Add initializer list support in QJsonObject.

It allows to create a QJsonObject instance in C++ by using
initializer list of pairs QString QJsonValue, for example:

QJsonObject o = {{"property1", 1}, {"property2", 2}};

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

Task-number: QTBUG-26606
Change-Id: I67af881e175f427e563e685336c48a5f8466b476
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 42 insertions, 0 deletions

diff --git a/src/corelib/json/qjsonobject.cpp b/src/corelib/json/qjsonobject.cpp
index 94ec9a2818..cfd797990f 100644
--- a/src/corelib/json/qjsonobject.cpp
+++ b/src/corelib/json/qjsonobject.cpp
@@ -116,6 +116,20 @@ QJsonObject::QJsonObject()
 }
 
 /*!
+    \fn QJsonObject::QJsonObject(std::initializer_list<QPair<QString, QJsonValue> > args)
+    \since 5.4
+    Constructs a QJsonObject instance initialized from \a args initialization list.
+    For example:
+    \code
+    QJsonObject object
+    {
+        {"property1", 1},
+        {"property2", 2}
+    };
+    \endcode
+*/
+
+/*!
     \internal
  */
 QJsonObject::QJsonObject(QJsonPrivate::Data *data, QJsonPrivate::Object *object)
@@ -126,6 +140,19 @@ QJsonObject::QJsonObject(QJsonPrivate::Data *data, QJsonPrivate::Object *object)
     d->ref.ref();
 }
 
+/*!
+    This method replaces part of the QJsonObject(std::initializer_list<QPair<QString, QJsonValue>> args) body.
+    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 QJsonObject::initialize()
+{
+    d = 0;
+    o = 0;
+}
 
 /*!
     Destroys the object.
diff --git a/src/corelib/json/qjsonobject.h b/src/corelib/json/qjsonobject.h
index ad3184b1f2..92dd19af5e 100644
--- a/src/corelib/json/qjsonobject.h
+++ b/src/corelib/json/qjsonobject.h
@@ -44,6 +44,10 @@
 
 #include <QtCore/qjsonvalue.h>
 #include <QtCore/qiterator.h>
+#ifdef Q_COMPILER_INITIALIZER_LISTS
+#include <QtCore/qpair.h>
+#include <initializer_list>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -55,6 +59,16 @@ class Q_CORE_EXPORT QJsonObject
 {
 public:
     QJsonObject();
+
+#if defined(Q_COMPILER_INITIALIZER_LISTS) || defined(Q_QDOC)
+    QJsonObject(std::initializer_list<QPair<QString, QJsonValue> > args)
+    {
+        initialize();
+        for (std::initializer_list<QPair<QString, QJsonValue> >::const_iterator i = args.begin(); i != args.end(); ++i)
+            insert(i->first, i->second);
+    }
+#endif
+
     ~QJsonObject();
 
     QJsonObject(const QJsonObject &other);
@@ -195,6 +209,7 @@ private:
     friend Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonObject &);
 
     QJsonObject(QJsonPrivate::Data *data, QJsonPrivate::Object *object);
+    void initialize();
     void detach(uint reserve = 0);
     void compact();