2 files changed, 393 insertions, 0 deletions
diff --git a/src/corelib/doc/snippets/code/doc_src_qiterator.cpp b/src/corelib/doc/snippets/code/doc_src_qiterator.cpp
index ed0cf9e329..2ee618d394 100644
--- a/src/corelib/doc/snippets/code/doc_src_qiterator.cpp
+++ b/src/corelib/doc/snippets/code/doc_src_qiterator.cpp
@@ -183,6 +183,35 @@ while (i.findNext(widget)) {
 }
 //! [28]
 
+//! [26multi]
+QMultiMap<int, QWidget *> multimap;
+...
+QMultiMapIterator<int, QWidget *> i(multimap);
+while (i.hasNext()) {
+    i.next();
+    qDebug() << i.key() << ": " << i.value();
+}
+//! [26multi]
+
+
+//! [27multi]
+QMultiMapIterator<int, QWidget *> i(multimap);
+i.toBack();
+while (i.hasPrevious()) {
+    i.previous();
+    qDebug() << i.key() << ": " << i.value();
+}
+//! [27multi]
+
+
+//! [28multi]
+QMultiMapIterator<int, QWidget *> i(multimap);
+while (i.findNext(widget)) {
+    qDebug() << "Found widget " << widget << " under key "
+             << i.key();
+}
+//! [28multi]
+
 
 //! [29]
 QHash<int, QWidget *> hash;
@@ -244,6 +273,46 @@ while (i.hasNext()) {
 //! [35]
 
 
+//! [32multi]
+QMultiMap<int, QWidget *> multimap;
+...
+QMutableMultiMapIterator<int, QWidget *> i(multimap);
+while (i.hasNext()) {
+    i.next();
+    qDebug() << i.key() << ": " << i.value();
+}
+//! [32multi]
+
+
+//! [33multi]
+QMutableMultiMapIterator<int, QWidget *> i(multimap);
+i.toBack();
+while (i.hasPrevious()) {
+    i.previous();
+    qDebug() << i.key() << ": " << i.value();
+}
+//! [33multi]
+
+
+//! [34multi]
+QMutableMultiMapIterator<int, QWidget *> i(multimap);
+while (i.findNext(widget)) {
+    qDebug() << "Found widget " << widget << " under key "
+             << i.key();
+}
+//! [34multi]
+
+
+//! [35multi]
+QMutableMultiMapIterator<QString, QString> i(multimap);
+while (i.hasNext()) {
+    i.next();
+    if (i.key() == i.value())
+        i.remove();
+}
+//! [35multi]
+
+
 //! [36]
 QHash<int, QWidget *> hash;
 ...
diff --git a/src/corelib/doc/snippets/code/src_corelib_tools_qmultimap.cpp b/src/corelib/doc/snippets/code/src_corelib_tools_qmultimap.cpp
new file mode 100644
index 0000000000..9c2a01834b
--- /dev/null
+++ b/src/corelib/doc/snippets/code/src_corelib_tools_qmultimap.cpp
@@ -0,0 +1,324 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
+** 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."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [0]
+QMultiMap<QString, int> multimap;
+//! [0]
+
+
+//! [2]
+multimap.insert("a", 1);
+multimap.insert("b", 3);
+multimap.insert("c", 7);
+multimap.insert("c", -5);
+//! [2]
+
+
+//! [3]
+int num2 = multimap.value("a"); // 1
+int num3 = multimap.value("thirteen"); // not found; 0
+int num3 = 0;
+auto it = multimap.value("b");
+if (it != multimap.end()) {
+    num3 = it.value();
+}
+//! [3]
+
+
+//! [4]
+int timeout = 30;
+if (multimap.contains("TIMEOUT"))
+    timeout = multimap.value("TIMEOUT");
+
+// better:
+auto it = multimap.find("TIMEOUT");
+if (it != multimap.end())
+    timeout = it.value();
+//! [4]
+
+
+//! [5]
+int timeout = multimap.value("TIMEOUT", 30);
+//! [5]
+
+
+//! [7]
+QMultiMapIterator<QString, int> i(multimap);
+while (i.hasNext()) {
+    i.next();
+    cout << i.key() << ": " << i.value() << Qt::endl;
+}
+//! [7]
+
+
+//! [8]
+auto i = multimap.constBegin();
+while (i != multimap.constEnd()) {
+    cout << i.key() << ": " << i.value() << Qt::endl;
+    ++i;
+}
+//! [8]
+
+
+//! [9]
+multimap.insert("plenty", 100);
+multimap.insert("plenty", 2000);
+// multimap.size() == 2
+//! [9]
+
+
+//! [10]
+QList<int> values = multimap.values("plenty");
+for (int i = 0; i < values.size(); ++i)
+    cout << values.at(i) << Qt::endl;
+//! [10]
+
+
+//! [11]
+QMultiMap<QString, int>::iterator i = multimap.find("plenty");
+while (i != map.end() && i.key() == "plenty") {
+    cout << i.value() << Qt::endl;
+    ++i;
+}
+
+// better:
+auto [i, end] = multimap.equal_range("plenty");
+while (i != end) {
+    cout << i.value() << Qt::endl;
+    ++i;
+}
+//! [11]
+
+
+//! [12]
+QMap<QString, int> multimap;
+...
+foreach (int value, multimap)
+    cout << value << Qt::endl;
+//! [12]
+
+
+//! [13]
+#ifndef EMPLOYEE_H
+#define EMPLOYEE_H
+
+class Employee
+{
+public:
+    Employee() {}
+    Employee(const QString &name, QDate dateOfBirth);
+    ...
+
+private:
+    QString myName;
+    QDate myDateOfBirth;
+};
+
+inline bool operator<(const Employee &e1, const Employee &e2)
+{
+    if (e1.name() != e2.name())
+        return e1.name() < e2.name();
+    return e1.dateOfBirth() < e2.dateOfBirth();
+}
+
+#endif // EMPLOYEE_H
+//! [13]
+
+
+//! [15]
+QMultiMap<int, QString> multimap;
+multimap.insert(1, "one");
+multimap.insert(5, "five");
+multimap.insert(5, "five (2)");
+multimap.insert(10, "ten");
+
+multimap.lowerBound(0);      // returns iterator to (1, "one")
+multimap.lowerBound(1);      // returns iterator to (1, "one")
+multimap.lowerBound(2);      // returns iterator to (5, "five")
+multimap.lowerBound(5);      // returns iterator to (5, "five")
+multimap.lowerBound(6);      // returns iterator to (10, "ten")
+multimap.lowerBound(10);     // returns iterator to (10, "ten")
+multimap.lowerBound(999);    // returns end()
+//! [15]
+
+
+//! [16]
+QMap<QString, int> multimap;
+...
+QMap<QString, int>::const_iterator i = multimap.lowerBound("HDR");
+QMap<QString, int>::const_iterator upperBound = multimap.upperBound("HDR");
+while (i != upperBound) {
+    cout << i.value() << Qt::endl;
+    ++i;
+}
+//! [16]
+
+
+//! [17]
+QMultiMap<int, QString> multimap;
+multimap.insert(1, "one");
+multimap.insert(5, "five");
+multimap.insert(5, "five (2)");
+multimap.insert(10, "ten");
+
+multimap.upperBound(0);      // returns iterator to (1, "one")
+multimap.upperBound(1);      // returns iterator to (5, "five")
+multimap.upperBound(2);      // returns iterator to (5, "five")
+multimap.lowerBound(5);      // returns iterator to (5, "five (2)")
+multimap.lowerBound(6);      // returns iterator to (10, "ten")
+multimap.upperBound(10);     // returns end()
+multimap.upperBound(999);    // returns end()
+//! [17]
+
+
+//! [18]
+QMultiMap<QString, int> multimap;
+multimap.insert("January", 1);
+multimap.insert("February", 2);
+...
+multimap.insert("December", 12);
+
+QMap<QString, int>::iterator i;
+for (i = multimap.begin(); i != multimap.end(); ++i)
+    cout << i.key() << ": " << i.value() << Qt::endl;
+//! [18]
+
+
+//! [19]
+QMultiMap<QString, int>::iterator i;
+for (i = multimap.begin(); i != multimap.end(); ++i)
+    i.value() += 2;
+//! [19]
+
+
+//! [20]
+QMultiMap<QString, int>::iterator i = multimap.begin();
+while (i != multimap.end()) {
+    if (i.key().startsWith('_'))
+        i = multimap.erase(i);
+    else
+        ++i;
+}
+//! [20]
+
+
+//! [21]
+QMultiMap<QString, int>::iterator i = multimap.begin();
+while (i != multimap.end()) {
+    QMap<QString, int>::iterator prev = i;
+    ++i;
+    if (prev.key().startsWith('_'))
+        multimap.erase(prev);
+}
+//! [21]
+
+
+//! [22]
+// WRONG
+while (i != multimap.end()) {
+    if (i.key().startsWith('_'))
+        multimap.erase(i);
+    ++i;
+}
+//! [22]
+
+
+//! [23]
+if (i.key() == "Hello")
+    i.value() = "Bonjour";
+//! [23]
+
+
+//! [24]
+QMultiMap<QString, int> multi;
+multimap.insert("January", 1);
+multimap.insert("February", 2);
+...
+multimap.insert("December", 12);
+
+QMultiMap<QString, int>::const_iterator i;
+for (i = multimap.constBegin(); i != multimap.constEnd(); ++i)
+    cout << i.key() << ": " << i.value() << Qt::endl;
+//! [24]
+
+
+//! [25]
+QMultiMap<QString, int> map1, map2, map3;
+
+map1.insert("plenty", 100);
+map1.insert("plenty", 2000);
+// map1.size() == 2
+
+map2.insert("plenty", 5000);
+// map2.size() == 1
+
+map3 = map1 + map2;
+// map3.size() == 3
+//! [25]
+
+//! [keyiterator1]
+for (QMultiMap<int, QString>::const_iterator it = multimap.cbegin(), end = multimap.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;
+}
+//! [keyiterator1]
+
+//! [keyiterator2]
+// Inefficient, keys() is expensive
+QList<int> keys = multimap.keys();
+int numPrimes = std::count_if(multimap.cbegin(), multimap.cend(), isPrimeNumber);
+qDeleteAll(multimap2.keys());
+
+// Efficient, no memory allocation needed
+int numPrimes = std::count_if(multimap.keyBegin(), multimap.keyEnd(), isPrimeNumber);
+qDeleteAll(multimap2.keyBegin(), multimap2.keyEnd());
+//! [keyiterator2]