QStringBuilder: document issues with using "auto" keyword

Cleanup QStringBuilder API docs.

Task-number: QTBUG-104354
Change-Id: I00029c8f4bfdf35869396ac14d7d9ba0da34cdb5
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/corelib/doc/snippets/qstring/stringbuilder.cpp b/src/corelib/doc/snippets/qstring/stringbuilder.cpp
index 6b3175d48a..61b7a9a133 100644
--- a/src/corelib/doc/snippets/qstring/stringbuilder.cpp
+++ b/src/corelib/doc/snippets/qstring/stringbuilder.cpp
@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
+#include <QString>
+
 using namespace Qt::StringLiterals;
 
 //! [0]
@@ -25,3 +27,24 @@ using namespace Qt::StringLiterals;
     QLatin1StringView world("world");
     QString message =  hello % el % world % QChar('!');
 //! [5]
+
+//! [6]
+    QString str("QStringBuilder");
+
+    // "s" type is deduced as QStringBuilder
+    auto s = "Like hot glue, " % str % " concatenates strings";
+
+    // Similarly the return type of this lambda is deduced as QStringBuilder
+    auto concatenateStr = []() {
+        return "Like hot glue, " % str % " concatenates strings";
+    };
+//! [6]
+
+//! [7]
+    QString s = "Like hot glue, " % str % " concatenates strings";
+
+    // With a lambda, specify a trailing return type
+    auto concatenateStr = []() -> QString {
+        return "Like hot glue, " % str % " concatenates strings";
+    };
+//! [7]