You should be able to use C++ Class instances like normal Lisp object.
C++ classes are automatically deleted when their Lisp object gets garbage collected;
except when they (QObjects) have a parent and thus the parent is responsible for
their deletion. When a qt:object
has a parent, a strong
reference is kept to prevent the garbage collection removing it until the parent is deleted.
Ownership transfer for non QObject instances is mostly unimplemented.