Call std::addressof instead of operator& in QDebug::toString

QDebug::toString intends to pass the input object's address to its
nested implementation, but was calling operator& which does not work
with types that has a custom overload. Calling std::addressof fixes this
problem.

Fixes: QTBUG-127510
Pick-to: 6.8
Change-Id: Ie608f7b1a63c4032246b6ff98a3651695f0536ca
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

src/corelib/io/qdebug.h

@@ -22,6 +22,7 @@
 #include <chrono>
 #include <list>
 #include <map>
+#include <memory>
 #include <optional>
 #include <string>
 #include <string_view>
@@ -241,7 +242,7 @@ public:
     template <typename T>
     static QString toString(const T &object)
     {
-        return toStringImpl(&streamTypeErased<T>, &object);
+        return toStringImpl(&streamTypeErased<T>, std::addressof(object));
     }
 
     template <typename T>

tests/auto/corelib/io/qdebug/tst_qdebug.cpp

@@ -1343,6 +1343,19 @@ void tst_QDebug::toString() const
         stream.nospace() << &qobject;
         QCOMPARE(QDebug::toString(&qobject), expectedString);
     }
+
+    // Overloaded operator&
+    {
+        struct TypeWithAddressOf
+        {
+            int* operator&() const { return nullptr; }
+            operator QByteArray() const { return "test"; }
+        };
+
+        TypeWithAddressOf object;
+        QString expectedString {"\"test\""};
+        QCOMPARE(QDebug::toString(object), expectedString);
+    }
 }
 
 void tst_QDebug::noQVariantEndlessRecursion() const