find_overload_match for constructor

Hey everyone,

I'm currently stomped on how to call_function_by_hand for a constructor.
Basically I have a class in C++ which wraps multiple native data types to
the underlying base class like this:

class constant_t: public value_t
{ constant_t (int);
  constant_t (double);
  constant_t (const char *);
}

Now when I have a command line like
(gdb) p $testnr1 + 0.1
I need the function call to the constructor of constant_t so that I can
use the operator+ on the value_t of $testnr1.

I looked through the code and the only thing I could find which came
close to this was the code used for the operator overload on C++ classes
with find_overload_match but I can't quite figure out how I would call
this in case of an overloaded constructor. Do I need to create an object
of type constant_t with it being passed to **args and **objp? In that
case how would I achieve that, as the the created object is kinda what I
want in the first place.

Any help is appreciated,
Lennart