Add QVariant container iteration API.

A new set of classes is introduced for iterating over the contents
of a container within a QVariant without knowing the exact type of
the container, but with the guarantee that the element type within
the container is a metatype.

The implementation of the iterable interface uses
the stl-compatible container API so that we can also iterate over stl
containers, or any other container which also conforms to stl norms.

This enables the functionality in the bug report.

Task-number: QTBUG-23566

Change-Id: I92a2f3458516de201b8f0e470982c4d030e8ac8b
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index 44246e05ca..37ff858530 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -1962,6 +1962,18 @@ const QMetaObject *QMetaType::metaObjectForType(int type)
     \sa Q_DECLARE_METATYPE(), QMetaType::type()
 */
 
+/*!
+    \fn bool qRegisterSequentialConverter()
+    \relates QMetaType
+    \since 5.2
+
+    Registers a sequential container so that it can be converted to
+    a QVariantList. If compilation fails, then you probably forgot to
+    Q_DECLARE_METATYPE the value type.
+
+    \sa QVariant::canConvert()
+*/
+
 namespace {
 class TypeInfo {
     template<typename T, bool IsAcceptedType = DefinedTypesFilter::Acceptor<T>::IsAccepted>