On 6/16/07, Tobias Schwinger <tschwinger@isonews2.com > wrote:

Server Levent Yilmaz wrote:
> I did somehow come up with this dirty trick, though it doesn't quite cut it:
>

<snip code>

>
> any ideas?
>

Yep, here's another dirty trick ;-):

     #include <boost/preprocessor/detail/is_unary.hpp>

     #define SPECIAL (whatever)
     #define IS_SPECIAL BOOST_PP_IS_UNARY

     IS_SPECIAL(a)         // 0
     IS_SPECIAL(b)         // 0
     IS_SPECIAL(SPECIAL)   // 1

It isn't entirely portable to older preprocessors (that's why this code
lives in preprocessor/detail) but should work with latest versions of
the widely-used compilers.

That did it!! Thanks Tobias.

FWIW, I have solved my original problem too. It is in fact not an entirely fun project, but became a helpful little library on its own, useful for mixed language programming (C++ calling Fortran, to be specific). The idea is the "stub code" outlined by Carsten A. Arnholm ( here) Arnholm generates the stub code with an external script. I managed to do it with preprocessor only.

So, the library effectively converts the following:

FORTRAN_FUNCTION   (int, foo, FOO, 3, (CHAR, double*, int&) );
FORTRAN_SUBROUTINE (     bar, BAR, 4, (CHAR, const double&, CHAR, int*) );

into,

#ifdef F77_STUB_REQUIRED

extern "C" void bar_ (const char*, const double&, const char*, int*, size_t, size_t);
inline void BAR (
     internal_character_type v0,
     double* v1,
     internal_character_type v2,
     int& v3
     )
  {
     bar_(v0.p, v1, v2.p, v3, v0.n, v2.n);
  }


#else // in MS compilers

  extern "C" int  __stdcall FOO( const char*, size_t, double*, int&);
  extern "C" void __stdcall BAR( internal_character_type, const double&, internal_character_type, int*);

#endif

The library code is in the vault (fortran.h here) in case anyone is interested.

regards,
Levent

--
Server Levent Yilmaz
Mechanical Engineering
University of Pittsburgh