,7 +362,7 @@
 */
 
 /*!
-    \fn template <typename Sequence, typename MapFunctor> QFuture<QtPrivate::MapResultType<Sequence, MapFunctor>> QtConcurrent::mapped(QThreadPool *pool, const Sequence &sequence, MapFunctor function)
+    \fn template <typename Sequence, typename MapFunctor> QFuture<QtPrivate::MapResultType<Sequence, MapFunctor>> QtConcurrent::mapped(QThreadPool *pool, Sequence &&sequence, MapFunctor function)
 
     Calls \a function once for each item in \a sequence and returns a future
     with each mapped item as a result. All calls to \a function are invoked from the
@@ -373,7 +373,7 @@
 */
 
 /*!
-    \fn template <typename Sequence, typename MapFunctor> QFuture<QtPrivate::MapResultType<Sequence, MapFunctor>> QtConcurrent::mapped(const Sequence &sequence, MapFunctor function)
+    \fn template <typename Sequence, typename MapFunctor> QFuture<QtPrivate::MapResultType<Sequence, MapFunctor>> QtConcurrent::mapped(Sequence &&sequence, MapFunctor function)
 
     Calls \a function once for each item in \a sequence and returns a future
     with each mapped item as a result. You can use QFuture::const_iterator or
@@ -404,7 +404,7 @@
 */
 
 /*!
-    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
+    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
 
     Calls \a mapFunction once for each item in \a sequence.
     All calls to \a mapFunction are invoked from the threads taken from the QThreadPool \a pool.
@@ -418,7 +418,7 @@
 */
 
 /*!
-    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
+    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
 
     Calls \a mapFunction once for each item in \a sequence. The return value of
     each \a mapFunction is passed to \a reduceFunction.
@@ -431,7 +431,7 @@
 */
 
 /*!
-    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
+    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
 
     Calls \a mapFunction once for each item in \a sequence.
     All calls to \a mapFunction are invoked from the threads taken from the QThreadPool \a pool.
@@ -448,7 +448,7 @@
 */
 
 /*!
-    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::mappedReduced(const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
+    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::mappedReduced(Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
 
     Calls \a mapFunction once for each item in \a sequence. The return value of
     each \a mapFunction is passed to \a reduceFunction.
@@ -532,7 +532,7 @@
 */
 
 /*!
-    \fn template <typename Sequence, typename MapFunctor> void QtConcurrent::blockingMap(QThreadPool *pool, Sequence &sequence, MapFunctor function)
+    \fn template <typename Sequence, typename MapFunctor> void QtConcurrent::blockingMap(QThreadPool *pool, Sequence &&sequence, MapFunctor function)
 
     Calls \a function once for each item in \a sequence.
     All calls to \a function are invoked from the threads taken from the QThreadPool \a pool.
@@ -545,7 +545,7 @@
 */
 
 /*!
-  \fn template <typename Sequence, typename MapFunctor> void QtConcurrent::blockingMap(Sequence &sequence, MapFunctor function)
+  \fn template <typename Sequence, typename MapFunctor> void QtConcurrent::blockingMap(Sequence &&sequence, MapFunctor function)
 
   Calls \a function once for each item in \a sequence. The \a function takes
   a reference to the item, so that any modifications done to the item
@@ -584,7 +584,7 @@
 */
 
 /*!
-    \fn template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(QThreadPool *pool, const InputSequence &sequence, MapFunctor function)
+    \fn template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(QThreadPool *pool, InputSequence &&sequence, MapFunctor function)
 
     Calls \a function once for each item in \a sequence and returns an OutputSequence containing
     the results. All calls to \a function are invoked from the threads taken from the QThreadPool
@@ -596,7 +596,7 @@
 */
 
 /*!
-  \fn template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(const InputSequence &sequence, MapFunctor function)
+  \fn template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(const InputSequence &&sequence, MapFunctor function)
 
   Calls \a function once for each item in \a sequence and returns an OutputSequence containing
   the results. The type of the results will match the type returned my the MapFunctor.
@@ -642,7 +642,7 @@
 */
 
 /*!
-    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
+    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
 
     Calls \a mapFunction once for each item in \a sequence.
     All calls to \a mapFunction are invoked from the threads taken from the QThreadPool \a pool.
@@ -658,7 +658,7 @@
 */
 
 /*!
-  \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
+  \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, QtConcurrent::ReduceOptions reduceOptions)
 
   Calls \a mapFunction once for each item in \a sequence. The return value of
   each \a mapFunction is passed to \a reduceFunction.
@@ -673,7 +673,7 @@
 */
 
 /*!
-    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
+    \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
 
     Calls \a mapFunction once for each item in \a sequence.
     All calls to \a mapFunction are invoked from the threads taken from the QThreadPool \a pool.
@@ -692,7 +692,7 @@
 */
 
 /*!
-  \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingMappedReduced(const Sequence &sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
+  \fn template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingMappedReduced(Sequence &&sequence, MapFunctor mapFunction, ReduceFunctor reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions)
 
   Calls \a mapFunction once for each item in \a sequence. The return value of
   each \a mapFunction is passed to \a reduceFunction.