How to iterate over boost::variant

as the title is pretty explanatory, how is the best way to iterate over a boost::variant, std::vector> variable?

Say that I have a structure:

struct foobar{
    enum typeOfVariant {intVariant, StringVariant}
    boost::variant<std::vector<int>, std::vector<String>> variable;
    }

That i receive at a certain point with the guarantee that the enum is corelated with the type from the variant.

To achieve maybe something like: boost::variant, std::vector> var;

for (auto t in var)
{
//do something
}

^this might be the ideal way.

Or to force conversion to a std::vector or std::vector, based on the enum type?