When I use "int()" in perl, what I actually wanted was C's cast-to-int or JavaScript's parseInt()

I don't know of any perl function that will do that.
I'd do it as an XSub:

SV * _to_IV(SV * in) {
  if(SvNV(in) < 0) return newSViv(SvIV(in));
  return newSVuv(SvUV(in));
}
[download]

However, in your case, assuming that $limit > ~0 >> 1, you could just do it as:

IV _to_IV(SV * in) {
  return SvIV(in);
}
[download]

which (if I'm thinking correctly) would still reject arguments greater than ~0 >> 1 because $count is negative.

Of course, you might prefer to just check that the arg is not a NaN, if you trust the NaN != NaN test or POSIX::isnan or somesuch.

Cheers,
Rob