any_ptr

Hi all! any_ptr was a typo in an older documentation, but this leads me to this question: any stores the type values in the template class holder, which is derived from placeholder to provide an uniform interface. This approach works fine for new classes where the data representation is done inside the any class, but for legacy code I would also like to have an any_ptr, which uses a holder that POINTS to a variable rather than containing it. With this I could extend existing classes with algorithms depending on any. Has any_ptr considered in the past and if yes, what have been the reasons to decide against it? Thanks in advance, CL