Replace custom type traits with std one's

Remove most type traits from qtypetraits.h, but keep the custom
implementation of is_signed/is_unsigned. This gets rid of
BSD-3 licensed code from Google in a public header (hugh!).

The custom implementations for is_signed/is_unsigned are kept
because the implementations in gcc's standard headers do not
work as we expect for enums - both is_signed and is_unsigned
always returns false there - see also
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59027

[ChangeLog][QtCore][General] Qt now relies on type traits from
the C++ standard library.

Change-Id: I3f2188b46949f04ca4482a6ac9afd3482103f0e1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/widgets/graphicsview/qgraphicsitem.h b/src/widgets/graphicsview/qgraphicsitem.h
index 59656f5b0b..36f8aac124 100644
--- a/src/widgets/graphicsview/qgraphicsitem.h
+++ b/src/widgets/graphicsview/qgraphicsitem.h
@@ -1024,14 +1024,14 @@ private:
 
 template <class T> inline T qgraphicsitem_cast(QGraphicsItem *item)
 {
-    typedef typename QtPrivate::remove_cv<typename QtPrivate::remove_pointer<T>::type>::type Item;
+    typedef typename std::remove_cv<typename std::remove_pointer<T>::type>::type Item;
     return int(Item::Type) == int(QGraphicsItem::Type)
         || (item && int(Item::Type) == item->type()) ? static_cast<T>(item) : 0;
 }
 
 template <class T> inline T qgraphicsitem_cast(const QGraphicsItem *item)
 {
-    typedef typename QtPrivate::remove_cv<typename QtPrivate::remove_pointer<T>::type>::type Item;
+    typedef typename std::remove_cv<typename std::remove_pointer<T>::type>::type Item;
     return int(Item::Type) == int(QGraphicsItem::Type)
         || (item && int(Item::Type) == item->type()) ? static_cast<T>(item) : 0;
 }