/// <summary>
/// For use by the ProxyGen, since the users of it know only about the base type used
/// to generate the proxy. The struct used internally is not exposed, and so users
/// of proxy classes could not write a ModificationDelegate which works on an argument
/// whose type is that hidden struct.
/// </summary>
public void Commute(Action perform)
{
Shield.EnlistStrictCommute(perform, this);
RaiseChanged();
}
/// <summary>
/// The action is performed just before commit, and reads the latest
/// data. If it conflicts, only it is retried. If it succeeds,
/// we (try to) commit with the same write stamp along with it.
/// But, if you access this Shielded, it gets executed directly in this transaction.
/// The Changed event is raised only when the commute is enlisted, and not
/// when (and every time, given possible repetitions..) it executes.
/// </summary>
public void Commute(ModificationDelegate perform)
{
Shield.EnlistStrictCommute(
() => perform(ref PrepareForWriting(true).Value), this);
RaiseChanged();
}