C++ FSM design and ownership

Question

I would like to implement a FSM/\"pushdown automaton\" parser for this syntax: parser with scopes and conditionals which has already been \"lexed\" into Finite State Machine

Answer 1

Feel free to still post your take on this, but I have figured out how to handle everything gracefully:

First: my event loop will keep a pointer to the last State* created.

Second: Each State has a pointer to the parent State, initialized in the constructor, defaulting to 0 (memory leak if used for anything but the first State*); this guarantees that no State will go out of scope.

Third: State* endOfState() function which does exactly this (and I'm particularly proud of this.

State* State::endOfState()
{
    State* parent = m_parent; // keep member pointer after suicide
    delete this;
    return parent;
}

When this is called from within a subclass's event(), it will properly delete itself, and return the parent pointer (going one up in the ladder).

If this still contains a leak, please inform me. If the solution is not clear, please ask :)

PS: for all fairness, inspiration was stolen from http://www.codeguru.com/forum/showthread.php?t=179284