QPair: specialise QTypeInfo based on the typeinfos of its arguments

Specialise QTypeInfo<QPair<T1,T2>> based on the properties of
T1 and T2:

- If either T1 or T2 is Q_COMPLEX_TYPE, so is QPair<T1,T2>.
- Otherwise, if either T1 or T2 is Q_MOVABLE_TYPE, so is QPair<T1,T2>.
- Otherwise, QPair<T1,T2> is Q_PRIMITIVE_TYPE.

Change-Id: I8aecbd37e3b7924f77f38967498deabf1a19ca24
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/corelib/tools/qpair.h b/src/corelib/tools/qpair.h
index 501f2af3e6..29eb58bd22 100644
--- a/src/corelib/tools/qpair.h
+++ b/src/corelib/tools/qpair.h
@@ -65,6 +65,22 @@ struct QPair
     T2 second;
 };
 
+// mark QPair<T1,T2> as complex/movable/primitive depending on the
+// typeinfos of the constituents:
+template<class T1, class T2>
+class QTypeInfo< QPair<T1, T2> >
+{
+public:
+    enum {
+        isComplex = QTypeInfo<T1>::isComplex || QTypeInfo<T2>::isComplex,
+        isStatic  = QTypeInfo<T1>::isStatic  || QTypeInfo<T2>::isStatic,
+        isLarge   = sizeof(QPair<T1, T2>) > sizeof(void*),
+        isPointer = false,
+        isDummy   = false,
+        sizeOf    = sizeof(QPair<T1, T2>)
+    };
+};
+
 template <class T1, class T2>
 Q_INLINE_TEMPLATE bool operator==(const QPair<T1, T2> &p1, const QPair<T1, T2> &p2)
 { return p1.first == p2.first && p1.second == p2.second; }