Doc: Advocate use of std::initializer_list constructor in Q[String]List

We're relying on C++11 since a while, so lets not advertise creating
lists of strings with operator<<() anymore.

Change-Id: I14a3442ff852ac2c106d90c63504eb9ebb737609
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/corelib/doc/snippets/code/src_corelib_tools_qlistdata.cpp

@@ -54,11 +54,14 @@ QList<QDate> dateList;
 //! [0]
 
 
-//! [1]
-QList<QString> list;
-list << "one" << "two" << "three";
-// list: ["one", "two", "three"]
-//! [1]
+//! [1a]
+QList<QString> list = { "one", "two", "three" };
+//! [1a]
+
+
+//! [1b]
+list << "four" << "five";
+//! [1b]
 
 
 //! [2]

src/corelib/doc/snippets/qstringlist/main.cpp

@@ -61,10 +61,13 @@ public:
 Widget::Widget(QWidget *parent)
     : QWidget(parent)
 {
-//! [0]
-    QStringList fonts;
-    fonts << "Arial" << "Helvetica" << "Times" << "Courier";
-//! [0]
+//! [0a]
+    QStringList fonts = { "Arial", "Helvetica", "Times" };
+//! [0a]
+
+//! [0b]
+    fonts << "Courier" << "Verdana";
+//! [0b]
 
 //! [1]
     for (int i = 0; i < fonts.size(); ++i)

src/corelib/tools/qlist.cpp

@@ -408,15 +408,20 @@ void **QListData::erase(void **xi)
     from strings.
 
     QList stores a list of items. The default constructor creates an
-    empty list. To insert items into the list, you can use
-    operator<<():
+    empty list. You can use the initializer-list constructor to create
+    a list with elements:
 
-    \snippet code/src_corelib_tools_qlistdata.cpp 1
+    \snippet code/src_corelib_tools_qlistdata.cpp 1a
 
     QList provides these basic functions to add, move, and remove
     items: insert(), replace(), removeAt(), move(), and swap(). In
     addition, it provides the following convenience functions:
-    append(), prepend(), removeFirst(), and removeLast().
+    append(), \l{operator<<()}, \l{operator+=()}, prepend(), removeFirst(),
+    and removeLast().
+
+    \l{operator<<()} allows to conveniently add multiple elements to a list:
+
+    \snippet code/src_corelib_tools_qlistdata.cpp 1b
 
     QList uses 0-based indexes, just like C++ arrays. To access the
     item at a particular index position, you can use operator[](). On

src/corelib/tools/qstringlist.cpp

@@ -98,14 +98,25 @@ QT_BEGIN_NAMESPACE
 
     \tableofcontents
 
+    \section1 Initializing
+
+    The default constructor creates an empty list. You can use the
+    initializer-list constructor to create a list with elements:
+
+    \snippet qstringlist/main.cpp 0a
+
     \section1 Adding Strings
 
     Strings can be added to a list using the \l
+    {QList::insert()}{insert()} \l
     {QList::append()}{append()}, \l
     {QList::operator+=()}{operator+=()} and \l
-    {QStringList::operator<<()}{operator<<()} functions. For example:
+    {operator<<()} functions.
 
-    \snippet qstringlist/main.cpp 0
+    \l{operator<<()} can be used to
+    conveniently add multiple elements to a list:
+
+    \snippet qstringlist/main.cpp 0b
 
     \section1 Iterating Over the Strings