From: Calum Grant (calum_at_[hidden])
Date: 2005-07-15 14:37:56
I've been following this dual_state vs optional discussion for a while.
It seems to me that one should really have a policy class that defines
the default behaviour when the value is unassigned. This policy should
define whether to
- throw an exception
- construct an object on the fly
- return a default
- return a null pointer
- whether to return by value or by reference
A second point, can't all this be achieved by adding policies to smart
pointers?
Also, I can't quite see the benefit of having a dual-state that returns
a default value. I mean, why use
boost::dual_state<std::string> data;
when you can simply use
std::string data;
?
Calum