Documentation: Expand documentation on how to iterate Qt containers

Introduce a section on iteration and add range-based for and index.

Pick-to: 6.4 6.2
Task-number: QTBUG-108687
Change-Id: Icb1ff55049361769f7c0b042d42f70148dd07c2e
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/src/corelib/doc/snippets/code/doc_src_containers.cpp b/src/corelib/doc/snippets/code/doc_src_containers.cpp
index ab7f8c8b7f..29d9b584d0 100644
--- a/src/corelib/doc/snippets/code/doc_src_containers.cpp
+++ b/src/corelib/doc/snippets/code/doc_src_containers.cpp
@@ -16,6 +16,27 @@ private:
 };
 //! [0]
 
+//! [range_for]
+QList<QString> list = {"A", "B", "C", "D"};
+for (const auto &item : list) {
+   ...
+}
+//! [range_for]
+
+//! [range_for_as_const]
+QList<QString> list = {"A", "B", "C", "D"};
+for (const auto &item : std::as_const(list)) {
+    ...
+}
+//! [range_for_as_const]
+
+//! [index]
+QList<QString> list = {"A", "B", "C", "D"};
+for (qsizetype i = 0; i < list.size(); ++i) {
+    const auto &item = list.at(i);
+    ...
+}
+//! [index]
 
 //! [1]
 QList<QString> list = {"A", "B", "C", "D"};