vsprintf or printf variable arguments

[Mark J Twain via Digitalmars-d-learn]

How can I construct a va_list for vsprintf when all I have is the 
a list of pointers to the data, without their type info?

A va_list seems to be a packed struct of values and/or pointers 
to the data. While I could construct such a list, theoretically, 
I don't always know when I should store an element as a pointer 
or a value.

e.g., ints, floats, and other value types seems to get stored 
directly in the list, while strings and *other* stuff get stored 
as pointers.

I would be nice if a printf variant listed takes only a pointer 
list to all the values, does anything like this exist?

If not, is there any standardization of what is a value in the 
list and what is a pointer so I can attempt to build the list 
properly?