Re: Pointer

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Sébastien wrote:
> > Suggesting, n is returned from the C program:
> >
> > with Interfaces.C;  use Interfaces.C;
> > with Interfaces.C.Strings;  use Interfaces.C.Strings;
> >
> > function Get_It return String is
> >    procedure Internal (N : out size_t; Data : out chars_ptr);
> >    pragma Import (C, Internal, "<C-name>");
> >    Data : chars_ptr;
> >    N : size_t;
> > begin
> >    Internal (Data);
> >    return Value (N, Data);
> > end Get_It;
>
> Yes it's exaclty what I did ... and it's exaclty what I would like to
> avoid :-) Actually, I was looking for a pure Ada solution.
> I think there is a way using an unchecked type conversion, but how to be
> sure of the size of the System.Address?

procedure To_String (Pointer : in System.Address; Length : in Natural)
return String is
   Result : String (1 .. Length);
   for Result'Address use Pointer;
   pragma Import (Ada, Result); -- suppress default initialization
begin
   return Result;
end To_String;

But Dmitryi's solution is safer, of course. HTH

--
Ludovic Brenta.