Re: Passing Floats Ada->C

[kst@king.cts.com (Keith Thompson)]

I've deleted comp.lang.c++ from the Newsgroups: header, since this isn't
a C++ question.

Matthew Heaney (matthew_heaney@acm.org) wrote:
[...]
> The problem I've had in the past is that Float in Ada sometimes means
> something else in C, say long float.  Make sure the underlying
> representations are the same.
> 
> If you're using Ada 95, you shouldn't have a problem if you stick to the
> types in package Interfaces.C, and remember to use pragma Convention (C)
> on your subprograms.

Note that in C, if there's no prototype (or a ", ..." prototype) in scope,
arguments of type float are promoted to type double.

This is more likely to be a problem passing floats from C to Ada, but
it's something to watch out for.  As long as you properly prototype
everything, it should seldom be an issue.

-- 
Keith Thompson (The_Other_Keith) kst@cts.com <http://www.ghoti.net/~kst> <*>
Qualcomm, San Diego, California, USA  <http://www.qualcomm.com>
It takes a Viking to raze a village.