QtConcurrent::QTaskBuilder Class | Qt Concurrent | Qt 6.12.0
Description: The QTaskBuilder class is used for adjusting task parameters.
Keywords: class

- Qt 6.12
- Qt Concurrent
- C++ Classes
- QTaskBuilder
- Qt 6.12.0 Reference Documentation

# QtConcurrent::QTaskBuilder Class

template <typename Task, typename... Args> class QtConcurrent::QTaskBuilder

The QTaskBuilder class is used for adjusting task parameters. More...

Header: | `#include <qtaskbuilder.h>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS Concurrent)` `target_link_libraries(mytarget PRIVATE Qt6::Concurrent)`
qmake: | `QT += concurrent`
Since: | Qt 6.0

- List of all members, including inherited members
- QTaskBuilder is part of Threading Classes.

## Public Functions

QtConcurrent::QTaskBuilder<Task, Args...> & | onThreadPool(QThreadPool &newThreadPool)
QFuture<QtConcurrent::InvokeResultType> | spawn()
void | spawn(QtConcurrent::FutureResult)
QtConcurrent::QTaskBuilder<Task, ExtraArgs...> | withArguments(ExtraArgs &&... args)
QtConcurrent::QTaskBuilder<Task, Args...> & | withPriority(int newPriority)

## Related Non-Members

| InvokeResultType

## Detailed Description

The template parameter Task specifies the callable type, and Args specifies the argument types that the task will be invoked with.

It's not possible to create an object of this class manually. See Concurrent Task for more details and usage examples.

## Member Function Documentation

### QtConcurrent::QTaskBuilder<Task, Args...> &QTaskBuilder::onThreadPool(QThreadPool &newThreadPool)

Sets the thread pool newThreadPool that the task will be invoked on.

### QFuture<QtConcurrent::InvokeResultType> QTaskBuilder::spawn()

Runs the task in a separate thread and returns a future object immediately. This is a non-blocking call. The task might not start immediately.

### void QTaskBuilder::spawn(QtConcurrent::FutureResult)

Runs the task in a separate thread. This is a non-blocking call. The task might not start immediately.

### template <typename... ExtraArgs> QtConcurrent::QTaskBuilder<Task, ExtraArgs...> QTaskBuilder::withArguments(ExtraArgs &&... args)

Sets the arguments args the task will be invoked with. The code is ill-formed (causes compilation errors) if:

- This function is invoked more than once.
- The arguments count is zero.

### QtConcurrent::QTaskBuilder<Task, Args...> &QTaskBuilder::withPriority(int newPriority)

Sets the priority newPriority that the task will be invoked with.

## Related Non-Members

### `[alias]` InvokeResultType

The simplified definition of this type looks like this:

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

The real implementation also contains a compile-time check for whether the task can be invoked with the specified arguments or not.