Re: Interfacing Ada with C

[tmoran@acm.org]

>The prototype for this function in C would normally be:
>
>    void one(wide_string w);
  As you've noted, what C calls a wide_string is not the same thing as
what Ada calls a Wide_String.  If a C wide_string is a null terminated
array of wchar_t, then you might try

    subtype variable_length_wide_string  -- known length (size_t) so no bounds
      is Interfaces.C.wchar_array(Interfaces.C.size_t);

    procedure One(C_Name : in out variable_length_wide_string);
    pragma Export(C, One, "one");
    ...
    procedure One(C_Name : in out variable_length_wide_string) is
      Name : Wide_String := Interfaces.C.To_Ada(C_Name);
    begin
      -- use/modify Name
      C_Name(0 .. Interfaces.C.Size_T(Name'length)) := Interfaces.C.To_C(Name);
    end One;