Ovanes Markarian wrote:
Does anyone have a suggestion as to how I can get a value out of a boost::any for which I don't know the specific type stored in it? if you know the set of types you operate on consider using boost::variant which supports visitor pattern for dispatching of currently stored type.
A subclass method is returning the boost::any, which is conceptually a bool, but different subclasses may implement it as a bool, int, int64_t, etc. I can just static-cast them to bool if I can get the value out of the boost::any, but boost::any_cast gives a bad_any_cast unless I cast it to exactly the right type (which as I noted, the super-class doesn't know)
Another approach could be to introduce an additional level of indirection. Another Holder type of your types and implement for this type operator<<. Than you can always retrieve from boost::any your holder_type instance and apply to your holder_type instance lexical_cast.
Hope that helps. It is difficult to make suggestions, because we don't if you are allowed to modify the interface.
Best Regards, Ovanes If you have "the Boost book" (Beyond the C++ Standard Library: An Introduction to Boost), I think chapter 6 implements something like this to allow streaming of boost::any types.