Hallo,
On 06/01/16 15:37, Marc Feeley wrote:
Of course one way would be to return a double (which has 53 bits of precision) and use NaN to encode “missing tag”. I’m not kidding!
If you don’t like this approach, and I can understand why you wouldn’t, then you have to do the conversion to ___SCMOBJ by directly calling the conversion macros. Something like this:
(define uint32_tag (c-lambda (TIFF* ttag_t) scheme-object " ___U32 val; if (TIFFGetField(___arg1, ___arg2, &val) == 1) { if ((___err = ___U32_to_SCMOBJ (___PSTATE, val, &___result, ___RETURN_POS)) == ___FIX(___NO_ERR)) { ___release_scmobj (___result); } } else { ___result = ___FAL; } "))
Thanks, this looks promising. But I do not understand the call to `___release_scmobj`, wouldn't that release the object that we are returning? Or is it just decrementing some reference count?
Cheers,