I think optional might be perfect for an issue I have, but there is one
catch.
I have a polymorphic hierarchy that I would like to use with optional, but
optional<Base> is not a base of optional<Derived>. Of course, this isn't
really a problem with optional, par se, but any suggestions on how to store
pointers to optional<T> when T is polymorphic would be appreciated.
I know I can use aggregation like so:
class Base
{
virtual ~Base() { }
};
template <typename T>
class PolyOptional : public Base
{
optional<T> value_;
};
and then just store Base*, but this requires explicit run-time checking of
types which would otherwise be automatic with pointers to T instead of
optional<T>. If this is the only solution, so be it; but any clever
alternatives are welcome.
Dave
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