blob: cb1889afb6eeeeb7e2719b9243f9412ae28c8480 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
// Copyright (C) 2020 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
//! [0]
QtConcurrent::task([]{ qDebug("Hello, world!"); }).spawn();
//! [0]
//! [1]
auto task = [](const QString &s){ qDebug() << ("Hello, " + s); };
QtConcurrent::task(std::move(task))
.withArguments("world!")
.spawn();
//! [1]
//! [2]
QString s("Hello, ");
QtConcurrent::task([](QString &s){ s.append("world!"); })
.withArguments(std::ref(s))
.spawn();
//! [2]
//! [3]
auto future = QtConcurrent::task([]{ return 42; }).spawn();
auto result = future.result(); // result == 42
//! [3]
//! [4]
std::is_invocable_v<std::decay_t<Task>, std::decay_t<Args>...>
//! [4]
//! [5]
QVariant value(42);
auto result = QtConcurrent::task([](const QVariant &var){return qvariant_cast<int>(var);})
.withArguments(value)
.spawn()
.result(); // result == 42
//! [5]
//! [6]
QString result("Hello, world!");
QtConcurrent::task(&QString::chop)
.withArguments(&result, 8)
.spawn()
.waitForFinished(); // result == "Hello"
//! [6]
//! [7]
auto result = QtConcurrent::task(std::plus<int>())
.withArguments(40, 2)
.spawn()
.result() // result == 42
//! [7]
//! [8]
struct CallableWithState
{
void operator()(int newState) { state = newState; }
// ...
};
// ...
CallableWithState object;
QtConcurrent::task(std::ref(object))
.withArguments(42)
.spawn()
.waitForFinished(); // The object's state is set to 42
//! [8]
//! [9]
QThreadPool pool;
QtConcurrent::task([]{ return 42; }).onThreadPool(pool).spawn();
//! [9]
//! [10]
QtConcurrent::task([]{ return 42; }).withPriority(10).spawn();
//! [10]
//! [11]
QtConcurrent::task([]{ qDebug("Hello, world!"); }).spawn(FutureResult::Ignore);
//! [11]
//! [12]
void increment(QPromise<int> &promise, int i)
{
promise.addResult(i + 1);
}
int result = QtConcurrent::task(&increment).withArguments(10).spawn().result(); // result == 11
//! [12]
|
