>>>>> On Thu, 25 Apr 2013 20:55:38 -0600, Zach said: > > > (constant (+huge-val+ "HUGE_VAL") :type integer) > > > > then > > > > (with-foreign-object (huge-ptr :uint64) > > (setf (mem-ref huge-ptr :uint64) +huge-val+) > > (nlopt-set-lower-bound opts huge-ptr)) > > I have also been thinking along these lines. The only thing I worry about > is whether this is strictly correct or just correct in practice. Is there > a guarantee that a double float is always the same size as a uint64. It's > true on every platform I have ever programmed for (I think), but will it > always be true? Back when I programmed in C more often, hard coding data > type sizes into a program just seemed wrong so I didn't do it, so I guess I > wouldn't know. Perhaps I am sweating a non-issue...
That's not the only problem -- on some platforms, HUGE_VAL is not a compile-time constant. It looks like the only portable way to get the value is to write a C helper function to return it. -- Martin Simmons LispWorks Ltd http://www.lispworks.com/
