I recently meet a problem while "playing" with the state pattern. I
was wondering if each of the member function dedicated to handle
events open(), close(), ack() could be change to something like
process(openEv& ev), process(closeEv& ev), ... no problem with this
point. Going further in this way, i thought that the process member
function would be a great candidate for a template. Hum ... it is
not. The process function have to be virtual in the base state class.
Trying to approach something similar, here is what i did :
I used a variant type (boost::variant) that holds any of my event:
typedef boost::variant<pdu1,pdu2,pdu3> pdu;
In the base state class I defined a virtual process(pdu p) and then a
process(pdu p) in each concrete state class that uses a visitor
(inherited from boost::static_visitor) to call the process(xxxEv).
I'd like to know if this is a pertinent solution or if this simply
highlight that if i need to do something like that, something is
wrong in the design.
'boost::variant'. Every derived class then could check if he has
RTTI (or pseudo-RTTI) way. It just seems to me that RT polymorphism