QCborStreamReader: use std::bit_cast in _toFloatingPoint

Change-Id: Ic5b53111dbdb9073bb45fffd7c1bcb0c80b5df62
Reviewed-by: Marc Mutz <marc.mutz@qt.io>

src/corelib/serialization/qcborstreamreader.h

@@ -11,6 +11,9 @@
 #include <QtCore/qstring.h>
 #include <QtCore/qstringview.h>
 
+#ifdef __cpp_lib_bit_cast
+#include <bit>
+#endif
 #include <memory>
 
 QT_REQUIRE_CONFIG(cborstreamreader);
@@ -188,9 +191,13 @@ private:
     {
         using UIntFP = typename QIntegerForSizeof<FP>::Unsigned;
         UIntFP u = UIntFP(value64);
+#ifdef __cpp_lib_bit_cast
+        return std::bit_cast<FP>(u);
+#else
         FP f;
         memcpy(static_cast<void *>(&f), &u, sizeof(f));
         return f;
+#endif
     }
 
     friend QCborStreamReaderPrivate;