diff options
Diffstat (limited to 'src/concurrent/doc/snippets/code/src_concurrent_qtconcurrentfilter.cpp')
| -rw-r--r-- | src/concurrent/doc/snippets/code/src_concurrent_qtconcurrentfilter.cpp | 121 |
1 files changed, 63 insertions, 58 deletions
diff --git a/src/concurrent/doc/snippets/code/src_concurrent_qtconcurrentfilter.cpp b/src/concurrent/doc/snippets/code/src_concurrent_qtconcurrentfilter.cpp index 3cc1fe836c..1ea7deace5 100644 --- a/src/concurrent/doc/snippets/code/src_concurrent_qtconcurrentfilter.cpp +++ b/src/concurrent/doc/snippets/code/src_concurrent_qtconcurrentfilter.cpp @@ -1,52 +1,5 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:BSD$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** BSD License Usage -** Alternatively, you may use this file under the terms of the BSD license -** as follows: -** -** "Redistribution and use in source and binary forms, with or without -** modification, are permitted provided that the following conditions are -** met: -** * Redistributions of source code must retain the above copyright -** notice, this list of conditions and the following disclaimer. -** * Redistributions in binary form must reproduce the above copyright -** notice, this list of conditions and the following disclaimer in -** the documentation and/or other materials provided with the -** distribution. -** * Neither the name of The Qt Company Ltd nor the names of its -** contributors may be used to endorse or promote products derived -** from this software without specific prior written permission. -** -** -** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." -** -** $QT_END_LICENSE$ -** -****************************************************************************/ +// Copyright (C) 2016 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause //! [0] bool function(const T &t); @@ -82,7 +35,7 @@ void addToDictionary(QSet<QString> &dictionary, const QString &string) } QStringList strings = ...; -QFuture<QSet<QString> > dictionary = QtConcurrent::filteredReduced(strings, allLowerCase, addToDictionary); +QFuture<QSet<QString>> dictionary = QtConcurrent::filteredReduced(strings, allLowerCase, addToDictionary); //! [4] @@ -93,7 +46,7 @@ QFuture<QString> lowerCaseStrings = QtConcurrent::filtered(strings.constBegin(), // filter in-place only works on non-const iterators QFuture<void> future = QtConcurrent::filter(strings.begin(), strings.end(), allLowerCase); -QFuture<QSet<QString> > dictionary = QtConcurrent::filteredReduced(strings.constBegin(), strings.constEnd(), allLowerCase, addToDictionary); +QFuture<QSet<QString>> dictionary = QtConcurrent::filteredReduced(strings.constBegin(), strings.constEnd(), allLowerCase, addToDictionary); //! [5] @@ -121,7 +74,8 @@ QFuture<QImage> grayscaleImages = QtConcurrent::filtered(images, &QImage::isGray // create a set of all printable characters QList<QChar> characters = ...; -QFuture<QSet<QChar> > set = QtConcurrent::filteredReduced(characters, &QChar::isPrint, &QSet<QChar>::insert); +QFuture<QSet<QChar>> set = QtConcurrent::filteredReduced(characters, qOverload<>(&QChar::isPrint), + qOverload<const QChar&>(&QSet<QChar>::insert)); //! [7] @@ -131,7 +85,8 @@ QFuture<QSet<QChar> > set = QtConcurrent::filteredReduced(characters, &QChar::is // create a dictionary of all lower cased strings extern bool allLowerCase(const QString &string); QStringList strings = ...; -QFuture<QSet<int> > averageWordLength = QtConcurrent::filteredReduced(strings, allLowerCase, QSet<QString>::insert); +QFuture<QSet<QString>> lowerCase = QtConcurrent::filteredReduced(strings, allLowerCase, + qOverload<const QString&>(&QSet<QString>::insert)); // create a collage of all gray scale images extern void addToCollage(QImage &collage, const QImage &grayscaleImage); @@ -158,8 +113,6 @@ struct StartsWith StartsWith(const QString &string) : m_string(string) { } - typedef bool result_type; - bool operator()(const QString &testString) { return testString.startsWith(m_string); @@ -179,7 +132,59 @@ struct StringTransform }; QFuture<QString> fooString = - QtConcurrent::filteredReduced<QString>(strings, - StartsWith(QLatin1String("Foo")), - StringTransform()); + QtConcurrent::filteredReduced(strings, StartsWith(QLatin1String("Foo")), StringTransform()); //! [14] + +//! [15] +// keep only even integers +QList<int> list { 1, 2, 3, 4 }; +QtConcurrent::blockingFilter(list, [](int n) { return (n & 1) == 0; }); + +// retrieve only even integers +QList<int> list2 { 1, 2, 3, 4 }; +QFuture<int> future = QtConcurrent::filtered(list2, [](int x) { + return (x & 1) == 0; +}); +QList<int> results = future.results(); + +// add up all even integers +QList<int> list3 { 1, 2, 3, 4 }; +QFuture<int> sum = QtConcurrent::filteredReduced(list3, + [](int x) { + return (x & 1) == 0; + }, + [](int &sum, int x) { + sum += x; + } +); +//! [15] + +//! [16] +void intSumReduce(int &sum, int x) +{ + sum += x; +} + +QList<int> list { 1, 2, 3, 4 }; +QFuture<int> sum = QtConcurrent::filteredReduced(list, + [] (int x) { + return (x & 1) == 0; + }, + intSumReduce +); +//! [16] + +//! [17] +bool keepEvenIntegers(int x) +{ + return (x & 1) == 0; +} + +QList<int> list { 1, 2, 3, 4 }; +QFuture<int> sum = QtConcurrent::filteredReduced(list, + keepEvenIntegers, + [](int &sum, int x) { + sum += x; + } +); +//! [17] |