QtConcurrent Namespace

 template <class Task, class ...Args>
 using InvokeResultType = std::invoke_result_t<std::decay_t<Task>, std::decay_t<Args>...>;

Function Documentation

template <typename Sequence, typename KeepFunctor> void QtConcurrent::blockingFilter(QThreadPool *pool, Sequence &sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true, the item is kept in sequence; otherwise, the item is removed from sequence.

Note that this method doesn't have an overload working with iterators, because it invalidates the iterators of the sequence it operates on.

See also Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename KeepFunctor> void QtConcurrent::blockingFilter(Sequence &sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence. If filterFunction returns true, the item is kept in sequence; otherwise, the item is removed from sequence.

Note that this method doesn't have an overload working with iterators, because it invalidates the iterators of the sequence it operates on.

See also Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename KeepFunctor> std::decay_t<Sequence> QtConcurrent::blockingFiltered(QThreadPool *pool, Sequence &&sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence and returns a new Sequence of kept items. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also filtered() and Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename KeepFunctor> std::decay_t<Sequence> QtConcurrent::blockingFiltered(Sequence &&sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence and returns a new Sequence of kept items. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also filtered() and Concurrent Filter and Filter-Reduce.

template <typename OutputSequence, typename Iterator, typename KeepFunctor> OutputSequence QtConcurrent::blockingFiltered(QThreadPool *pool, Iterator begin, Iterator end, KeepFunctor &&filterFunction)

Calls filterFunction once for each item from begin to end and returns a new Sequence of kept items. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also filtered() and Concurrent Filter and Filter-Reduce.

template <typename OutputSequence, typename Iterator, typename KeepFunctor> OutputSequence QtConcurrent::blockingFiltered(Iterator begin, Iterator end, KeepFunctor &&filterFunction)

Calls filterFunction once for each item from begin to end and returns a new Sequence of kept items. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also filtered() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingFilteredReduced(QThreadPool *pool, Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingFilteredReduced(Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingFilteredReduced(QThreadPool *pool, Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingFilteredReduced(Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingFilteredReduced(QThreadPool *pool, Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingFilteredReduced(Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingFilteredReduced(QThreadPool *pool, Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingFilteredReduced(Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also filteredReduced() and Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename MapFunctor> void QtConcurrent::blockingMap(QThreadPool *pool, Sequence &&sequence, MapFunctor function)

Calls function once for each item in sequence. All calls to function are invoked from the threads taken from the QThreadPool pool. The function takes a reference to the item, so that any modifications done to the item will appear in sequence.

See also map() and Concurrent Map and Map-Reduce.

template <typename Sequence, typename MapFunctor> void QtConcurrent::blockingMap(Sequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence. The function takes a reference to the item, so that any modifications done to the item will appear in sequence.

See also map() and Concurrent Map and Map-Reduce.

template <typename Iterator, typename MapFunctor> void QtConcurrent::blockingMap(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end. All calls to function are invoked from the threads taken from the QThreadPool pool. The function takes a reference to the item, so that any modifications done to the item will appear in the sequence which the iterators belong to.

See also map() and Concurrent Map and Map-Reduce.

template <typename Iterator, typename MapFunctor> void QtConcurrent::blockingMap(Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end. The function takes a reference to the item, so that any modifications done to the item will appear in the sequence which the iterators belong to.

See also map() and Concurrent Map and Map-Reduce.

template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(QThreadPool *pool, InputSequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence and returns an OutputSequence containing the results. All calls to function are invoked from the threads taken from the QThreadPool pool. The type of the results will match the type returned by the MapFunctor.

See also mapped() and Concurrent Map and Map-Reduce.

template <typename OutputSequence, typename InputSequence, typename MapFunctor> OutputSequence QtConcurrent::blockingMapped(InputSequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence and returns an OutputSequence containing the results. The type of the results will match the type returned by the MapFunctor.

See also mapped() and Concurrent Map and Map-Reduce.

template <typename Sequence, typename Iterator, typename MapFunctor> Sequence QtConcurrent::blockingMapped(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end and returns a container with the results. All calls to function are invoked from the threads taken from the QThreadPool pool. You can specify the type of container as the a template argument, like this:

 QList<int> ints = QtConcurrent::blockingMapped<QList<int> >(beginIterator, endIterator, fn);

See also mapped() and Concurrent Map and Map-Reduce.

template <typename Sequence, typename Iterator, typename MapFunctor> Sequence QtConcurrent::blockingMapped(Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end and returns a container with the results. You can specify the type of container as the a template argument, like this:

 QList<int> ints = QtConcurrent::blockingMapped<QList<int> >(beginIterator, endIterator, fn);

See also mapped() and Concurrent Map and Map-Reduce.

template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, Sequence &&sequence, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also mapped() and Concurrent Map and Map-Reduce.

template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(Sequence &&sequence, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also mapped() and Concurrent Map and Map-Reduce.

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 = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also mapped() and Concurrent Map and Map-Reduce.

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 = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also mapped() and Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined.

See also blockingMappedReduced() and Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor> ResultType QtConcurrent::blockingMappedReduced(Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined.

See also blockingMappedReduced() and Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingMappedReduced(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined.

See also blockingMappedReduced() and Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> ResultType QtConcurrent::blockingMappedReduced(Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined.

See also blockingMappedReduced() and Concurrent Map and Map-Reduce.

template <typename Sequence, typename KeepFunctor> QFuture<void> QtConcurrent::filter(QThreadPool *pool, Sequence &sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true, the item is kept in sequence; otherwise, the item is removed from sequence.

Note that this method doesn't have an overload working with iterators, because it invalidates the iterators of the sequence it operates on.

See also Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename KeepFunctor> QFuture<void> QtConcurrent::filter(Sequence &sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence. If filterFunction returns true, the item is kept in sequence; otherwise, the item is removed from sequence.

Note that this method doesn't have an overload working with iterators, because it invalidates the iterators of the sequence it operates on.

See also Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename KeepFunctor> QFuture<typename std::decay_t<Sequence>::value_type> QtConcurrent::filtered(QThreadPool *pool, Sequence &&sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence and returns a new Sequence of kept items. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename KeepFunctor> QFuture<typename std::decay_t<Sequence>::value_type> QtConcurrent::filtered(Sequence &&sequence, KeepFunctor &&filterFunction)

Calls filterFunction once for each item in sequence and returns a new Sequence of kept items. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename Iterator, typename KeepFunctor> QFuture<typename qValueType<Iterator>::value_type> QtConcurrent::filtered(QThreadPool *pool, Iterator begin, Iterator end, KeepFunctor &&filterFunction)

Calls filterFunction once for each item from begin to end and returns a new Sequence of kept items. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename Iterator, typename KeepFunctor> QFuture<typename qValueType<Iterator>::value_type> QtConcurrent::filtered(Iterator begin, Iterator end, KeepFunctor &&filterFunction)

Calls filterFunction once for each item from begin to end and returns a new Sequence of kept items. If filterFunction returns true, a copy of the item is put in the new Sequence. Otherwise, the item will not appear in the new Sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::filteredReduced(QThreadPool *pool, Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::filteredReduced(Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::filteredReduced(QThreadPool *pool, Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Sequence, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::filteredReduced(Sequence &&sequence, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item in sequence. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::filteredReduced(QThreadPool *pool, Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::filteredReduced(Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::filteredReduced(QThreadPool *pool, Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. All calls to filterFunction are invoked from the threads taken from the QThreadPool pool. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename ResultType, typename Iterator, typename KeepFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::filteredReduced(Iterator begin, Iterator end, KeepFunctor &&filterFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls filterFunction once for each item from begin to end. If filterFunction returns true for an item, that item is then passed to reduceFunction. In other words, the return value is the result of reduceFunction for each item where filterFunction returns true. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while filterFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is undefined if reduceOptions is QtConcurrent::UnorderedReduce. If reduceOptions is QtConcurrent::OrderedReduce, the reduceFunction is called in the order of the original sequence.

See also Concurrent Filter and Filter-Reduce.

template <typename Sequence, typename MapFunctor> QFuture<void> QtConcurrent::map(QThreadPool *pool, Sequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence. All calls to function are invoked from the threads taken from the QThreadPool pool. The function takes a reference to the item, so that any modifications done to the item will appear in sequence.

See also Concurrent Map and Map-Reduce.

template <typename Sequence, typename MapFunctor> QFuture<void> QtConcurrent::map(Sequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence. The function takes a reference to the item, so that any modifications done to the item will appear in sequence.

See also Concurrent Map and Map-Reduce.

template <typename Iterator, typename MapFunctor> QFuture<void> QtConcurrent::map(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end. All calls to function are invoked from the threads taken from the QThreadPool pool. The function takes a reference to the item, so that any modifications done to the item will appear in the sequence which the iterators belong to.

See also Concurrent Map and Map-Reduce.

template <typename Iterator, typename MapFunctor> QFuture<void> QtConcurrent::map(Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end. The function takes a reference to the item, so that any modifications done to the item will appear in the sequence which the iterators belong to.

See also Concurrent Map and Map-Reduce.

template <typename Sequence, typename MapFunctor> QFuture<QtPrivate::MapResultType<Sequence, MapFunctor>> QtConcurrent::mapped(QThreadPool *pool, Sequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence and returns a future with each mapped item as a result. All calls to function are invoked from the threads taken from the QThreadPool pool. You can use QFuture::const_iterator or QFutureIterator to iterate through the results.

See also Concurrent Map and Map-Reduce.

template <typename Sequence, typename MapFunctor> QFuture<QtPrivate::MapResultType<Sequence, MapFunctor>> QtConcurrent::mapped(Sequence &&sequence, MapFunctor &&function)

Calls function once for each item in sequence and returns a future with each mapped item as a result. You can use QFuture::const_iterator or QFutureIterator to iterate through the results.

See also Concurrent Map and Map-Reduce.

template <typename Iterator, typename MapFunctor> QFuture<QtPrivate::MapResultType<Iterator, MapFunctor>> QtConcurrent::mapped(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end and returns a future with each mapped item as a result. All calls to function are invoked from the threads taken from the QThreadPool pool. You can use QFuture::const_iterator or QFutureIterator to iterate through the results.

See also Concurrent Map and Map-Reduce.

template <typename Iterator, typename MapFunctor> QFuture<QtPrivate::MapResultType<Iterator, MapFunctor>> QtConcurrent::mapped(Iterator begin, Iterator end, MapFunctor &&function)

Calls function once for each item from begin to end and returns a future with each mapped item as a result. You can use QFuture::const_iterator or QFutureIterator to iterate through the results.

See also Concurrent Map and Map-Reduce.

template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, Sequence &&sequence, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also Concurrent Map and Map-Reduce.

template <typename ResultType, typename Sequence, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(Sequence &&sequence, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also Concurrent Map and Map-Reduce.

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 = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also Concurrent Map and Map-Reduce.

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 = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item in sequence. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. The order in which reduceFunction is called is determined by reduceOptions.

See also Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. By default, the order in which reduceFunction is called is undefined.

See also Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor> QFuture<ResultType> QtConcurrent::mappedReduced(Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. The return value of each mapFunction is passed to reduceFunction.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. By default, the order in which reduceFunction is called is undefined.

See also Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::mappedReduced(QThreadPool *pool, Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. All calls to mapFunction are invoked from the threads taken from the QThreadPool pool. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. By default, the order in which reduceFunction is called is undefined.

See also Concurrent Map and Map-Reduce.

template <typename ResultType, typename Iterator, typename MapFunctor, typename ReduceFunctor, typename InitialValueType> QFuture<ResultType> QtConcurrent::mappedReduced(Iterator begin, Iterator end, MapFunctor &&mapFunction, ReduceFunctor &&reduceFunction, InitialValueType &&initialValue, QtConcurrent::ReduceOptions reduceOptions = ReduceOptions(UnorderedReduce | SequentialReduce))

Calls mapFunction once for each item from begin to end. The return value of each mapFunction is passed to reduceFunction. The result value is initialized to initialValue when the function is called, and the first call to reduceFunction will operate on this value.

Note that while mapFunction is called concurrently, only one thread at a time will call reduceFunction. By default, the order in which reduceFunction is called is undefined.

See also Concurrent Map and Map-Reduce.

template <typename T> QFuture<T> QtConcurrent::run(Function function, ...)

Equivalent to

 QtConcurrent::run(QThreadPool::globalInstance(), function, ...);

Runs function in a separate thread. The thread is taken from the global QThreadPool. Note that function may not run immediately; function will only be run once a thread becomes available.

In basic mode T is the same type as the return value of function. Non-void return values can be accessed via the QFuture::result() function.

In basic mode the QFuture returned can only be used to query for the running/finished status and the return value of the function. In particular, canceling or pausing can be issued only if the computations behind the future has not been started.

In run with promise mode, the function is expected to return void and must take an additional argument of QPromise<T> & type, placed as a first argument in function's argument list. T is the result type and it is the same for the returned QFuture<T>.

In run with promise mode, similar to basic mode, the QFuture returned can be used to query for the running/finished status and the value reported by the function. In addition, it may be used for suspending or canceling the running task, fetching multiple results from the called function or monitoring progress reported by the function.

See also Concurrent Run (basic mode), Concurrent Run With Promise, and QThreadPool::start().

template <typename T> QFuture<T> QtConcurrent::run(QThreadPool *pool, Function function, ...)

Schedules function on pool. Note that function may not run immediately; function will only be run once a thread becomes available.

In basic mode T is the same type as the return value of function. Non-void return values can be accessed via the QFuture::result() function.

In basic mode the QFuture returned can only be used to query for the running/finished status and the return value of the function. In particular, canceling or pausing can be issued only if the computations behind the future has not been started.

In run with promise mode, the function is expected to return void and must take an additional argument of QPromise<T> & type, placed as a first argument in function's argument list. T is the result type and it is the same for the returned QFuture<T>.

In run with promise mode, similar to basic mode, the QFuture returned can be used to query for the running/finished status and the value reported by the function. In addition, it may be used for suspending or canceling the running task, fetching multiple results from the called function or monitoring progress reported by the function.

See also Concurrent Run (basic mode), Concurrent Run With Promise, and QThreadPool::start().

[since 6.0] template <typename Task> QtConcurrent::QTaskBuilder<Task> QtConcurrent::task(Task &&task)

Creates an instance of QtConcurrent::QTaskBuilder. This object can be used to adjust some parameters and run task in a separate thread.

This function was introduced in Qt 6.0.

See also Concurrent Task and QtConcurrent::QTaskBuilder.