From 8183086513ae439220ae1facb1e93fc23b9a116b Mon Sep 17 00:00:00 2001
From: Ole-Morten Duesund <olemd@odinprosjekt.no>
Date: Mon, 7 Dec 2020 15:47:28 +0100
Subject: Add sections about std containers and algorithms

Add section comparing Qt containers and std containers.

Add snippets showing use of std algorithms with Qt containers.

Task-number: QTBUG-86584
Pick-to: 6.0
Change-Id: I1133a5214a5acd086c37658ca11ab205a19a489b
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
---
 src/corelib/doc/src/containers.qdoc | 51 +++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

(limited to 'src/corelib/doc/src')

diff --git a/src/corelib/doc/src/containers.qdoc b/src/corelib/doc/src/containers.qdoc
index c5b70c2675..5d4b9a2215 100644
--- a/src/corelib/doc/src/containers.qdoc
+++ b/src/corelib/doc/src/containers.qdoc
@@ -379,6 +379,57 @@
     \note The alternative macros Q_FOREACH and Q_FOREVER remain defined
     regardless.
 
+    \section1 Qt containers compared with std containers
+
+    \table
+    \header \li Qt container \li Closest std container
+
+    \row \li \l{QList}<T>
+    \li Similar to std::vector<T>
+
+    \l{QList} and \l{QVector} were unified in Qt 6. Both
+    use the datamodel from QVector. QVector is now an alias to QList.
+
+    This means that QList is not implemented as a linked list, so if
+    you need constant time insert, delete, append or prepend,
+    consider \c std::list<T>. See \l{QList} for details.
+
+    \row \li \l{QVarLengthArray}<T, Prealloc>
+    \li Resembles a mix of std::array<T> and std::vector<T>.
+
+    For performance reasons, QVarLengthArray lives on the stack unless
+    resized. Resizing it automatically causes it to use the heap instead.
+
+    \row \li \l{QStack}<T>
+    \li Similar to std::stack<T>, inherits from \l{QList}.
+
+    \row \li \l{QQueue}<T>
+    \li Similar to std::queue<T>, inherits from \l{QList}.
+
+    \row \li \l{QSet}<T>
+    \li Similar to std::set<T>. Internally, \l{QSet} is implemented with a
+    \l{QHash}.
+
+    \row \li \l{QMap}<Key, T>
+    \li Similar to std::map<T>.
+
+    \row \li \l{QMultiMap}<Key, T>
+    \li Similar to std::multimap<T>.
+
+    \row \li \l{QHash}<Key, T>
+    \li Most similar to std::map<T>.
+
+    \row \li \l{QMultiHash}<Key, T>
+    \li Most similar to std::multimap<T>.
+
+    \endtable
+
+    \section1 Qt containers and std algorithms
+
+    You can used Qt containers with functions from \c{#include <algorithm>}.
+
+    \snippet code/doc_src_containers.cpp 26
+
     \section1 Other Container-Like Classes
 
     Qt includes other template classes that resemble containers in
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