Use <type_traits> to properly have QVector<T>::parameter_type

That allows us to pass by value for all fundamental and pointer types.

This requires some magic to remove methods taking a T&& to avoid
ambiguous overloads for QVector<int/qsizetype>. Remove them for all
cases where parameter_type is T, as copying or moving will do
exactly the same thing for those types.

Change-Id: I8133fecd3ac29bb8f6ae57376e680bc3d616afbf
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/corelib/tools/qarraydatapointer.h b/src/corelib/tools/qarraydatapointer.h
index 3d850c0144..1f81689af3 100644
--- a/src/corelib/tools/qarraydatapointer.h
+++ b/src/corelib/tools/qarraydatapointer.h
@@ -55,6 +55,9 @@ private:
 public:
     typedef typename Data::iterator iterator;
     typedef typename Data::const_iterator const_iterator;
+    enum { pass_parameter_by_value = std::is_fundamental<T>::value || std::is_pointer<T>::value };
+
+    typedef typename std::conditional<pass_parameter_by_value, T, const T &>::type parameter_type;
 
     QArrayDataPointer() noexcept
         : d(Data::sharedNull()), ptr(Data::sharedNullData()), size(0)
@@ -131,8 +134,8 @@ public:
 
     ~QArrayDataPointer()
     {
-        if (!d->deref()) {
-            if (d->isMutable())
+        if (!deref()) {
+            if (isMutable())
                 (*this)->destroyAll();
             Data::deallocate(d);
         }