Feature Request: bool any_regular::holds<T>() #130

I'd love it if any_regular had a holds<T> routine (similar to std::variant). It would make checking for the type of the thing within the regular much more terse and easy to read.

Old:

if (my_regular.type_info() = typeid(dictionary_t)) {...

New:

if (my_regular.holds<dictionary_t>()) {...

Another option would be a routine that returns a pointer, so if the underlying type matches the caller doesn't have to go back in to get the value. This example is a free function but a member function would work as well:

template <class T>
inline const T* holds_cast(const adobe::any_regular_t& x) {
    if (x.holds<T>()) {
        return &x.cast<T>();
    }
    return nullptr;
}