Add initializer list support in QJsonArray

It allows to create a QJsonArray instance in C++ by using
a similar expression to JSON. For example:

QJsonArray a = {1, 2, 4};

[ChangeLog][QtCore][QtJson] QJsonArray now supports
C++11 initializer lists.

Task-number: QTBUG-26606
Change-Id: Icc352e518d9649d24176c89e7113d200d5c50b0d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 39 insertions, 0 deletions

diff --git a/src/corelib/json/qjsonarray.cpp b/src/corelib/json/qjsonarray.cpp
index 61bb158ff5..c1e831192a 100644
--- a/src/corelib/json/qjsonarray.cpp
+++ b/src/corelib/json/qjsonarray.cpp
@@ -138,6 +138,18 @@ QJsonArray::QJsonArray()
 }
 
 /*!
+    \fn QJsonArray::QJsonArray(std::initializer_list<QJsonValue> args)
+    \since 5.4
+    Creates an array initialized from \a args initialization list.
+
+    QJsonArray can be constructed in a way similar to JSON notation,
+    for example:
+    \code
+    QJsonArray array = { 1, 2.2, QString() };
+    \endcode
+ */
+
+/*!
     \internal
  */
 QJsonArray::QJsonArray(QJsonPrivate::Data *data, QJsonPrivate::Array *array)
@@ -149,6 +161,19 @@ QJsonArray::QJsonArray(QJsonPrivate::Data *data, QJsonPrivate::Array *array)
 }
 
 /*!
+    This method replaces part of QJsonArray(std::initializer_list<QJsonValue> args) .
+    The constructor needs to be inline, but we do not want to leak implementation details
+    of this class.
+    \note this method is called for an uninitialized object
+    \internal
+ */
+void QJsonArray::initialize()
+{
+    d = 0;
+    a = 0;
+}
+
+/*!
     Deletes the array.
  */
 QJsonArray::~QJsonArray()
diff --git a/src/corelib/json/qjsonarray.h b/src/corelib/json/qjsonarray.h
index 84c162f0a0..4cada7cec1 100644
--- a/src/corelib/json/qjsonarray.h
+++ b/src/corelib/json/qjsonarray.h
@@ -44,6 +44,9 @@
 
 #include <QtCore/qjsonvalue.h>
 #include <QtCore/qiterator.h>
+#if defined(Q_COMPILER_INITIALIZER_LISTS)
+#include <initializer_list>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -56,6 +59,16 @@ class Q_CORE_EXPORT QJsonArray
 {
 public:
     QJsonArray();
+
+#if defined(Q_COMPILER_INITIALIZER_LISTS) || defined(Q_QDOC)
+    QJsonArray(std::initializer_list<QJsonValue> args)
+    {
+        initialize();
+        for (std::initializer_list<QJsonValue>::const_iterator i = args.begin(); i != args.end(); ++i)
+            append(*i);
+    }
+#endif
+
     ~QJsonArray();
 
     QJsonArray(const QJsonArray &other);
@@ -212,6 +225,7 @@ private:
     friend Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonArray &);
 
     QJsonArray(QJsonPrivate::Data *data, QJsonPrivate::Array *array);
+    void initialize();
     void compact();
     void detach(uint reserve = 0);