Including code in Inline::C *before* the standard headers

[Sisyphus]

Hi,

The xs code that Inline::C auto-generates normally begins with:

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

Does Inline::C currently accommodate the inclusion of any pre-processing
code *before* that block ?

Afaict, it doesn't ... but perhaps it's just that I've missed it.

I know of at least one example (on Windows) where such capability would be
convenient, and can think of (hypothetical) situations where it would be
necessary.

Let's say you need Inline::C to auto-generate an XS file that begins with:

#ifdef SOMETHING
#define SOME_VALUE 0
#else
#define SOME_VALUE 1
#endif
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

How would you achieve that with Inline::C ? (I couldn't find a way.)

To add to the mystery, C.pm assigns the following:

$o->{ILSM}{AUTO_INCLUDE} ||= <<END;
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "INLINE.h"
END

Now the '||=' suggests it's possible that AUTO_INCLUDE has already been
defined - yet, again, I failed to see a way to have it already defined by
the time that code was executed.

Cheers,
Rob