QVarLengthArray: Add initializer_list constructor

Implement an initializer_list constructor, which was probably
just forgotten so far. Technically this is a SC incompatible change,
since

  QVarLengthArray<int> array = {10};

will now create an array with one element 10, instead of an empty array
with a reserved size of 10. Anyhow, keeping the inconsistency with the
STL / other Qt containers here would certainly do more harm than good
in the long run.

Task-number: QTBUG-45047
Change-Id: I4675880f93e141181250939942fa32300916b0e3
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

2 files changed, 22 insertions, 0 deletions

diff --git a/src/corelib/tools/qvarlengtharray.h b/src/corelib/tools/qvarlengtharray.h
index 54d97d8762..32f621c809 100644
--- a/src/corelib/tools/qvarlengtharray.h
+++ b/src/corelib/tools/qvarlengtharray.h
@@ -42,6 +42,9 @@
 #include <string.h>
 #include <stdlib.h>
 #include <algorithm>
+#ifdef Q_COMPILER_INITIALIZER_LISTS
+#include <initializer_list>
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -62,6 +65,14 @@ public:
         append(other.constData(), other.size());
     }
 
+#ifdef Q_COMPILER_INITIALIZER_LISTS
+    QVarLengthArray(std::initializer_list<T> args)
+        : a(Prealloc), s(0), ptr(reinterpret_cast<T *>(array))
+    {
+        append(args.begin(), args.size());
+    }
+#endif
+
     inline ~QVarLengthArray() {
         if (QTypeInfo<T>::isComplex) {
             T *i = ptr + s;
diff --git a/src/corelib/tools/qvarlengtharray.qdoc b/src/corelib/tools/qvarlengtharray.qdoc
index 6cc9f62c5a..d1b87f381e 100644
--- a/src/corelib/tools/qvarlengtharray.qdoc
+++ b/src/corelib/tools/qvarlengtharray.qdoc
@@ -100,6 +100,17 @@
     \l{default-constructed value}.
 */
 
+
+/*! \fn QVarLengthArray::QVarLengthArray(std::initializer_list<T> args)
+    \since 5.5
+
+    Constructs an array from the std::initializer_list given by \a args.
+
+    This constructor is only enabled if the compiler supports C++11 initializer
+    lists.
+*/
+
+
 /*! \fn QVarLengthArray::~QVarLengthArray()
 
     Destroys the array.