diff options
Diffstat (limited to 'src/corelib/doc/snippets/code/src_corelib_tools_qhash.cpp')
| -rw-r--r-- | src/corelib/doc/snippets/code/src_corelib_tools_qhash.cpp | 163 |
1 files changed, 54 insertions, 109 deletions
diff --git a/src/corelib/doc/snippets/code/src_corelib_tools_qhash.cpp b/src/corelib/doc/snippets/code/src_corelib_tools_qhash.cpp index ee9f88fc65..c779b9e3e7 100644 --- a/src/corelib/doc/snippets/code/src_corelib_tools_qhash.cpp +++ b/src/corelib/doc/snippets/code/src_corelib_tools_qhash.cpp @@ -1,52 +1,5 @@ -/**************************************************************************** -** -** Copyright (C) 2020 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) 2020 The Qt Company Ltd. +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause //! [0] QHash<QString, int> hash; @@ -89,7 +42,7 @@ QHash<int, QWidget *> hash; ... for (int i = 0; i < 1000; ++i) { if (hash[i] == okButton) - cout << "Found button at index " << i << Qt::endl; + cout << "Found button at index " << i << endl; } //! [6] @@ -98,17 +51,14 @@ for (int i = 0; i < 1000; ++i) { QHashIterator<QString, int> i(hash); while (i.hasNext()) { i.next(); - cout << i.key() << ": " << i.value() << Qt::endl; + cout << qPrintable(i.key()) << ": " << i.value() << endl; } //! [7] //! [8] -QHash<QString, int>::const_iterator i = hash.constBegin(); -while (i != hash.constEnd()) { - cout << i.key() << ": " << i.value() << Qt::endl; - ++i; -} +for (auto i = hash.cbegin(), end = hash.cend(); i != end; ++i) + cout << qPrintable(i.key()) << ": " << i.value() << endl; //! [8] @@ -122,8 +72,8 @@ hash.insert("plenty", 2000); //! [12] QHash<QString, int> hash; ... -foreach (int value, hash) - cout << value << Qt::endl; +for (int value : std::as_const(hash)) + cout << value << endl; //! [12] @@ -185,7 +135,7 @@ QHash<QString, int> hash; ... QHash<QString, int>::const_iterator i = hash.find("HDR"); while (i != hash.end() && i.key() == "HDR") { - cout << i.value() << Qt::endl; + cout << i.value() << endl; ++i; } //! [16] @@ -198,50 +148,20 @@ hash.insert("February", 2); ... hash.insert("December", 12); -QHash<QString, int>::iterator i; -for (i = hash.begin(); i != hash.end(); ++i) - cout << i.key() << ": " << i.value() << Qt::endl; +for (auto i = hash.cbegin(), end = hash.cend(); i != end; ++i) + cout << qPrintable(key()) << ": " << i.value() << endl; //! [17] //! [18] -QHash<QString, int>::iterator i; -for (i = hash.begin(); i != hash.end(); ++i) +for (auto i = hash.begin(), end = hash.end(); i != end; ++i) i.value() += 2; //! [18] - -//! [19] -QHash<QString, int>::iterator i = hash.begin(); -while (i != hash.end()) { - if (i.key().startsWith('_')) - i = hash.erase(i); - else - ++i; -} -//! [19] - - -//! [20] -QHash<QString, int>::iterator i = hash.begin(); -while (i != hash.end()) { - QHash<QString, int>::iterator prev = i; - ++i; - if (prev.key().startsWith('_')) - hash.erase(prev); -} -//! [20] - - //! [21] -// WRONG -while (i != hash.end()) { - if (i.key().startsWith('_')) - hash.erase(i); - ++i; -} +erase_if(hash, [](const QHash<QString, int>::iterator it) { return it.value() > 10; }); //! [21] - +} //! [22] if (i.key() == "Hello") @@ -256,9 +176,8 @@ hash.insert("February", 2); ... hash.insert("December", 12); -QHash<QString, int>::const_iterator i; -for (i = hash.constBegin(); i != hash.constEnd(); ++i) - cout << i.key() << ": " << i.value() << Qt::endl; +for (auto i = hash.cbegin(), end = hash.cend(); i != end; ++i) + cout << qPrintable(i.key()) << ": " << i.value() << endl; //! [23] @@ -279,24 +198,24 @@ hash3 = hash1 + hash2; //! [25] QList<int> values = hash.values("plenty"); -for (int i = 0; i < values.size(); ++i) - cout << values.at(i) << Qt::endl; +for (auto i : std::as_const(values)) + cout << i << endl; //! [25] //! [26] -QMultiHash<QString, int>::iterator i = hash.find("plenty"); -while (i != hash.end() && i.key() == "plenty") { - cout << i.value() << Qt::endl; +auto i = hash.constFind("plenty"); +while (i != hash.cend() && i.key() == "plenty") { + cout << i.value() << endl; ++i; } //! [26] //! [27] -for (QHash<int, QString>::const_iterator it = hash.cbegin(), end = hash.cend(); it != end; ++it) { - cout << "The key: " << it.key() << Qt::endl - cout << "The value: " << it.value() << Qt::endl; - cout << "Also the value: " << (*it) << Qt::endl; +for (auto it = hash.cbegin(), end = hash.cend(); it != end; ++it) { + cout << "The key: " << it.key() << endl; + cout << "The value: " << qPrintable(it.value()) << endl; + cout << "Also the value: " << qPrintable(*it) << endl; } //! [27] @@ -344,11 +263,11 @@ inline size_t qHash(const std::unordered_set<int> &key, size_t seed = 0) //! [31] //! [32] -size_t qHash(K key); -size_t qHash(const K &key); - size_t qHash(K key, size_t seed); size_t qHash(const K &key, size_t seed); + +size_t qHash(K key); // deprecated, do not use +size_t qHash(const K &key); // deprecated, do not use //! [32] //! [33] @@ -360,3 +279,29 @@ template <> struct hash<K> }; } //! [33] + +//! [34] +QHash<QString, int> hash; +hash.insert("January", 1); +hash.insert("February", 2); +// ... +hash.insert("December", 12); + +for (auto [key, value] : hash.asKeyValueRange()) { + cout << qPrintable(key) << ": " << value << endl; + --value; // convert to JS month indexing +} +//! [34] + +//! [35] +QMultiHash<QString, int> hash; +hash.insert("January", 1); +hash.insert("February", 2); +// ... +hash.insert("December", 12); + +for (auto [key, value] : hash.asKeyValueRange()) { + cout << qPrintable(key) << ": " << value << endl; + --value; // convert to JS month indexing +} +//! [35] |